StringBuilder.AppendFormat StringBuilder.AppendFormat StringBuilder.AppendFormat StringBuilder.AppendFormat Method

定義

將處理複合格式字串所傳回的字串 (其中包含零或更多的格式項目) 附加至這個執行個體。Appends the string returned by processing a composite format string, which contains zero or more format items, to this instance. 每一個格式項目會由對應之物件引數的字串表示所取代。Each format item is replaced by the string representation of a corresponding object argument.

多載

AppendFormat(IFormatProvider, String, Object, Object, Object) AppendFormat(IFormatProvider, String, Object, Object, Object) AppendFormat(IFormatProvider, String, Object, Object, Object) AppendFormat(IFormatProvider, String, Object, Object, Object)

將處理複合格式字串所傳回的字串 (其中包含零或更多的格式項目) 附加至這個執行個體。Appends the string returned by processing a composite format string, which contains zero or more format items, to this instance. 使用指定的格式提供者,將每個格式項目取代為三個引數中的其中一個字串表示。Each format item is replaced by the string representation of either of three arguments using a specified format provider.

AppendFormat(String, Object) AppendFormat(String, Object) AppendFormat(String, Object) AppendFormat(String, Object)

將處理複合格式字串所傳回的字串 (其中包含零或更多的格式項目) 附加至這個執行個體。Appends the string returned by processing a composite format string, which contains zero or more format items, to this instance. 每一個格式項目都會取代為單一引數的字串表示。Each format item is replaced by the string representation of a single argument.

AppendFormat(String, Object[]) AppendFormat(String, Object[]) AppendFormat(String, Object[]) AppendFormat(String, Object[])

將處理複合格式字串所傳回的字串 (其中包含零或更多的格式項目) 附加至這個執行個體。Appends the string returned by processing a composite format string, which contains zero or more format items, to this instance. 每一個格式項目會由參數陣列中對應之引數的字串表示所取代。Each format item is replaced by the string representation of a corresponding argument in a parameter array.

AppendFormat(IFormatProvider, String, Object) AppendFormat(IFormatProvider, String, Object) AppendFormat(IFormatProvider, String, Object) AppendFormat(IFormatProvider, String, Object)

將處理複合格式字串所傳回的字串 (其中包含零或更多的格式項目) 附加至這個執行個體。Appends the string returned by processing a composite format string, which contains zero or more format items, to this instance. 使用指定的格式提供者,將每個格式項目取代為單一引數的字串表示。Each format item is replaced by the string representation of a single argument using a specified format provider.

AppendFormat(IFormatProvider, String, Object[]) AppendFormat(IFormatProvider, String, Object[]) AppendFormat(IFormatProvider, String, Object[]) AppendFormat(IFormatProvider, String, Object[])

將處理複合格式字串所傳回的字串 (其中包含零或更多的格式項目) 附加至這個執行個體。Appends the string returned by processing a composite format string, which contains zero or more format items, to this instance. 每一個格式項目會由參數陣列 (此參數陣列使用所指定的格式提供者) 中對應之物件引數的字串表示所取代。Each format item is replaced by the string representation of a corresponding argument in a parameter array using a specified format provider.

AppendFormat(String, Object, Object) AppendFormat(String, Object, Object) AppendFormat(String, Object, Object) AppendFormat(String, Object, Object)

將處理複合格式字串所傳回的字串 (其中包含零或更多的格式項目) 附加至這個執行個體。Appends the string returned by processing a composite format string, which contains zero or more format items, to this instance. 每一個格式項目都會取代為兩個引數中任一個的字串表示。Each format item is replaced by the string representation of either of two arguments.

AppendFormat(IFormatProvider, String, Object, Object) AppendFormat(IFormatProvider, String, Object, Object) AppendFormat(IFormatProvider, String, Object, Object) AppendFormat(IFormatProvider, String, Object, Object)

將處理複合格式字串所傳回的字串 (其中包含零或更多的格式項目) 附加至這個執行個體。Appends the string returned by processing a composite format string, which contains zero or more format items, to this instance. 使用指定的格式提供者,將每個格式項目取代為兩個引數中的其中一個字串表示。Each format item is replaced by the string representation of either of two arguments using a specified format provider.

AppendFormat(String, Object, Object, Object) AppendFormat(String, Object, Object, Object) AppendFormat(String, Object, Object, Object) AppendFormat(String, Object, Object, Object)

將處理複合格式字串所傳回的字串 (其中包含零或更多的格式項目) 附加至這個執行個體。Appends the string returned by processing a composite format string, which contains zero or more format items, to this instance. 每一個格式項目都會取代為三個引數中任一個的字串表示。Each format item is replaced by the string representation of either of three arguments.

AppendFormat(IFormatProvider, String, Object, Object, Object) AppendFormat(IFormatProvider, String, Object, Object, Object) AppendFormat(IFormatProvider, String, Object, Object, Object) AppendFormat(IFormatProvider, String, Object, Object, Object)

將處理複合格式字串所傳回的字串 (其中包含零或更多的格式項目) 附加至這個執行個體。Appends the string returned by processing a composite format string, which contains zero or more format items, to this instance. 使用指定的格式提供者,將每個格式項目取代為三個引數中的其中一個字串表示。Each format item is replaced by the string representation of either of three arguments using a specified format provider.

public:
 System::Text::StringBuilder ^ AppendFormat(IFormatProvider ^ provider, System::String ^ format, System::Object ^ arg0, System::Object ^ arg1, System::Object ^ arg2);
public System.Text.StringBuilder AppendFormat (IFormatProvider provider, string format, object arg0, object arg1, object arg2);
member this.AppendFormat : IFormatProvider * string * obj * obj * obj -> System.Text.StringBuilder
Public Function AppendFormat (provider As IFormatProvider, format As String, arg0 As Object, arg1 As Object, arg2 As Object) As StringBuilder

參數

provider
IFormatProvider IFormatProvider IFormatProvider IFormatProvider

物件,提供特定文化特性格式資訊。An object that supplies culture-specific formatting information.

format
String String String String

複合格式字串。A composite format string.

arg0
Object Object Object Object

要格式化的第一個物件。The first object to format.

arg1
Object Object Object Object

要格式化的第二個物件。The second object to format.

arg2
Object Object Object Object

要格式化的第三個物件。The third object to format.

傳回

完成附加作業之後,這個執行個體的參考。A reference to this instance after the append operation has completed. 在附加作業之後,此執行個體會包含此作業之前已存在的所有資料,並後置有 format 的複本,其中的任何格式規格都會由對應物件引數的字串表示所取代。After the append operation, this instance contains any data that existed before the operation, suffixed by a copy of format where any format specification is replaced by the string representation of the corresponding object argument.

例外狀況

format 無效。format is invalid.

-或--or- 格式項目的索引小於 0 (零) 或大於等於 3 (三)。The index of a format item is less than 0 (zero), or greater than or equal to 3 (three).

展開後的字串長度會超過 MaxCapacityThe length of the expanded string would exceed MaxCapacity.

範例

下列範例會使用AppendFormat(IFormatProvider, String, Object, Object, Object)方法,以說明的布林值結果And整數值的作業。The following example uses the AppendFormat(IFormatProvider, String, Object, Object, Object) method to illustrate the result of a Boolean And operation with integer values. 請注意,格式字串包含六個格式項目,此方法有三個項目在其引數清單中,因為每個項目兩種不同方式格式化。Note that the format string includes six format items, but the method has only three items in its argument list, because each item is formatted in two different ways.

using System;
using System.Globalization;
using System.Text;

public class Example
{
   public static void Main()
   {
      Random rnd = new Random();
      CultureInfo culture = CultureInfo.CreateSpecificCulture("fr-FR");
      StringBuilder sb = new StringBuilder();
      string formatString = "    {0,12:N0} ({0,8:X8})\n" +
                            "And {1,12:N0} ({1,8:X8})\n" +
                            "  = {2,12:N0} ({2,8:X8})\n";
      for (int ctr = 0; ctr <= 2; ctr++) {
         int value1 = rnd.Next();
         int value2 = rnd.Next();
         sb.AppendFormat(culture, formatString,
                         value1, value2, value1 & value2).
                         AppendLine();
      }
      Console.WriteLine(sb.ToString());
   }
}
// The example displays output like the following:
//           1 984 112 195 (76432643)
//       And 1 179 778 511 (4651FDCF)
//         = 1 178 674 243 (46412443)
//
//           2 034 813 710 (7948CB0E)
//       And  569 333 976 (21EF58D8)
//         =  558 385 160 (21484808)
//
//            126 717 735 (078D8F27)
//       And 1 830 715 973 (6D1E8245)
//         =   84 705 797 (050C8205)
Imports System.Globalization
Imports System.Text

Public Module Example
   Public Sub Main()
      Dim rnd As New Random()
      Dim culture As CultureInfo = CultureInfo.CreateSpecificCulture("fr-FR")
      Dim sb As New StringBuilder()
      Dim formatString As String = "    {0,12:N0} ({0,8:X8})" + vbCrLf +
                                   "And {1,12:N0} ({1,8:X8})" + vbCrLf +
                                   "  = {2,12:N0} ({2,8:X8})" + vbCrLf
      For ctr As Integer = 0 To 2
         Dim value1 As Integer = rnd.Next()
         Dim value2 As Integer = rnd.Next()
         sb.AppendFormat(culture, formatString,
                         value1, value2, value1 And value2).AppendLine()
      Next
      Console.WriteLine(sb.ToString())
   End Sub
End Module
' The example displays the following output:
'           1 984 112 195 (76432643)
'       And 1 179 778 511 (4651FDCF)
'         = 1 178 674 243 (46412443)
'
'           2 034 813 710 (7948CB0E)
'       And  569 333 976 (21EF58D8)
'         =  558 385 160 (21484808)
'
'            126 717 735 (078D8F27)
'       And 1 830 715 973 (6D1E8245)
'         =   84 705 797 (050C8205)

備註

這個方法會使用複合格式功能物件的值轉換成其文字表示,並將該表示內嵌在目前的.NET frameworkStringBuilder物件。This method uses the composite formatting feature of the .NET Framework to convert the value of an object to its text representation and embed that representation in the current StringBuilder object.

format參數是由零個或多個文字執行混合零或多個索引的預留位置,稱為格式項目,對應至這個方法的參數清單中的物件。The format parameter consists of zero or more runs of text intermixed with zero or more indexed placeholders, called format items, that correspond to objects in the parameter list of this method. 格式化的程序會將每個格式項目取代對應的物件的字串表示。The formatting process replaces each format item with the string representation of the corresponding object.

