Byte.TryParse 方法

定义

尝试将数字的字符串表示形式转换为它的等效 Byte,并返回一个指示转换是否成功的值。Tries to convert the string representation of a number to its Byte equivalent, and returns a value that indicates whether the conversion succeeded.

重载

TryParse(String, Byte)

尝试将数字的字符串表示形式转换为它的等效 Byte,并返回一个指示转换是否成功的值。Tries to convert the string representation of a number to its Byte equivalent, and returns a value that indicates whether the conversion succeeded.

TryParse(ReadOnlySpan<Char>, Byte)

尝试将数字的范围表示形式转换为它的等效 Byte,并返回一个指示转换是否成功的值。Tries to convert the span representation of a number to its Byte equivalent, and returns a value that indicates whether the conversion succeeded.

TryParse(String, NumberStyles, IFormatProvider, Byte)

将指定样式和区域性特定格式的数字的字符串表示形式转换为它的等效 ByteConverts the string representation of a number in a specified style and culture-specific format to its Byte equivalent. 一个指示转换是否成功的返回值。A return value indicates whether the conversion succeeded or failed.

TryParse(ReadOnlySpan<Char>, NumberStyles, IFormatProvider, Byte)

将指定样式和区域性特定格式的数字的范围表示形式转换为它的等效 ByteConverts the span representation of a number in a specified style and culture-specific format to its Byte equivalent. 一个指示转换是否成功的返回值。A return value indicates whether the conversion succeeded or failed.

TryParse(String, Byte)

尝试将数字的字符串表示形式转换为它的等效 Byte,并返回一个指示转换是否成功的值。Tries to convert the string representation of a number to its Byte equivalent, and returns a value that indicates whether the conversion succeeded.

public:
 static bool TryParse(System::String ^ s, [Runtime::InteropServices::Out] System::Byte % result);
public static bool TryParse (string s, out byte result);
static member TryParse : string * byte -> bool
Public Shared Function TryParse (s As String, ByRef result As Byte) As Boolean

参数

s
String

包含要转换的数字的字符串。A string that contains a number to convert.

result
Byte

当此方法返回时,如果转换成功,则包含与 Byte 中所包含的数字等效的 s 值;如果转换失败,则包含零。When this method returns, contains the Byte value equivalent to the number contained in s if the conversion succeeded, or zero if the conversion failed. 此参数未经初始化即进行传递;最初在 result 中提供的任何值都会被覆盖。This parameter is passed uninitialized; any value originally supplied in result will be overwritten.

返回

如果 true 成功转换,则为 s;否则为 falsetrue if s was converted successfully; otherwise, false.

示例

下面的示例使用多个不同的字符串值调用 TryParse(String, Byte) 方法。The following example calls the TryParse(String, Byte) method with a number of different string values.

using namespace System;

void main()
{
   array<String^>^ byteStrings = gcnew array<String^> { nullptr, String::Empty, 
                                                        "1024", "100.1", "100", 
                                                        "+100", "-100", "000000000000000100", 
                                                        "00,100", "   20   ", "FF", "0x1F" };
   Byte byteValue;
   for each (String^ byteString in byteStrings) {
      bool result = Byte::TryParse(byteString, byteValue);
      if (result)
         Console::WriteLine("Converted '{0}' to {1}", 
                            byteString, byteValue);
      else
         Console::WriteLine("Attempted conversion of '{0}' failed.", 
                            byteString);
   }
}
// The example displays the following output:
//       Attempted conversion of '' failed.
//       Attempted conversion of '' failed.`
//       Attempted conversion of '1024' failed.
//       Attempted conversion of '100.1' failed.
//       Converted '100' to 100
//       Converted '+100' to 100
//       Attempted conversion of '-100' failed.
//       Converted '000000000000000100' to 100
//       Attempted conversion of '00,100' failed.
//       Converted '   20   ' to 20
//       Attempted conversion of 'FF' failed.
//       Attempted conversion of '0x1F' failed.}
using System;