格式項目的語法如下所示:The syntax of a format item is as follows:

{index[,length][:formatString]}{index[,length][:formatString]}

在方括號中的元素是選擇性的元素。Elements in square brackets are optional. 下表說明每個元素。The following table describes each element.

元素Element 描述Description
indexindex 參數清單中要格式化之物件的以零為起始位置。The zero-based position in the parameter list of the object to be formatted. 如果所指定的物件indexnull,格式項目取代為String.EmptyIf the object specified by index is null, the format item is replaced by String.Empty. 如果在沒有參數index位置,FormatException就會擲回。If there is no parameter in the index position, a FormatException is thrown.
,length,length 參數的字串表示法中的字元數目下限。The minimum number of characters in the string representation of the parameter. 如果是正數,參數會靠右對齊;如果是負數,它是靠左對齊。If positive, the parameter is right-aligned; if negative, it is left-aligned.
:formatString:formatString 標準或自訂格式字串所支援的參數。A standard or custom format string that is supported by the parameter.

注意

搭配日期和時間值的標準和自訂格式字串,請參閱 < 標準日期和時間格式字串自訂日期和時間格式字串For the standard and custom format strings used with date and time values, see Standard Date and Time Format Strings and Custom Date and Time Format Strings. 針對搭配數值使用標準和自訂格式字串,請參閱標準數值格式字串自訂數值格式字串For the standard and custom format strings used with numeric values, see Standard Numeric Format Strings and Custom Numeric Format Strings. 列舉型別搭配使用的標準格式字串,請參閱 < 列舉格式字串For the standard format strings used with enumerations, see Enumeration Format Strings.

provider參數指定IFormatProvider實作,可提供格式設定資訊arg0arg1The provider parameter specifies an IFormatProvider implementation that can provide formatting information for arg0 and arg1. provider 可以是下列任何項目:provider can be any of the following:

  • ACultureInfo提供特定文化特性格式資訊的物件。A CultureInfo object that provides culture-specific formatting information.

  • ANumberFormatInfo提供特定文化特性格式資訊的物件arg0arg1如果它們是數值。A NumberFormatInfo object that provides culture-specific formatting information for arg0 or arg1 if they are numeric values.

  • ADateTimeFormatInfo提供特定文化特性格式資訊的物件arg0arg1,或arg2有日期和時間值。A DateTimeFormatInfo object that provides culture-specific formatting information for arg0, arg1, or arg2 if they are date and time values.

  • 自訂IFormatProvider實作,提供格式設定資訊arg0arg1,和arg2A custom IFormatProvider implementation that provides formatting information for arg0, arg1, and arg2. 一般而言,這類實作也會實作ICustomFormatter介面。Typically, such an implementation also implements the ICustomFormatter interface.

如果provider參數是null,格式提供者資訊取自目前文化特性。If the provider parameter is null, format provider information is obtained from the current culture.

arg0``arg1,和arg2表示要格式化的物件。arg0, arg1, and arg2 represent the objects to be formatted. 中的每個格式項目format會取代具有對應的索引之物件的字串表示。Each format item in format is replaced with the string representation of the object that has the corresponding index. 如果格式項目包含formatString並實作相對應的引數IFormattable介面,則該引數的ToString(formatString, provider)方法可讓您定義的格式。If the format item includes formatString and the corresponding argument implements the IFormattable interface, then the argument's ToString(formatString, provider) method defines the formatting. 否則,引數的ToString()方法可讓您定義的格式。Otherwise, the argument's ToString() method defines the formatting.

給呼叫者的注意事項

在.NET Core 和.NET Framework 4.0 和更新版本中,當您具現化StringBuilder藉由呼叫物件StringBuilder(Int32, Int32)建構函式,長度和容量StringBuilder執行個體可以成長的值超過其MaxCapacity屬性。In .NET Core and in the .NET Framework 4.0 and later versions, when you instantiate the StringBuilder object by calling the StringBuilder(Int32, Int32) constructor, both the length and the capacity of the StringBuilder instance can grow beyond the value of its MaxCapacity property. 這可能特別是當您呼叫Append(String)AppendFormat(String, Object)附加小字串的方法。This can occur particularly when you call the Append(String) and AppendFormat(String, Object) methods to append small strings.

另請參閱

AppendFormat(String, Object) AppendFormat(String, Object) AppendFormat(String, Object) AppendFormat(String, Object)

將處理複合格式字串所傳回的字串 (其中包含零或更多的格式項目) 附加至這個執行個體。Appends the string returned by processing a composite format string, which contains zero or more format items, to this instance. 每一個格式項目都會取代為單一引數的字串表示。Each format item is replaced by the string representation of a single argument.

public:
 System::Text::StringBuilder ^ AppendFormat(System::String ^ format, System::Object ^ arg0);
public System.Text.StringBuilder AppendFormat (string format, object arg0);
member this.AppendFormat : string * obj -> System.Text.StringBuilder
Public Function AppendFormat (format As String, arg0 As Object) As StringBuilder

參數

format
String String String String

複合格式字串。A composite format string.

arg0
Object Object Object Object

要格式化的物件。An object to format.

傳回

附加 format 的執行個體參考。A reference to this instance with format appended. format 中的每一個格式項目都會取代為 arg0 的字串表示。Each format item in format is replaced by the string representation of arg0.

例外狀況

format 無效。format is invalid.

-或--or- 格式項目的索引小於 0 (零) 或大於等於 1。The index of a format item is less than 0 (zero), or greater than or equal to 1.

展開後的字串長度會超過 MaxCapacityThe length of the expanded string would exceed MaxCapacity.

範例

下列範例示範AppendFormat方法。The following example demonstrates the AppendFormat method.

using namespace System;
using namespace System::Text;
using namespace System::Globalization;
void Show( StringBuilder^ sbs )
{
   Console::WriteLine( sbs );
   sbs->Length = 0;
}

int main()
{
   StringBuilder^ sb = gcnew StringBuilder;
   int var1 = 111;
   float var2 = 2.22F;
   String^ var3 = "abcd";
   array<Object^>^var4 = {3,4.4,(Char)'X'};
   Console::WriteLine();
   Console::WriteLine( "StringBuilder.AppendFormat method:" );
   sb->AppendFormat( "1) {0}", var1 );
   Show( sb );
   sb->AppendFormat( "2) {0}, {1}", var1, var2 );
   Show( sb );
   sb->AppendFormat( "3) {0}, {1}, {2}", var1, var2, var3 );
   Show( sb );
   sb->AppendFormat( "4) {0}, {1}, {2}", var4 );
   Show( sb );
   CultureInfo^ ci = gcnew CultureInfo( "es-ES",true );
   array<Object^>^temp1 = {var2};
   sb->AppendFormat( ci, "5) {0}", temp1 );
   Show( sb );
}

/*
This example produces the following results:

StringBuilder.AppendFormat method:
1) 111
2) 111, 2.22
3) 111, 2.22, abcd
4) 3, 4.4, X
5) 2,22
*/
using System;
using System.Text;
using System.Globalization;

class Sample 
{
    static StringBuilder sb = new StringBuilder();

    public static void Main() 
    {
    int    var1   = 111;
    float  var2   = 2.22F;
    string var3   = "abcd";
    object[] var4 = {3, 4.4, 'X'};

    Console.WriteLine();
    Console.WriteLine("StringBuilder.AppendFormat method:");
    sb.AppendFormat("1) {0}", var1);
    Show(sb);
    sb.AppendFormat("2) {0}, {1}", var1, var2);
    Show(sb);
    sb.AppendFormat("3) {0}, {1}, {2}", var1, var2, var3);
    Show(sb);
    sb.AppendFormat("4) {0}, {1}, {2}", var4);
    Show(sb);
    CultureInfo ci = new CultureInfo("es-ES", true);
    sb.AppendFormat(ci, "5) {0}", var2);
    Show(sb);
    }

    public static void Show(StringBuilder sbs)
    {
    Console.WriteLine(sbs.ToString());
    sb.Length = 0;
    }
}
/*
This example produces the following results:

StringBuilder.AppendFormat method:
1) 111
2) 111, 2.22
3) 111, 2.22, abcd
4) 3, 4.4, X
5) 2,22
*/
Imports System
Imports System.Text
Imports System.Globalization

Class Sample
   Private Shared sb As New StringBuilder()

   Public Shared Sub Main()
      Dim var1 As Integer = 111
      Dim var2 As Single = 2.22F
      Dim var3 As String = "abcd"
      Dim var4 As Object() =  {3, 4.4, "X"c}
      
      Console.WriteLine()
      Console.WriteLine("StringBuilder.AppendFormat method:")
      sb.AppendFormat("1) {0}", var1)
      Show(sb)
      sb.AppendFormat("2) {0}, {1}", var1, var2)
      Show(sb)
      sb.AppendFormat("3) {0}, {1}, {2}", var1, var2, var3)
      Show(sb)
      sb.AppendFormat("4) {0}, {1}, {2}", var4)
      Show(sb)
      Dim ci As New CultureInfo("es-ES", True)
      sb.AppendFormat(ci, "5) {0}", var2)
      Show(sb)
   End Sub 'Main
   
   Public Shared Sub Show(sbs As StringBuilder)
      Console.WriteLine(sbs.ToString())
      sb.Length = 0
   End Sub 'Show
End Class 'Sample
'
'This example produces the following results:
'
'StringBuilder.AppendFormat method:
'1) 111
'2) 111, 2.22
'3) 111, 2.22, abcd
'4) 3, 4.4, X
'5) 2,22

備註

這個方法會使用複合格式功能物件的值轉換成其文字表示,並將該表示內嵌在目前的.NET frameworkStringBuilder物件。This method uses the composite formatting feature of the .NET Framework to convert the value of an object to its text representation and embed that representation in the current StringBuilder object.

format參數是由零個或多個文字執行混合零或多個索引的預留位置,稱為格式項目。The format parameter consists of zero or more runs of text intermixed with zero or more indexed placeholders, called format items. 格式項目的索引必須是 0,以對應至arg0,這個方法的參數清單中的單一物件。The index of the format items must be 0, to correspond to arg0, the single object in the parameter list of this method. 格式化的程序取代的字串表示法中的每個格式項目arg0The formatting process replaces each format item with the string representation of arg0.

格式項目的語法如下所示:The syntax of a format item is as follows:

{index[,length][:formatString]}{index[,length][:formatString]}

在方括號中的元素是選擇性的元素。Elements in square brackets are optional. 下表說明每個元素。The following table describes each element.

元素Element 描述Description
indexindex 參數清單中要格式化之物件的以零為起始位置。The zero-based position in the parameter list of the object to be formatted. 如果所指定的物件indexnull,格式項目取代為String.EmptyIf the object specified by index is null, the format item is replaced by String.Empty. 如果在沒有參數index位置,FormatException就會擲回。If there is no parameter in the index position, a FormatException is thrown.
,length,length 參數的字串表示法中的字元數目下限。The minimum number of characters in the string representation of the parameter. 如果是正數,參數會靠右對齊;如果是負數,它是靠左對齊。If positive, the parameter is right-aligned; if negative, it is left-aligned.
:formatString:formatString 標準或自訂格式字串所支援的參數。A standard or custom format string that is supported by the parameter.

注意

搭配日期和時間值的標準和自訂格式字串,請參閱 < 標準日期和時間格式字串自訂日期和時間格式字串For the standard and custom format strings used with date and time values, see Standard Date and Time Format Strings and Custom Date and Time Format Strings. 針對搭配數值使用標準和自訂格式字串,請參閱標準數值格式字串自訂數值格式字串For the standard and custom format strings used with numeric values, see Standard Numeric Format Strings and Custom Numeric Format Strings. 列舉型別搭配使用的標準格式字串,請參閱 < 列舉格式字串For the standard format strings used with enumerations, see Enumeration Format Strings.

arg0 表示要格式化的物件。arg0 represents the object to be formatted. 中的每個格式項目format的字串表示取代arg0Each format item in format is replaced with the string representation of arg0. 如果格式項目包含formatStringarg0實作IFormattable介面,然後arg0.ToString(formatString, null)定義的格式。If the format item includes formatString and arg0 implements the IFormattable interface, then arg0.ToString(formatString, null) defines the formatting. 否則,arg0.ToString()定義的格式。Otherwise, arg0.ToString() defines the formatting.

如果字串指派給format是 「 感謝您捐贈 {0: # # #} 罐食物給本慈善組織。 」If the string assigned to format is "Thank you for your donation of {0:####} cans of food to our charitable organization." arg0是一個整數值為 10,傳回的值會是 「 謝謝您捐贈 10 罐食物給本慈善組織。 」and arg0 is an integer with the value 10, the return value will be "Thank you for your donation of 10 cans of food to our charitable organization."

給呼叫者的注意事項

在.NET Core 和.NET Framework 4.0 和更新版本中,當您具現化StringBuilder藉由呼叫物件StringBuilder(Int32, Int32)建構函式,長度和容量StringBuilder執行個體可以成長的值超過其MaxCapacity屬性。In .NET Core and in the .NET Framework 4.0 and later versions, when you instantiate the StringBuilder object by calling the StringBuilder(Int32, Int32) constructor, both the length and the capacity of the StringBuilder instance can grow beyond the value of its MaxCapacity property. 這可能特別是當您呼叫Append(String)AppendFormat(String, Object)附加小字串的方法。This can occur particularly when you call the Append(String) and AppendFormat(String, Object) methods to append small strings.

另請參閱

AppendFormat(String, Object[]) AppendFormat(String, Object[]) AppendFormat(String, Object[]) AppendFormat(String, Object[])

將處理複合格式字串所傳回的字串 (其中包含零或更多的格式項目) 附加至這個執行個體。Appends the string returned by processing a composite format string, which contains zero or more format items, to this instance. 每一個格式項目會由參數陣列中對應之引數的字串表示所取代。Each format item is replaced by the string representation of a corresponding argument in a parameter array.

public:
 System::Text::StringBuilder ^ AppendFormat(System::String ^ format, ... cli::array <System::Object ^> ^ args);
public System.Text.StringBuilder AppendFormat (string format, params object[] args);
member this.AppendFormat : string * obj[] -> System.Text.StringBuilder
Public Function AppendFormat (format As String, ParamArray args As Object()) As StringBuilder

參數

format
String String String String

複合格式字串。A composite format string.

args
Object[]

要格式化的物件陣列。An array of objects to format.

傳回

附加 format 的執行個體參考。A reference to this instance with format appended. format 中的每一個格式項目會由對應之物件引數的字串表示所取代。Each format item in format is replaced by the string representation of the corresponding object argument.

例外狀況

formatargsnullformat or args is null.

format 無效。format is invalid.

-或--or- 格式項目的索引小於 0 (零),或大於或等於 args 陣列的長度。The index of a format item is less than 0 (zero), or greater than or equal to the length of the args array.

展開後的字串長度會超過 MaxCapacityThe length of the expanded string would exceed MaxCapacity.

範例

下列範例示範AppendFormat方法。The following example demonstrates the AppendFormat method.

using namespace System;
using namespace System::Text;
using namespace System::Globalization;
void Show( StringBuilder^ sbs )
{
   Console::WriteLine( sbs );
   sbs->Length = 0;
}

int main()
{
   StringBuilder^ sb = gcnew StringBuilder;
   int var1 = 111;
   float var2 = 2.22F;
   String^ var3 = "abcd";
   array<Object^>^var4 = {3,4.4,(Char)'X'};
   Console::WriteLine();
   Console::WriteLine( "StringBuilder.AppendFormat method:" );
   sb->AppendFormat( "1) {0}", var1 );
   Show( sb );
   sb->AppendFormat( "2) {0}, {1}", var1, var2 );
   Show( sb );
   sb->AppendFormat( "3) {0}, {1}, {2}", var1, var2, var3 );
   Show( sb );
   sb->AppendFormat( "4) {0}, {1}, {2}", var4 );
   Show( sb );
   CultureInfo^ ci = gcnew CultureInfo( "es-ES",true );
   array<Object^>^temp1 = {var2};
   sb->AppendFormat( ci, "5) {0}", temp1 );
   Show( sb );
}

/*
This example produces the following results:

StringBuilder.AppendFormat method:
1) 111
2) 111, 2.22
3) 111, 2.22, abcd
4) 3, 4.4, X
5) 2,22
*/
using System;
using System.Text;
using System.Globalization;

class Sample 
{
    static StringBuilder sb = new StringBuilder();

    public static void Main() 
    {
    int    var1   = 111;
    float  var2   = 2.22F;
    string var3   = "abcd";
    object[] var4 = {3, 4.4, 'X'};

    Console.WriteLine();
    Console.WriteLine("StringBuilder.AppendFormat method:");
    sb.AppendFormat("1) {0}", var1);
    Show(sb);
    sb.AppendFormat("2) {0}, {1}", var1, var2);
    Show(sb);
    sb.AppendFormat("3) {0}, {1}, {2}", var1, var2, var3);
    Show(sb);
    sb.AppendFormat("4) {0}, {1}, {2}", var4);
    Show(sb);
    CultureInfo ci = new CultureInfo("es-ES", true);
    sb.AppendFormat(ci, "5) {0}", var2);
    Show(sb);
    }

    public static void Show(StringBuilder sbs)
    {
    Console.WriteLine(sbs.ToString());
    sb.Length = 0;
    }
}
/*
This example produces the following results:

StringBuilder.AppendFormat method:
1) 111
2) 111, 2.22
3) 111, 2.22, abcd
4) 3, 4.4, X
5) 2,22
*/
Imports System
Imports System.Text
Imports System.Globalization

Class Sample
   Private Shared sb As New StringBuilder()

   Public Shared Sub Main()
      Dim var1 As Integer = 111
      Dim var2 As Single = 2.22F
      Dim var3 As String = "abcd"
      Dim var4 As Object() =  {3, 4.4, "X"c}
      
      Console.WriteLine()
      Console.WriteLine("StringBuilder.AppendFormat method:")
      sb.AppendFormat("1) {0}", var1)
      Show(sb)
      sb.AppendFormat("2) {0}, {1}", var1, var2)
      Show(sb)
      sb.AppendFormat("3) {0}, {1}, {2}", var1, var2, var3)
      Show(sb)
      sb.AppendFormat("4) {0}, {1}, {2}", var4)
      Show(sb)
      Dim ci As New CultureInfo("es-ES", True)
      sb.AppendFormat(ci, "5) {0}", var2)
      Show(sb)
   End Sub 'Main
   
   Public Shared Sub Show(sbs As StringBuilder)
      Console.WriteLine(sbs.ToString())
      sb.Length = 0
   End Sub 'Show
End Class 'Sample
'
'This example produces the following results:
'
'StringBuilder.AppendFormat method:
'1) 111
'2) 111, 2.22
'3) 111, 2.22, abcd
'4) 3, 4.4, X
'5) 2,22

備註

這個方法會使用複合格式功能物件的值轉換成其文字表示,並將該表示內嵌在目前的.NET frameworkStringBuilder物件。This method uses the composite formatting feature of the .NET Framework to convert the value of an object to its text representation and embed that representation in the current StringBuilder object.

format參數是由零個或多個文字執行混合零或多個索引的預留位置,稱為格式項目,對應至這個方法的參數清單中的物件。The format parameter consists of zero or more runs of text intermixed with zero or more indexed placeholders, called format items, that correspond to objects in the parameter list of this method. 格式化的程序會將每個格式項目取代對應的物件的字串表示。The formatting process replaces each format item with the string representation of the corresponding object.

格式項目的語法如下所示:The syntax of a format item is as follows:

{index[,length][:formatString]}{index[,length][:formatString]}

在方括號中的元素是選擇性的元素。Elements in square brackets are optional. 下表說明每個元素。The following table describes each element.

元素Element 描述Description
indexindex 參數清單中要格式化之物件的以零為起始位置。The zero-based position in the parameter list of the object to be formatted. 如果所指定的物件indexnull,格式項目取代為String.EmptyIf the object specified by index is null, the format item is replaced by String.Empty. 如果在沒有參數index位置,FormatException就會擲回。If there is no parameter in the index position, a FormatException is thrown.
,length,length 參數的字串表示法中的字元數目下限。The minimum number of characters in the string representation of the parameter. 如果是正數,參數會靠右對齊;如果是負數,它是靠左對齊。If positive, the parameter is right-aligned; if negative, it is left-aligned.
:formatString:formatString 標準或自訂格式字串所支援的參數。A standard or custom format string that is supported by the parameter.

注意

搭配日期和時間值的標準和自訂格式字串,請參閱 < 標準日期和時間格式字串自訂日期和時間格式字串For the standard and custom format strings used with date and time values, see Standard Date and Time Format Strings and Custom Date and Time Format Strings. 針對搭配數值使用標準和自訂格式字串,請參閱標準數值格式字串自訂數值格式字串For the standard and custom format strings used with numeric values, see Standard Numeric Format Strings and Custom Numeric Format Strings. 列舉型別搭配使用的標準格式字串,請參閱 < 列舉格式字串For the standard format strings used with enumerations, see Enumeration Format Strings.

args 表示要格式化的物件。args represents the objects to be formatted. 中的每個格式項目format中的對應物件的字串表示取代argsEach format item in format is replaced with the string representation of the corresponding object in args. 如果格式項目包含formatString中對應的物件args實作IFormattable介面,然後args[index].ToString(formatString, provider)定義的格式。If the format item includes formatString and the corresponding object in args implements the IFormattable interface, then args[index].ToString(formatString, provider) defines the formatting. 否則,args[index].ToString()定義的格式。Otherwise, args[index].ToString() defines the formatting.