public class ByteConversion
{
   public static void Main()
   {
      string[] byteStrings = { null, string.Empty, "1024",
                               "100.1", "100", "+100", "-100",
                               "000000000000000100", "00,100",
                               "   20   ", "FF", "0x1F" };

      foreach (var byteString in byteStrings)
      {
          CallTryParse(byteString);
      }
   }

   private static void CallTryParse(string stringToConvert)
   {  
      byte byteValue; 
      bool success = Byte.TryParse(stringToConvert, out byteValue);
      if (success)
      {
         Console.WriteLine("Converted '{0}' to {1}", 
                        stringToConvert, byteValue);
      }
      else
      {
         Console.WriteLine("Attempted conversion of '{0}' failed.", 
                           stringToConvert);
      }
   }    
}
// The example displays the following output to the console:
//       Attempted conversion of '' failed.
//       Attempted conversion of '' failed.
//       Attempted conversion of '1024' failed.
//       Attempted conversion of '100.1' failed.
//       Converted '100' to 100
//       Converted '+100' to 100
//       Attempted conversion of '-100' failed.
//       Converted '000000000000000100' to 100
//       Attempted conversion of '00,100' failed.
//       Converted '   20   ' to 20
//       Attempted conversion of 'FF' failed.
//       Attempted conversion of '0x1F' failed.
Module ByteConversion
   Public Sub Main()
      Dim byteStrings() As String = { Nothing, String.Empty, "1024", 
                                    "100.1", "100", "+100", "-100",
                                    "000000000000000100", "00,100",
                                    "   20   ", "FF", "0x1F"}

      For Each byteString As String In byteStrings
        CallTryParse(byteString)
      Next
   End Sub
   
   Private Sub CallTryParse(stringToConvert As String)  
      Dim byteValue As Byte
      Dim success As Boolean = Byte.TryParse(stringToConvert, byteValue)
      If success Then
         Console.WriteLine("Converted '{0}' to {1}", _
                        stringToConvert, byteValue)
      Else
         Console.WriteLine("Attempted conversion of '{0}' failed.", _
                           stringToConvert)
      End If                        
   End Sub
End Module
' The example displays the following output to the console:
'       Attempted conversion of '' failed.
'       Attempted conversion of '' failed.
'       Attempted conversion of '1024' failed.
'       Attempted conversion of '100.1' failed.
'       Converted '100' to 100
'       Converted '+100' to 100
'       Attempted conversion of '-100' failed.
'       Converted '000000000000000100' to 100
'       Attempted conversion of '00,100' failed.
'       Converted '   20   ' to 20
'       Attempted conversion of 'FF' failed.
'       Attempted conversion of '0x1F' failed.

注解

如果 s 参数的格式不正确(如果是 nullString.Empty),或者表示的数字小于 MinValue 或大于 MaxValue,则转换将失败,并且方法将返回 falseThe conversion fails and the method returns false if the s parameter is not in the correct format, if it is null or String.Empty, or if it represents a number less than MinValue or greater than MaxValue.

Byte.TryParse(String, Byte) 方法与 Byte.Parse(String) 方法类似,不同之处在于 TryParse(String, Byte) 不会在转换失败时引发异常。The Byte.TryParse(String, Byte) method is similar to the Byte.Parse(String) method, except that TryParse(String, Byte) does not throw an exception if the conversion fails.

s 参数应为以下形式的数字的字符串表示形式:The s parameter should be the string representation of a number in the following form:

[ws][sign]digits[ws]  

方括号 ([ and ]) 中的元素是可选的。Elements in square brackets ([ and ]) are optional. 下表对每个元素进行了描述。The following table describes each element.

元素Element 说明Description
wsws 可选空白。Optional white space.
signsign 可选正号,由当前区域性的 NumberFormatInfo.PositiveSign 属性指定。An optional positive sign, as specified by the NumberFormatInfo.PositiveSign property of the current culture.
digitsdigits 十进制数字的序列,范围为0到9。A sequence of decimal digits that range from 0 to 9.