如果字串指派給format是 「 感謝您捐贈 {0: # # #} 罐食物給本慈善組織。 」If the string assigned to format is "Thank you for your donation of {0:####} cans of food to our charitable organization." arg0是一個整數值為 10,傳回的值會是 「 謝謝您捐贈 10 罐食物給本慈善組織。 」and arg0 is an integer with the value 10, the return value will be "Thank you for your donation of 10 cans of food to our charitable organization."

給呼叫者的注意事項

在.NET Core 和.NET Framework 4.0 和更新版本中,當您具現化StringBuilder藉由呼叫物件StringBuilder(Int32, Int32)建構函式,長度和容量StringBuilder執行個體可以成長的值超過其MaxCapacity屬性。In .NET Core and in the .NET Framework 4.0 and later versions, when you instantiate the StringBuilder object by calling the StringBuilder(Int32, Int32) constructor, both the length and the capacity of the StringBuilder instance can grow beyond the value of its MaxCapacity property. 這可能特別是當您呼叫Append(String)AppendFormat(String, Object)附加小字串的方法。This can occur particularly when you call the Append(String) and AppendFormat(String, Object) methods to append small strings.

另請參閱

AppendFormat(IFormatProvider, String, Object) AppendFormat(IFormatProvider, String, Object) AppendFormat(IFormatProvider, String, Object) AppendFormat(IFormatProvider, String, Object)

將處理複合格式字串所傳回的字串 (其中包含零或更多的格式項目) 附加至這個執行個體。Appends the string returned by processing a composite format string, which contains zero or more format items, to this instance. 使用指定的格式提供者,將每個格式項目取代為單一引數的字串表示。Each format item is replaced by the string representation of a single argument using a specified format provider.

public:
 System::Text::StringBuilder ^ AppendFormat(IFormatProvider ^ provider, System::String ^ format, System::Object ^ arg0);
public System.Text.StringBuilder AppendFormat (IFormatProvider provider, string format, object arg0);
member this.AppendFormat : IFormatProvider * string * obj -> System.Text.StringBuilder
Public Function AppendFormat (provider As IFormatProvider, format As String, arg0 As Object) As StringBuilder

參數

provider
IFormatProvider IFormatProvider IFormatProvider IFormatProvider

物件,提供特定文化特性格式資訊。An object that supplies culture-specific formatting information.

format
String String String String

複合格式字串。A composite format string.

arg0
Object Object Object Object

要格式化的物件。The object to format.

傳回

完成附加作業之後,這個執行個體的參考。A reference to this instance after the append operation has completed. 在附加作業之後,這個執行個體會包含作業前已經存在的所有資料,並後置有 format 的複本,其中的任何格式規格都會由 arg0 的字串表示所取代。After the append operation, this instance contains any data that existed before the operation, suffixed by a copy of format in which any format specification is replaced by the string representation of arg0.

例外狀況

format 無效。format is invalid.

-或--or- 格式項目的索引小於 0 (零) 或大於等於 1。The index of a format item is less than 0 (zero), or greater than or equal to one (1).

展開後的字串長度會超過 MaxCapacityThe length of the expanded string would exceed MaxCapacity.

範例

以下包含兩個呼叫AppendFormat(IFormatProvider, String, Object)方法。The following includes two calls to the AppendFormat(IFormatProvider, String, Object) method. 兩者都使用英文-英國 (EN-GB) 文化特性的格式化慣例。Both use the formatting conventions of the English-Great Britain (en-GB) culture. 第一個插入的字串表示Decimal值結果字串中的貨幣。The first inserts the string representation of a Decimal value currency in a result string. 第二個插入DateTime字串在結果中的兩個位置的值,第一個包括僅限簡短日期字串和第二個短時間的字串。The second inserts a DateTime value in two places in a result string, the first including only the short date string and the second the short time string.

using System;
using System.Globalization;
using System.Text;

public class Example
{
   public static void Main()
   {
      StringBuilder sb = new StringBuilder();
      Decimal value = 16.95m;
      CultureInfo enGB = CultureInfo.CreateSpecificCulture("en-GB");
      DateTime dateToday = DateTime.Now;
      sb.AppendFormat(enGB, "Final Price: {0:C2}", value);
      sb.AppendLine();
      sb.AppendFormat(enGB, "Date and Time: {0:d} at {0:t}", dateToday);
      Console.WriteLine(sb.ToString());
   }
}
// The example displays the following output:
//       Final Price: £16.95
//       Date and Time: 01/10/2014 at 10:22
Imports System.Globalization
Imports System.Text

Module Example
   Public Sub Main()
      Dim sb As New StringBuilder()
      Dim value As Decimal = 16.95d
      Dim enGB As CultureInfo = CultureInfo.CreateSpecificCulture("en-GB")
      Dim dateToday As DateTime = Date.Now
      sb.AppendFormat(enGB, "Final Price: {0:C2}", value)
      sb.AppendLine()
      sb.AppendFormat(enGB, "Date and Time: {0:d} at {0:t}", dateToday)
      Console.WriteLine(sb.ToString())
   End Sub
End Module
' The example displays output like the following:
'       Final Price: £16.95
'       Date and Time: 01/10/2014 at 10:22

備註

這個方法會使用複合格式功能的.NET Framework,才能將值轉換成arg0成其文字表示,而且在目前嵌入該表示法StringBuilder物件。This method uses the composite formatting feature of the .NET Framework to convert the value of arg0 to its text representation and embed that representation in the current StringBuilder object.

format參數是由零個或多個文字執行混合零或多個索引的預留位置,稱為格式項目。The format parameter consists of zero or more runs of text intermixed with zero or more indexed placeholders, called format items. 每個格式項目的索引必須是零 (0),因為這個方法包含使用單一引數的引數清單。The index of each format item must be zero (0) since this method includes an argument list with a single argument. 格式化的程序取代的字串表示法中的每個格式項目arg0The formatting process replaces each format item with the string representation of arg0.

格式項目的語法如下所示:The syntax of a format item is as follows:

{index[,length][:formatString]}{index[,length][:formatString]}

在方括號中的元素是選擇性的元素。Elements in square brackets are optional. 下表說明每個元素。The following table describes each element.

元素Element 描述Description
indexindex 參數清單中要格式化之物件的以零為起始位置。The zero-based position in the parameter list of the object to be formatted. 如果所指定的物件indexnull,格式項目取代為String.EmptyIf the object specified by index is null, the format item is replaced by String.Empty. 在此情況下,因為AppendFormat(IFormatProvider, String, Object)方法中引數清單的值具有單一引數index必須一律為 0。In this case, since the AppendFormat(IFormatProvider, String, Object) method has a single argument in the argument list, the value of index must always be 0. 如果未列出,請FormatException就會擲回。If it is not, a FormatException is thrown.
,length,length 參數的字串表示法中的字元數目下限。The minimum number of characters in the string representation of the parameter. 如果是正數,參數會靠右對齊;如果是負數,它是靠左對齊。If positive, the parameter is right-aligned; if negative, it is left-aligned.
:formatString:formatString 標準或自訂格式字串所支援的參數。A standard or custom format string that is supported by the parameter.

注意

搭配日期和時間值的標準和自訂格式字串,請參閱 < 標準日期和時間格式字串自訂日期和時間格式字串For the standard and custom format strings used with date and time values, see Standard Date and Time Format Strings and Custom Date and Time Format Strings. 針對搭配數值使用標準和自訂格式字串,請參閱標準數值格式字串自訂數值格式字串For the standard and custom format strings used with numeric values, see Standard Numeric Format Strings and Custom Numeric Format Strings. 列舉型別搭配使用的標準格式字串,請參閱 < 列舉格式字串For the standard format strings used with enumerations, see Enumeration Format Strings.

provider參數指定IFormatProvider實作,可提供格式設定資訊中的物件argsThe provider parameter specifies an IFormatProvider implementation that can provide formatting information for the objects in args. provider 可以是下列任何項目:provider can be any of the following:

  • ACultureInfo提供特定文化特性格式資訊的物件。A CultureInfo object that provides culture-specific formatting information.

  • ANumberFormatInfo物件,提供特定文化特性格式資訊arg0如果它是一個數字值。A NumberFormatInfo object that provides culture-specific formatting information for arg0 if it is a numeric value.

  • ADateTimeFormatInfo物件,提供特定文化特性格式資訊arg0時的日期和時間值。A DateTimeFormatInfo object that provides culture-specific formatting information for arg0 if it is a date and time value.

  • 自訂IFormatProvider實作,提供格式設定資訊arg0A custom IFormatProvider implementation that provides formatting information for arg0. 一般而言,這類實作也會實作ICustomFormatter介面。Typically, such an implementation also implements the ICustomFormatter interface.

如果provider參數是null、 格式資訊取自目前文化特性。If the provider parameter is null, formatting information is obtained from the current culture.

arg0 表示要格式化的物件。arg0 represents the object to be formatted. 中的每個格式項目format的字串表示取代arg0Each format item in format is replaced with the string representation of arg0. 如果格式項目包含formatStringarg0實作IFormattable介面,然後arg0.ToString(formatString, provider)定義的格式。If the format item includes formatString and arg0 implements the IFormattable interface, then arg0.ToString(formatString, provider) defines the formatting. 否則,arg0.ToString()定義的格式。Otherwise, arg0.ToString() defines the formatting.

給呼叫者的注意事項

在.NET Core 和.NET Framework 4.0 和更新版本中,當您具現化StringBuilder藉由呼叫物件StringBuilder(Int32, Int32)建構函式,長度和容量StringBuilder執行個體可以成長的值超過其MaxCapacity屬性。In .NET Core and in the .NET Framework 4.0 and later versions, when you instantiate the StringBuilder object by calling the StringBuilder(Int32, Int32) constructor, both the length and the capacity of the StringBuilder instance can grow beyond the value of its MaxCapacity property. 這可能特別是當您呼叫Append(String)AppendFormat(String, Object)附加小字串的方法。This can occur particularly when you call the Append(String) and AppendFormat(String, Object) methods to append small strings.

另請參閱

AppendFormat(IFormatProvider, String, Object[]) AppendFormat(IFormatProvider, String, Object[]) AppendFormat(IFormatProvider, String, Object[]) AppendFormat(IFormatProvider, String, Object[])

將處理複合格式字串所傳回的字串 (其中包含零或更多的格式項目) 附加至這個執行個體。Appends the string returned by processing a composite format string, which contains zero or more format items, to this instance. 每一個格式項目會由參數陣列 (此參數陣列使用所指定的格式提供者) 中對應之物件引數的字串表示所取代。Each format item is replaced by the string representation of a corresponding argument in a parameter array using a specified format provider.

public:
 System::Text::StringBuilder ^ AppendFormat(IFormatProvider ^ provider, System::String ^ format, ... cli::array <System::Object ^> ^ args);
public System.Text.StringBuilder AppendFormat (IFormatProvider provider, string format, params object[] args);
member this.AppendFormat : IFormatProvider * string * obj[] -> System.Text.StringBuilder
Public Function AppendFormat (provider As IFormatProvider, format As String, ParamArray args As Object()) As StringBuilder

參數

provider
IFormatProvider IFormatProvider IFormatProvider IFormatProvider

物件,提供特定文化特性格式資訊。An object that supplies culture-specific formatting information.

format
String String String String

複合格式字串。A composite format string.

args
Object[]

要格式化的物件陣列。An array of objects to format.

傳回

完成附加作業之後,這個執行個體的參考。A reference to this instance after the append operation has completed. 在附加作業之後,此執行個體會包含此作業之前已存在的所有資料,並後置有 format 的複本,其中的任何格式規格都會由對應物件引數的字串表示所取代。After the append operation, this instance contains any data that existed before the operation, suffixed by a copy of format where any format specification is replaced by the string representation of the corresponding object argument.

例外狀況

format 無效。format is invalid.

-或--or- 格式項目的索引小於 0 (零),或大於或等於 args 陣列的長度。The index of a format item is less than 0 (zero), or greater than or equal to the length of the args array.

展開後的字串長度會超過 MaxCapacityThe length of the expanded string would exceed MaxCapacity.

範例

下列範例示範AppendFormat方法。The following example demonstrates the AppendFormat method.

using namespace System;
using namespace System::Text;
using namespace System::Globalization;
void Show( StringBuilder^ sbs )
{
   Console::WriteLine( sbs );
   sbs->Length = 0;
}

int main()
{
   StringBuilder^ sb = gcnew StringBuilder;
   int var1 = 111;
   float var2 = 2.22F;
   String^ var3 = "abcd";
   array<Object^>^var4 = {3,4.4,(Char)'X'};
   Console::WriteLine();
   Console::WriteLine( "StringBuilder.AppendFormat method:" );
   sb->AppendFormat( "1) {0}", var1 );
   Show( sb );
   sb->AppendFormat( "2) {0}, {1}", var1, var2 );
   Show( sb );
   sb->AppendFormat( "3) {0}, {1}, {2}", var1, var2, var3 );
   Show( sb );
   sb->AppendFormat( "4) {0}, {1}, {2}", var4 );
   Show( sb );
   CultureInfo^ ci = gcnew CultureInfo( "es-ES",true );
   array<Object^>^temp1 = {var2};
   sb->AppendFormat( ci, "5) {0}", temp1 );
   Show( sb );
}

/*
This example produces the following results:

StringBuilder.AppendFormat method:
1) 111
2) 111, 2.22
3) 111, 2.22, abcd
4) 3, 4.4, X
5) 2,22
*/
using System;
using System.Text;
using System.Globalization;

class Sample 
{
    static StringBuilder sb = new StringBuilder();

    public static void Main() 
    {
    int    var1   = 111;
    float  var2   = 2.22F;
    string var3   = "abcd";
    object[] var4 = {3, 4.4, 'X'};

    Console.WriteLine();
    Console.WriteLine("StringBuilder.AppendFormat method:");
    sb.AppendFormat("1) {0}", var1);
    Show(sb);
    sb.AppendFormat("2) {0}, {1}", var1, var2);
    Show(sb);
    sb.AppendFormat("3) {0}, {1}, {2}", var1, var2, var3);
    Show(sb);
    sb.AppendFormat("4) {0}, {1}, {2}", var4);
    Show(sb);
    CultureInfo ci = new CultureInfo("es-ES", true);
    sb.AppendFormat(ci, "5) {0}", var2);
    Show(sb);
    }

    public static void Show(StringBuilder sbs)
    {
    Console.WriteLine(sbs.ToString());
    sb.Length = 0;
    }
}
/*
This example produces the following results:

StringBuilder.AppendFormat method:
1) 111
2) 111, 2.22
3) 111, 2.22, abcd
4) 3, 4.4, X
5) 2,22
*/
Imports System
Imports System.Text
Imports System.Globalization

Class Sample
   Private Shared sb As New StringBuilder()

   Public Shared Sub Main()
      Dim var1 As Integer = 111
      Dim var2 As Single = 2.22F
      Dim var3 As String = "abcd"
      Dim var4 As Object() =  {3, 4.4, "X"c}
      
      Console.WriteLine()
      Console.WriteLine("StringBuilder.AppendFormat method:")
      sb.AppendFormat("1) {0}", var1)
      Show(sb)
      sb.AppendFormat("2) {0}, {1}", var1, var2)
      Show(sb)
      sb.AppendFormat("3) {0}, {1}, {2}", var1, var2, var3)
      Show(sb)
      sb.AppendFormat("4) {0}, {1}, {2}", var4)
      Show(sb)
      Dim ci As New CultureInfo("es-ES", True)
      sb.AppendFormat(ci, "5) {0}", var2)
      Show(sb)
   End Sub 'Main
   
   Public Shared Sub Show(sbs As StringBuilder)
      Console.WriteLine(sbs.ToString())
      sb.Length = 0
   End Sub 'Show
End Class 'Sample
'
'This example produces the following results:
'
'StringBuilder.AppendFormat method:
'1) 111
'2) 111, 2.22
'3) 111, 2.22, abcd
'4) 3, 4.4, X
'5) 2,22

下列範例會定義自訂IFormatProvider實作名為CustomerFormatter格式化 10 位數客戶編號,以連字號之後的第四個和第七個位數。The following example defines a custom IFormatProvider implementation named CustomerFormatter that formats a 10-digit customer number with hyphens after the fourth and seventh digits. 它會傳遞至StringBuilder.AppendFormat(IFormatProvider, String, Object[])方法用來建立包含已格式化的客戶數目和客戶名稱的字串。It is passed to the StringBuilder.AppendFormat(IFormatProvider, String, Object[]) method to create a string that includes the formatted customer number and customer name.

using System;
using System.Text;

public class Customer
{
   private string custName;
   private int custNumber;
   
   public Customer(string name, int number)
   {
      this.custName = name;
      this.custNumber = number;
   }
   
   public string Name
   {
      get { return this.custName; }
   }
   
   public int CustomerNumber
   {
      get { return this.custNumber; }
   }
}

public class CustomerNumberFormatter : IFormatProvider, ICustomFormatter
{   
   public object GetFormat(Type formatType)
   {
      if (formatType == typeof(ICustomFormatter))
         return this;
      return null;
   }
   
   public string Format(string format, object arg, IFormatProvider provider)
   {
      if (arg is Int32)
      {
         string custNumber = ((int) arg).ToString("D10");
         return custNumber.Substring(0, 4) + "-" + custNumber.Substring(4, 3) + 
                "-" + custNumber.Substring(7, 3);
      }
      else
      {
         return null;
      }
   }                   
}

public class Example
{
   public static void Main()
   {
      Customer customer = new Customer("A Plus Software", 903654);
      StringBuilder sb = new StringBuilder();
      sb.AppendFormat(new CustomerNumberFormatter(), "{0}: {1}", 
                      customer.CustomerNumber, customer.Name);
      Console.WriteLine(sb.ToString());
   }
}
// The example displays the following output:
//      0000-903-654: A Plus Software
Imports System.Text

Public Class Customer
   Private custName As String
   Private custNumber As Integer
   
   Public Sub New(name As String, number As Integer)
      custName = name
      custNumber = number
   End Sub
   
   Public ReadOnly Property Name As String
      Get
         Return Me.custName
      End Get
   End Property
   
   Public ReadOnly Property CustomerNumber As Integer
      Get
         Return Me.custNumber
      End Get
   End Property
End Class

Public Class CustomerNumberFormatter 
   Implements IFormatProvider, ICustomFormatter
   
   Public Function GetFormat(formatType As Type) As Object _
                   Implements IFormatProvider.GetFormat
      If formatType Is GetType(ICustomFormatter) Then
         Return Me
      End If
      Return Nothing
   End Function
   
   Public Function Format(fmt As String, arg As Object, provider As IFormatProvider) As String _
                   Implements ICustomFormatter.Format
      If typeof arg Is Int32 Then
         Dim custNumber As String = CInt(arg).ToString("D10")
         Return custNumber.Substring(0, 4) + "-" + custNumber.SubString(4, 3) + _
                "-" + custNumber.Substring(7, 3)
      Else
         Return Nothing
      End If
   End Function                   
End Class

Module Example
   Public Sub Main()
      Dim customer As New Customer("A Plus Software", 903654)
      Dim sb As New StringBuilder()
      sb.AppendFormat(New CustomerNumberFormatter, "{0}: {1}", _
                      customer.CustomerNumber, customer.Name)
      Console.WriteLine(sb.ToString())
   End Sub
End Module
' The example displays the following output:
'      0000-903-654: A Plus Software

備註

這個方法會使用複合格式功能物件的值轉換成其文字表示,並將該表示內嵌在目前的.NET frameworkStringBuilder物件。This method uses the composite formatting feature of the .NET Framework to convert the value of an object to its text representation and embed that representation in the current StringBuilder object.

format參數是由零個或多個文字執行混合零或多個索引的預留位置,稱為格式項目,對應至這個方法的參數清單中的物件。The format parameter consists of zero or more runs of text intermixed with zero or more indexed placeholders, called format items, that correspond to objects in the parameter list of this method. 格式化的程序會將每個格式項目取代對應的物件的字串表示。The formatting process replaces each format item with the string representation of the corresponding object.

格式項目的語法如下所示:The syntax of a format item is as follows:

{index[,length][:formatString]}{index[,length][:formatString]}

在方括號中的元素是選擇性的元素。Elements in square brackets are optional. 下表說明每個元素。The following table describes each element.