使用 Integer 样式对 s 参数进行解释。The s parameter is interpreted using the Integer style. 除了字节值的十进制数外,只允许使用前导和尾随空格以及前导符号。In addition to the byte value's decimal digits, only leading and trailing spaces together with a leading sign are allowed. (如果存在符号,则它必须是正号,否则方法会引发 OverflowException。)若要将样式元素与 s中可以存在的区域性特定格式设置信息一起显式定义,请使用 Byte.Parse(String, NumberStyles, IFormatProvider) 方法。(If the sign is present, it must be a positive sign or the method throws an OverflowException.) To explicitly define the style elements together with the culture-specific formatting information that can be present in s, use the Byte.Parse(String, NumberStyles, IFormatProvider) method.

使用当前区域性的 NumberFormatInfo 对象中的格式设置信息对 s 参数进行分析。The s parameter is parsed using the formatting information in a NumberFormatInfo object for the current culture. 有关详细信息,请参阅 NumberFormatInfo.CurrentInfoFor more information, see NumberFormatInfo.CurrentInfo.

Byte.TryParse(String, Byte) 方法的此重载将 s 参数中的所有数字解释为十进制数字。This overload of the Byte.TryParse(String, Byte) method interprets all digits in the s parameter as decimal digits. 若要分析十六进制数的字符串表示形式,请调用 Byte.TryParse(String, NumberStyles, IFormatProvider, Byte) 重载。To parse the string representation of a hexadecimal number, call the Byte.TryParse(String, NumberStyles, IFormatProvider, Byte) overload.

另请参阅

TryParse(ReadOnlySpan<Char>, Byte)

尝试将数字的范围表示形式转换为它的等效 Byte,并返回一个指示转换是否成功的值。Tries to convert the span representation of a number to its Byte equivalent, and returns a value that indicates whether the conversion succeeded.

public:
 static bool TryParse(ReadOnlySpan<char> s, [Runtime::InteropServices::Out] System::Byte % result);
public static bool TryParse (ReadOnlySpan<char> s, out byte result);
static member TryParse : ReadOnlySpan<char> * byte -> bool
Public Shared Function TryParse (s As ReadOnlySpan(Of Char), ByRef result As Byte) As Boolean

参数

s
ReadOnlySpan<Char>

一个范围,包含表示要转换的数字的字符。A span containing the characters representing the number to convert.

result
Byte

当此方法返回时,如果转换成功,则包含与 Byte 中所包含的数字等效的 s 值;如果转换失败,则包含零。When this method returns, contains the Byte value equivalent to the number contained in s if the conversion succeeded, or zero if the conversion failed. 此参数未经初始化即进行传递;最初在 result 中提供的任何值都会被覆盖。This parameter is passed uninitialized; any value originally supplied in result will be overwritten.

返回

如果 true 成功转换,则为 s;否则为 falsetrue if s was converted successfully; otherwise, false.

TryParse(String, NumberStyles, IFormatProvider, Byte)

将指定样式和区域性特定格式的数字的字符串表示形式转换为它的等效 ByteConverts the string representation of a number in a specified style and culture-specific format to its Byte equivalent. 一个指示转换是否成功的返回值。A return value indicates whether the conversion succeeded or failed.

public:
 static bool TryParse(System::String ^ s, System::Globalization::NumberStyles style, IFormatProvider ^ provider, [Runtime::InteropServices::Out] System::Byte % result);
public static bool TryParse (string s, System.Globalization.NumberStyles style, IFormatProvider provider, out byte result);
static member TryParse : string * System.Globalization.NumberStyles * IFormatProvider * byte -> bool
Public Shared Function TryParse (s As String, style As NumberStyles, provider As IFormatProvider, ByRef result As Byte) As Boolean

参数

s
String

包含要转换的数字的字符串。A string containing a number to convert. 该字符串使用由 style 指定的样式来进行解释。The string is interpreted using the style specified by style.