元素Element 說明Description
indexindex 參數清單中要格式化之物件的以零為起始位置。The zero-based position in the parameter list of the object to be formatted. 如果所指定的物件indexnull,格式項目取代為String.EmptyIf the object specified by index is null, the format item is replaced by String.Empty. 如果在沒有參數index位置,FormatException就會擲回。If there is no parameter in the index position, a FormatException is thrown.
,length,length 參數的字串表示法中的字元數目下限。The minimum number of characters in the string representation of the parameter. 如果是正數,參數會靠右對齊;如果是負數,它是靠左對齊。If positive, the parameter is right-aligned; if negative, it is left-aligned.
:formatString:formatString 標準或自訂格式字串所支援的參數。A standard or custom format string that is supported by the parameter.

注意

搭配日期和時間值的標準和自訂格式字串,請參閱 < 標準日期和時間格式字串自訂日期和時間格式字串For the standard and custom format strings used with date and time values, see Standard Date and Time Format Strings and Custom Date and Time Format Strings. 針對搭配數值使用標準和自訂格式字串,請參閱標準數值格式字串自訂數值格式字串For the standard and custom format strings used with numeric values, see Standard Numeric Format Strings and Custom Numeric Format Strings. 列舉型別搭配使用的標準格式字串,請參閱 < 列舉格式字串For the standard format strings used with enumerations, see Enumeration Format Strings.

provider參數指定IFormatProvider實作,可提供格式設定資訊中的物件argsThe provider parameter specifies an IFormatProvider implementation that can provide formatting information for the objects in args. provider 可以是下列任何項目:provider can be any of the following:

如果provider參數是null,格式提供者資訊取自目前文化特性。If the provider parameter is null, format provider information is obtained from the current culture.

args 表示要格式化的物件。args represents the objects to be formatted. 中的每個格式項目format中的對應物件的字串表示取代argsEach format item in format is replaced with the string representation of the corresponding object in args. 如果格式項目包含formatString中對應的物件args實作IFormattable介面,然後args[index].ToString(formatString, provider)定義的格式。If the format item includes formatString and the corresponding object in args implements the IFormattable interface, then args[index].ToString(formatString, provider) defines the formatting. 否則,args[index].ToString()定義的格式。Otherwise, args[index].ToString() defines the formatting.

給呼叫者的注意事項

在.NET Core 和.NET Framework 4.0 和更新版本中,當您具現化StringBuilder藉由呼叫物件StringBuilder(Int32, Int32)建構函式,長度和容量StringBuilder執行個體可以成長的值超過其MaxCapacity屬性。In .NET Core and in the .NET Framework 4.0 and later versions, when you instantiate the StringBuilder object by calling the StringBuilder(Int32, Int32) constructor, both the length and the capacity of the StringBuilder instance can grow beyond the value of its MaxCapacity property. 這可能特別是當您呼叫Append(String)AppendFormat(String, Object)附加小字串的方法。This can occur particularly when you call the Append(String) and AppendFormat(String, Object) methods to append small strings.

另請參閱

AppendFormat(String, Object, Object) AppendFormat(String, Object, Object) AppendFormat(String, Object, Object) AppendFormat(String, Object, Object)

將處理複合格式字串所傳回的字串 (其中包含零或更多的格式項目) 附加至這個執行個體。Appends the string returned by processing a composite format string, which contains zero or more format items, to this instance. 每一個格式項目都會取代為兩個引數中任一個的字串表示。Each format item is replaced by the string representation of either of two arguments.

public:
 System::Text::StringBuilder ^ AppendFormat(System::String ^ format, System::Object ^ arg0, System::Object ^ arg1);
public System.Text.StringBuilder AppendFormat (string format, object arg0, object arg1);
member this.AppendFormat : string * obj * obj -> System.Text.StringBuilder
Public Function AppendFormat (format As String, arg0 As Object, arg1 As Object) As StringBuilder

參數

format
String String String String

複合格式字串。A composite format string.

arg0
Object Object Object Object

要格式化的第一個物件。The first object to format.

arg1
Object Object Object Object

要格式化的第二個物件。The second object to format.

傳回

附加 format 的執行個體參考。A reference to this instance with format appended. format 中的每一個格式項目會由對應之物件引數的字串表示所取代。Each format item in format is replaced by the string representation of the corresponding object argument.

例外狀況

format 無效。format is invalid.

-或--or- 格式項目的索引小於 0 (零) 或大於等於 2。The index of a format item is less than 0 (zero), or greater than or equal to 2.

展開後的字串長度會超過 MaxCapacityThe length of the expanded string would exceed MaxCapacity.

範例

下列範例示範AppendFormat方法。The following example demonstrates the AppendFormat method.

using namespace System;
using namespace System::Text;
using namespace System::Globalization;
void Show( StringBuilder^ sbs )
{
   Console::WriteLine( sbs );
   sbs->Length = 0;
}

int main()
{
   StringBuilder^ sb = gcnew StringBuilder;
   int var1 = 111;
   float var2 = 2.22F;
   String^ var3 = "abcd";
   array<Object^>^var4 = {3,4.4,(Char)'X'};
   Console::WriteLine();
   Console::WriteLine( "StringBuilder.AppendFormat method:" );
   sb->AppendFormat( "1) {0}", var1 );
   Show( sb );
   sb->AppendFormat( "2) {0}, {1}", var1, var2 );
   Show( sb );
   sb->AppendFormat( "3) {0}, {1}, {2}", var1, var2, var3 );
   Show( sb );
   sb->AppendFormat( "4) {0}, {1}, {2}", var4 );
   Show( sb );
   CultureInfo^ ci = gcnew CultureInfo( "es-ES",true );
   array<Object^>^temp1 = {var2};
   sb->AppendFormat( ci, "5) {0}", temp1 );
   Show( sb );
}

/*
This example produces the following results:

StringBuilder.AppendFormat method:
1) 111
2) 111, 2.22
3) 111, 2.22, abcd
4) 3, 4.4, X
5) 2,22
*/
using System;
using System.Text;
using System.Globalization;

class Sample 
{
    static StringBuilder sb = new StringBuilder();

    public static void Main() 
    {
    int    var1   = 111;
    float  var2   = 2.22F;
    string var3   = "abcd";
    object[] var4 = {3, 4.4, 'X'};

    Console.WriteLine();
    Console.WriteLine("StringBuilder.AppendFormat method:");
    sb.AppendFormat("1) {0}", var1);
    Show(sb);
    sb.AppendFormat("2) {0}, {1}", var1, var2);
    Show(sb);
    sb.AppendFormat("3) {0}, {1}, {2}", var1, var2, var3);
    Show(sb);
    sb.AppendFormat("4) {0}, {1}, {2}", var4);
    Show(sb);
    CultureInfo ci = new CultureInfo("es-ES", true);
    sb.AppendFormat(ci, "5) {0}", var2);
    Show(sb);
    }

    public static void Show(StringBuilder sbs)
    {
    Console.WriteLine(sbs.ToString());
    sb.Length = 0;
    }
}
/*
This example produces the following results:

StringBuilder.AppendFormat method:
1) 111
2) 111, 2.22
3) 111, 2.22, abcd
4) 3, 4.4, X
5) 2,22
*/
Imports System
Imports System.Text
Imports System.Globalization

Class Sample
   Private Shared sb As New StringBuilder()

   Public Shared Sub Main()
      Dim var1 As Integer = 111
      Dim var2 As Single = 2.22F
      Dim var3 As String = "abcd"
      Dim var4 As Object() =  {3, 4.4, "X"c}
      
      Console.WriteLine()
      Console.WriteLine("StringBuilder.AppendFormat method:")
      sb.AppendFormat("1) {0}", var1)
      Show(sb)
      sb.AppendFormat("2) {0}, {1}", var1, var2)
      Show(sb)
      sb.AppendFormat("3) {0}, {1}, {2}", var1, var2, var3)
      Show(sb)
      sb.AppendFormat("4) {0}, {1}, {2}", var4)
      Show(sb)
      Dim ci As New CultureInfo("es-ES", True)
      sb.AppendFormat(ci, "5) {0}", var2)
      Show(sb)
   End Sub 'Main
   
   Public Shared Sub Show(sbs As StringBuilder)
      Console.WriteLine(sbs.ToString())
      sb.Length = 0
   End Sub 'Show
End Class 'Sample
'
'This example produces the following results:
'
'StringBuilder.AppendFormat method:
'1) 111
'2) 111, 2.22
'3) 111, 2.22, abcd
'4) 3, 4.4, X
'5) 2,22

備註

這個方法會使用複合格式功能物件的值轉換成其文字表示,並將該表示內嵌在目前的.NET frameworkStringBuilder物件。This method uses the composite formatting feature of the .NET Framework to convert the value of an object to its text representation and embed that representation in the current StringBuilder object.

format參數是由零個或多個文字執行混合零或多個索引的預留位置,稱為格式項目,對應至arg0arg1,這個方法的參數清單中的兩個物件。The format parameter consists of zero or more runs of text intermixed with zero or more indexed placeholders, called format items, that correspond to arg0 and arg1, the two objects in the parameter list of this method. 格式化的程序會將每個格式項目取代對應的物件的字串表示。The formatting process replaces each format item with the string representation of the corresponding object.

格式項目的語法如下所示:The syntax of a format item is as follows:

{index[,length][:formatString]}{index[,length][:formatString]}

在方括號中的元素是選擇性的元素。Elements in square brackets are optional. 下表說明每個元素。The following table describes each element.

元素Element 描述Description
indexindex 參數清單中要格式化之物件的以零為起始位置。The zero-based position in the parameter list of the object to be formatted. 如果所指定的物件indexnull,格式項目取代為String.EmptyIf the object specified by index is null, the format item is replaced by String.Empty. 如果在沒有參數index位置,FormatException就會擲回。If there is no parameter in the index position, a FormatException is thrown.
,length,length 參數的字串表示法中的字元數目下限。The minimum number of characters in the string representation of the parameter. 如果是正數,參數會靠右對齊;如果是負數,它是靠左對齊。If positive, the parameter is right-aligned; if negative, it is left-aligned.
:formatString:formatString 標準或自訂格式字串所支援的參數。A standard or custom format string that is supported by the parameter.

注意

搭配日期和時間值的標準和自訂格式字串,請參閱 < 標準日期和時間格式字串自訂日期和時間格式字串For the standard and custom format strings used with date and time values, see Standard Date and Time Format Strings and Custom Date and Time Format Strings. 針對搭配數值使用標準和自訂格式字串,請參閱標準數值格式字串自訂數值格式字串For the standard and custom format strings used with numeric values, see Standard Numeric Format Strings and Custom Numeric Format Strings. 列舉型別搭配使用的標準格式字串,請參閱 < 列舉格式字串For the standard format strings used with enumerations, see Enumeration Format Strings.

arg0arg1表示要格式化的物件。arg0 and arg1 represent the objects to be formatted. 中的每個格式項目format任一個的字串表示取代arg0arg1Each format item in format is replaced with the string representation of either arg0 or arg1. 如果格式項目包含formatString和對應的物件會實作IFormattable介面,然後arg x .ToString(formatString, provider)會定義格式,其中x是引數的索引。If the format item includes formatString and the corresponding object implements the IFormattable interface, then argx.ToString(formatString, provider) defines the formatting, where x is the index of the argument. 否則,請arg x .ToString()定義的格式。Otherwise, argx.ToString() defines the formatting.

如果字串指派給format是 「 感謝您捐贈 {0: # # #} 罐食物給本慈善組織。 」If the string assigned to format is "Thank you for your donation of {0:####} cans of food to our charitable organization." arg0是一個整數值為 10,傳回的值會是 「 謝謝您捐贈 10 罐食物給本慈善組織。 」and arg0 is an integer with the value 10, the return value will be "Thank you for your donation of 10 cans of food to our charitable organization."

給呼叫者的注意事項

在.NET Core 和.NET Framework 4.0 和更新版本中,當您具現化StringBuilder藉由呼叫物件StringBuilder(Int32, Int32)建構函式,長度和容量StringBuilder執行個體可以成長的值超過其MaxCapacity屬性。In .NET Core and in the .NET Framework 4.0 and later versions, when you instantiate the StringBuilder object by calling the StringBuilder(Int32, Int32) constructor, both the length and the capacity of the StringBuilder instance can grow beyond the value of its MaxCapacity property. 這可能特別是當您呼叫Append(String)AppendFormat(String, Object)附加小字串的方法。This can occur particularly when you call the Append(String) and AppendFormat(String, Object) methods to append small strings.

另請參閱

AppendFormat(IFormatProvider, String, Object, Object) AppendFormat(IFormatProvider, String, Object, Object) AppendFormat(IFormatProvider, String, Object, Object) AppendFormat(IFormatProvider, String, Object, Object)

將處理複合格式字串所傳回的字串 (其中包含零或更多的格式項目) 附加至這個執行個體。Appends the string returned by processing a composite format string, which contains zero or more format items, to this instance. 使用指定的格式提供者,將每個格式項目取代為兩個引數中的其中一個字串表示。Each format item is replaced by the string representation of either of two arguments using a specified format provider.

public:
 System::Text::StringBuilder ^ AppendFormat(IFormatProvider ^ provider, System::String ^ format, System::Object ^ arg0, System::Object ^ arg1);
public System.Text.StringBuilder AppendFormat (IFormatProvider provider, string format, object arg0, object arg1);
member this.AppendFormat : IFormatProvider * string * obj * obj -> System.Text.StringBuilder
Public Function AppendFormat (provider As IFormatProvider, format As String, arg0 As Object, arg1 As Object) As StringBuilder

參數

provider
IFormatProvider IFormatProvider IFormatProvider IFormatProvider

物件,提供特定文化特性格式資訊。An object that supplies culture-specific formatting information.

format
String String String String

複合格式字串。A composite format string.

arg0
Object Object Object Object

要格式化的第一個物件。The first object to format.

arg1
Object Object Object Object

要格式化的第二個物件。The second object to format.

傳回

完成附加作業之後,這個執行個體的參考。A reference to this instance after the append operation has completed. 在附加作業之後,此執行個體會包含此作業之前已存在的所有資料,並後置有 format 的複本,其中的任何格式規格都會由對應物件引數的字串表示所取代。After the append operation, this instance contains any data that existed before the operation, suffixed by a copy of format where any format specification is replaced by the string representation of the corresponding object argument.

例外狀況

format 無效。format is invalid.

-或--or- 格式項目的索引小於 0 (零) 或大於等於 2 (二)。The index of a format item is less than 0 (zero), or greater than or equal to 2 (two).

展開後的字串長度會超過 MaxCapacityThe length of the expanded string would exceed MaxCapacity.

範例

下列範例會使用AppendFormat(IFormatProvider, String, Object, Object)方法,以顯示儲存在一般時間和溫度資料Dictionary<TKey,TValue>物件。The following example uses the AppendFormat(IFormatProvider, String, Object, Object) method to display time and temperature data stored in a generic Dictionary<TKey,TValue> object. 請注意,格式字串三個格式項目,雖然有只能以要格式化的物件。Note that the format string has three format items, although there are only to objects to format. 這是因為在清單中 (日期和時間值) 的第一個物件由兩個格式項目:第一個格式項目會顯示第二個情況下,就會顯示日期。This is because the first object in the list (a date and time value) is used by two format items: The first format item displays the time, and the second displays the date.

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Text;

public class Example
{
   public static void Main()
   {
      CultureInfo culture = new CultureInfo("en-US");
      StringBuilder sb = new StringBuilder();
      Dictionary<DateTime, Double> temperatureInfo = new Dictionary<DateTime, Double>(); 
      temperatureInfo.Add(new DateTime(2010, 6, 1, 14, 0, 0), 87.46);
      temperatureInfo.Add(new DateTime(2010, 12, 1, 10, 0, 0), 36.81);
      

      sb.AppendLine("Temperature Information:\n");
      foreach (var item in temperatureInfo)
      {
         sb.AppendFormat(culture,
                         "Temperature at {0,8:t} on {0,9:d}: {1,5:N1}°F\n",
                         item.Key, item.Value);
      }
      Console.WriteLine(sb.ToString());
   }
}
// The example displays the following output:
//       Temperature Information:
//       
//       Temperature at  2:00 PM on  6/1/2010:  87.5°F
//       Temperature at 10:00 AM on 12/1/2010:  36.8°F
Imports System.Collections.Generic
Imports System.Globalization
Imports System.Text

Module Example
   Public Sub Main()
      Dim culture As New CultureInfo("en-US")
      Dim sb As New StringBuilder()
      Dim temperatureInfo As New Dictionary(Of Date, Double) 
      temperatureInfo.Add(#6/1/2010 2:00PM#, 87.46)
      temperatureInfo.Add(#12/1/2010 10:00AM#, 36.81)
      
      sb.AppendLine("Temperature Information:").AppendLine()
      For Each item In temperatureInfo
         sb.AppendFormat(culture,
                         "Temperature at {0,8:t} on {0,9:d}: {1,5:N1}°F",
                         item.Key, item.Value).AppendLine()
      Next
      Console.WriteLine(sb.ToString())
   End Sub
End Module
' The example displays the following output:
'       Temperature Information:
'       
'       Temperature at  2:00 PM on  6/1/2010:  87.5°F
'       Temperature at 10:00 AM on 12/1/2010:  36.8°F

備註

這個方法會使用複合格式功能物件的值轉換成其文字表示,並將該表示內嵌在目前的.NET frameworkStringBuilder物件。This method uses the composite formatting feature of the .NET Framework to convert the value of an object to its text representation and embed that representation in the current StringBuilder object.

format參數是由零個或多個文字執行混合零或多個索引的預留位置,稱為格式項目,對應至這個方法的參數清單中的物件。The format parameter consists of zero or more runs of text intermixed with zero or more indexed placeholders, called format items, that correspond to objects in the parameter list of this method. 格式化的程序會將每個格式項目取代對應的物件的字串表示。The formatting process replaces each format item with the string representation of the corresponding object.

格式項目的語法如下所示:The syntax of a format item is as follows:

{index[,length][:formatString]}{index[,length][:formatString]}

在方括號中的元素是選擇性的元素。Elements in square brackets are optional. 下表說明每個元素。The following table describes each element.

元素Element 說明Description
indexindex 參數清單中要格式化之物件的以零為起始位置。The zero-based position in the parameter list of the object to be formatted. 如果所指定的物件indexnull,格式項目取代為String.EmptyIf the object specified by index is null, the format item is replaced by String.Empty. 如果在沒有參數index位置,FormatException就會擲回。If there is no parameter in the index position, a FormatException is thrown.
,length,length 參數的字串表示法中的字元數目下限。The minimum number of characters in the string representation of the parameter. 如果是正數,參數會靠右對齊;如果是負數,它是靠左對齊。If positive, the parameter is right-aligned; if negative, it is left-aligned.
:formatString:formatString 標準或自訂格式字串所支援的參數。A standard or custom format string that is supported by the parameter.

注意

搭配日期和時間值的標準和自訂格式字串,請參閱 < 標準日期和時間格式字串自訂日期和時間格式字串For the standard and custom format strings used with date and time values, see Standard Date and Time Format Strings and Custom Date and Time Format Strings. 針對搭配數值使用標準和自訂格式字串,請參閱標準數值格式字串自訂數值格式字串For the standard and custom format strings used with numeric values, see Standard Numeric Format Strings and Custom Numeric Format Strings. 列舉型別搭配使用的標準格式字串,請參閱 < 列舉格式字串For the standard format strings used with enumerations, see Enumeration Format Strings.

provider參數指定IFormatProvider實作,可提供格式設定資訊arg0arg1The provider parameter specifies an IFormatProvider implementation that can provide formatting information for arg0 and arg1. provider 可以是下列任何項目:provider can be any of the following:

  • ACultureInfo提供特定文化特性格式資訊的物件。A CultureInfo object that provides culture-specific formatting information.

  • ANumberFormatInfo提供特定文化特性格式資訊的物件arg0arg1如果它們是數值。A NumberFormatInfo object that provides culture-specific formatting information for arg0 or arg1 if they are numeric values.

  • ADateTimeFormatInfo提供特定文化特性格式資訊的物件arg0arg1有日期和時間值。A DateTimeFormatInfo object that provides culture-specific formatting information for arg0 or arg1 if they are date and time values.

  • 自訂IFormatProvider實作,提供格式設定資訊arg0arg1A custom IFormatProvider implementation that provides formatting information for arg0 and arg1. 一般而言,這類實作也會實作ICustomFormatter介面。Typically, such an implementation also implements the ICustomFormatter interface.

如果provider參數是null,格式提供者資訊取自目前文化特性。If the provider parameter is null, format provider information is obtained from the current culture.

arg0arg1表示要格式化的物件。arg0 and arg1 represent the objects to be formatted. 中的每個格式項目format會取代具有對應的索引之物件的字串表示。Each format item in format is replaced with the string representation of the object that has the corresponding index. 如果格式項目包含formatString並實作相對應的引數IFormattable介面,則該引數的ToString(formatString, provider)方法可讓您定義的格式。If the format item includes formatString and the corresponding argument implements the IFormattable interface, then the argument's ToString(formatString, provider) method defines the formatting. 否則,引數的ToString()方法可讓您定義的格式。Otherwise, the argument's ToString() method defines the formatting.

給呼叫者的注意事項

在.NET Core 和.NET Framework 4.0 和更新版本中,當您具現化StringBuilder藉由呼叫物件StringBuilder(Int32, Int32)建構函式,長度和容量StringBuilder執行個體可以成長的值超過其MaxCapacity屬性。IIn .NET Core and in the .NET Framework 4.0 and later versions, when you instantiate the StringBuilder object by calling the StringBuilder(Int32, Int32) constructor, both the length and the capacity of the StringBuilder instance can grow beyond the value of its MaxCapacity property. 這可能特別是當您呼叫Append(String)AppendFormat(String, Object)附加小字串的方法。This can occur particularly when you call the Append(String) and AppendFormat(String, Object) methods to append small strings.

另請參閱

AppendFormat(String, Object, Object, Object) AppendFormat(String, Object, Object, Object) AppendFormat(String, Object, Object, Object) AppendFormat(String, Object, Object, Object)

將處理複合格式字串所傳回的字串 (其中包含零或更多的格式項目) 附加至這個執行個體。Appends the string returned by processing a composite format string, which contains zero or more format items, to this instance. 每一個格式項目都會取代為三個引數中任一個的字串表示。Each format item is replaced by the string representation of either of three arguments.

public:
 System::Text::StringBuilder ^ AppendFormat(System::String ^ format, System::Object ^ arg0, System::Object ^ arg1, System::Object ^ arg2);
public System.Text.StringBuilder AppendFormat (string format, object arg0, object arg1, object arg2);
member this.AppendFormat : string * obj * obj * obj -> System.Text.StringBuilder
Public Function AppendFormat (format As String, arg0 As Object, arg1 As Object, arg2 As Object) As StringBuilder

參數

format
String String String String

複合格式字串。A composite format string.

arg0
Object Object Object Object

要格式化的第一個物件。The first object to format.

arg1
Object Object Object Object

要格式化的第二個物件。The second object to format.

arg2
Object Object Object Object

要格式化的第三個物件。The third object to format.

傳回

附加 format 的執行個體參考。A reference to this instance with format appended. format 中的每一個格式項目會由對應之物件引數的字串表示所取代。Each format item in format is replaced by the string representation of the corresponding object argument.

例外狀況

format 無效。format is invalid.

-或--or- 格式項目的索引小於 0 (零) 或大於等於 3。The index of a format item is less than 0 (zero), or greater than or equal to 3.

展開後的字串長度會超過 MaxCapacityThe length of the expanded string would exceed MaxCapacity.

範例

下列範例示範AppendFormat方法。The following example demonstrates the AppendFormat method.

using namespace System;
using namespace System::Text;
using namespace System::Globalization;
void Show( StringBuilder^ sbs )
{
   Console::WriteLine( sbs );
   sbs->Length = 0;
}

int main()
{
   StringBuilder^ sb = gcnew StringBuilder;
   int var1 = 111;
   float var2 = 2.22F;
   String^ var3 = "abcd";
   array<Object^>^var4 = {3,4.4,(Char)'X'};
   Console::WriteLine();
   Console::WriteLine( "StringBuilder.AppendFormat method:" );
   sb->AppendFormat( "1) {0}", var1 );
   Show( sb );
   sb->AppendFormat( "2) {0}, {1}", var1, var2 );
   Show( sb );
   sb->AppendFormat( "3) {0}, {1}, {2}", var1, var2, var3 );
   Show( sb );
   sb->AppendFormat( "4) {0}, {1}, {2}", var4 );
   Show( sb );
   CultureInfo^ ci = gcnew CultureInfo( "es-ES",true );
   array<Object^>^temp1 = {var2};
   sb->AppendFormat( ci, "5) {0}", temp1 );
   Show( sb );
}

/*
This example produces the following results:

StringBuilder.AppendFormat method:
1) 111
2) 111, 2.22
3) 111, 2.22, abcd
4) 3, 4.4, X
5) 2,22
*/
using System;
using System.Text;
using System.Globalization;

class Sample 
{
    static StringBuilder sb = new StringBuilder();

    public static void Main() 
    {
    int    var1   = 111;
    float  var2   = 2.22F;
    string var3   = "abcd";
    object[] var4 = {3, 4.4, 'X'};

    Console.WriteLine();
    Console.WriteLine("StringBuilder.AppendFormat method:");
    sb.AppendFormat("1) {0}", var1);
    Show(sb);
    sb.AppendFormat("2) {0}, {1}", var1, var2);
    Show(sb);
    sb.AppendFormat("3) {0}, {1}, {2}", var1, var2, var3);
    Show(sb);
    sb.AppendFormat("4) {0}, {1}, {2}", var4);
    Show(sb);
    CultureInfo ci = new CultureInfo("es-ES", true);
    sb.AppendFormat(ci, "5) {0}", var2);
    Show(sb);
    }

    public static void Show(StringBuilder sbs)
    {
    Console.WriteLine(sbs.ToString());
    sb.Length = 0;
    }
}
/*
This example produces the following results:

StringBuilder.AppendFormat method:
1) 111
2) 111, 2.22
3) 111, 2.22, abcd
4) 3, 4.4, X
5) 2,22
*/
Imports System
Imports System.Text
Imports System.Globalization

Class Sample
   Private Shared sb As New StringBuilder()

   Public Shared Sub Main()
      Dim var1 As Integer = 111
      Dim var2 As Single = 2.22F
      Dim var3 As String = "abcd"
      Dim var4 As Object() =  {3, 4.4, "X"c}
      
      Console.WriteLine()
      Console.WriteLine("StringBuilder.AppendFormat method:")
      sb.AppendFormat("1) {0}", var1)
      Show(sb)
      sb.AppendFormat("2) {0}, {1}", var1, var2)
      Show(sb)
      sb.AppendFormat("3) {0}, {1}, {2}", var1, var2, var3)
      Show(sb)
      sb.AppendFormat("4) {0}, {1}, {2}", var4)
      Show(sb)
      Dim ci As New CultureInfo("es-ES", True)
      sb.AppendFormat(ci, "5) {0}", var2)
      Show(sb)
   End Sub 'Main
   
   Public Shared Sub Show(sbs As StringBuilder)
      Console.WriteLine(sbs.ToString())
      sb.Length = 0
   End Sub 'Show
End Class 'Sample
'
'This example produces the following results:
'
'StringBuilder.AppendFormat method:
'1) 111
'2) 111, 2.22
'3) 111, 2.22, abcd
'4) 3, 4.4, X
'5) 2,22

備註

這個方法會使用複合格式功能物件的值轉換成其文字表示,並將該表示內嵌在目前的.NET frameworkStringBuilder物件。This method uses the composite formatting feature of the .NET Framework to convert the value of an object to its text representation and embed that representation in the current StringBuilder object.

format參數是由零個或多個文字執行混合零或多個索引的預留位置,稱為格式項目,對應至arg0透過arg2,這個方法的參數清單中的物件。The format parameter consists of zero or more runs of text intermixed with zero or more indexed placeholders, called format items, that correspond to arg0 through arg2, the objects in the parameter list of this method. 格式化的程序會將每個格式項目取代對應的物件的字串表示。The formatting process replaces each format item with the string representation of the corresponding object.

格式項目的語法如下所示:The syntax of a format item is as follows:

{index[,length][:formatString]}{index[,length][:formatString]}

在方括號中的元素是選擇性的元素。Elements in square brackets are optional. 下表說明每個元素。The following table describes each element.

元素Element 描述Description
indexindex 參數清單中要格式化之物件的以零為起始位置。The zero-based position in the parameter list of the object to be formatted. 如果所指定的物件indexnull,格式項目取代為String.EmptyIf the object specified by index is null, the format item is replaced by String.Empty. 如果在沒有參數index位置,FormatException就會擲回。If there is no parameter in the index position, a FormatException is thrown.
,length,length 參數的字串表示法中的字元數目下限。The minimum number of characters in the string representation of the parameter. 如果是正數,參數會靠右對齊;如果是負數,它是靠左對齊。If positive, the parameter is right-aligned; if negative, it is left-aligned.
:formatString:formatString 標準或自訂格式字串所支援的參數。A standard or custom format string that is supported by the parameter.

注意

搭配日期和時間值的標準和自訂格式字串,請參閱 < 標準日期和時間格式字串自訂日期和時間格式字串For the standard and custom format strings used with date and time values, see Standard Date and Time Format Strings and Custom Date and Time Format Strings. 針對搭配數值使用標準和自訂格式字串,請參閱標準數值格式字串自訂數值格式字串For the standard and custom format strings used with numeric values, see Standard Numeric Format Strings and Custom Numeric Format Strings. 列舉型別搭配使用的標準格式字串,請參閱 < 列舉格式字串For the standard format strings used with enumerations, see Enumeration Format Strings.

arg0``arg1,和arg2表示要格式化的物件。arg0, arg1, and arg2 represent the objects to be formatted. 中的每個格式項目format任一個的字串表示取代arg0arg1,或arg2,視使用的格式項目的索引。Each format item in format is replaced with the string representation of either arg0, arg1, or arg2, depending on the index of the format item. 如果格式項目包含formatString中對應的物件args實作IFormattable介面,然後arg x .ToString(formatString, null)其中定義的格式、 x是引數的索引。If the format item includes formatString and the corresponding object in args implements the IFormattable interface, then argx.ToString(formatString, null) defines the formatting, where x is the index of the argument. 否則,請arg x .ToString()定義的格式。Otherwise, argx.ToString() defines the formatting.

如果字串指派給format是 「 感謝您捐贈 {0: # # #} 罐食物給本慈善組織。 」If the string assigned to format is "Thank you for your donation of {0:####} cans of food to our charitable organization." arg0是一個整數值為 10,傳回的值會是 「 謝謝您捐贈 10 罐食物給本慈善組織。 」and arg0 is an integer with the value 10, the return value will be "Thank you for your donation of 10 cans of food to our charitable organization."

給呼叫者的注意事項

在.NET Core 和.NET Framework 4.0 和更新版本中,當您具現化StringBuilder藉由呼叫物件StringBuilder(Int32, Int32)建構函式,長度和容量StringBuilder執行個體可以成長的值超過其MaxCapacity屬性。In .NET Core and in the .NET Framework 4.0 and later versions, when you instantiate the StringBuilder object by calling the StringBuilder(Int32, Int32) constructor, both the length and the capacity of the StringBuilder instance can grow beyond the value of its MaxCapacity property. 這可能特別是當您呼叫Append(String)AppendFormat(String, Object)附加小字串的方法。This can occur particularly when you call the Append(String) and AppendFormat(String, Object) methods to append small strings.

另請參閱

適用於