style
NumberStyles

枚举值的按位组合,用于指示可出现在 s 中的样式元素。A bitwise combination of enumeration values that indicates the style elements that can be present in s. 要指定的一个典型值为 IntegerA typical value to specify is Integer.

provider
IFormatProvider

一个对象,提供有关 s 的区域性特定格式设置信息。An object that supplies culture-specific formatting information about s. 如果 providernull,则使用当前区域性。If provider is null, the thread current culture is used.

result
Byte

当此方法返回时,如果转换成功,则包含与 s 中所含数字等效的 8 位无符号整数值;如果转换失败,则包含零。When this method returns, contains the 8-bit unsigned integer value equivalent to the number contained in s if the conversion succeeded, or zero if the conversion failed. 如果 s 参数为 nullEmpty、格式不正确,或者表示的数字小于 MinValue 或大于 MaxValue,则转换失败。The conversion fails if the s parameter is null or Empty, is not of the correct format, or represents a number less than MinValue or greater than MaxValue. 此参数未经初始化即进行传递;最初在 result 中提供的任何值都会被覆盖。This parameter is passed uninitialized; any value originally supplied in result will be overwritten.

返回

如果 true 成功转换,则为 s;否则为 falsetrue if s was converted successfully; otherwise, false.

异常

style 不是 NumberStyles 值。style is not a NumberStyles value.

- 或 --or- style 不是 AllowHexSpecifierHexNumber 值的组合。style is not a combination of AllowHexSpecifier and HexNumber values.

示例

下面的示例使用多个不同的字符串值调用 TryParse(String, NumberStyles, IFormatProvider, Byte) 方法。The following example calls the TryParse(String, NumberStyles, IFormatProvider, Byte) method with a number of different string values.

using namespace System;
using namespace System::Globalization;

void CallTryParse(String^ byteString, NumberStyles styles);

void main()
{
   String^ byteString; 
   NumberStyles styles;

   byteString = "1024";
   styles = NumberStyles::Integer;
   CallTryParse(byteString, styles);

   byteString = "100.1";
   styles = NumberStyles::Integer | NumberStyles::AllowDecimalPoint;
   CallTryParse(byteString, styles);

   byteString = "100.0";
   CallTryParse(byteString, styles);

   byteString = "+100";
   styles = NumberStyles::Integer | NumberStyles::AllowLeadingSign 
            | NumberStyles::AllowTrailingSign;
   CallTryParse(byteString, styles);

   byteString = "-100";
   CallTryParse(byteString, styles);

   byteString = "000000000000000100";
   CallTryParse(byteString, styles);

   byteString = "00,100";
   styles = NumberStyles::Integer | NumberStyles::AllowThousands;
   CallTryParse(byteString, styles);

   byteString = "2E+3   ";
   styles = NumberStyles::Integer | NumberStyles::AllowExponent;
   CallTryParse(byteString, styles);

   byteString = "FF";
   styles = NumberStyles::HexNumber;
   CallTryParse(byteString, styles);

   byteString = "0x1F";
   CallTryParse(byteString, styles);
}

void CallTryParse(String^ stringToConvert, NumberStyles styles)
{  
   Byte byteValue;
   bool result = Byte::TryParse(stringToConvert, styles, 
                                 (IFormatProvider^) nullptr , byteValue);
   if (result)
      Console::WriteLine("Converted '{0}' to {1}", 
                     stringToConvert, byteValue);
   else
      Console::WriteLine("Attempted conversion of '{0}' failed.", 
                        stringToConvert);
}
// The example displays the following output:
//       Attempted conversion of '1024' failed.
//       Attempted conversion of '100.1' failed.
//       Converted '100.0' to 100
//       Converted '+100' to 100
//       Attempted conversion of '-100' failed.
//       Converted '000000000000000100' to 100
//       Converted '00,100' to 100
//       Attempted conversion of '2E+3   ' failed.
//       Converted 'FF' to 255
//       Attempted conversion of '0x1F' failed.}
using System;
using System.Globalization;

public class ByteConversion2
{
   public static void Main()
   {
      string byteString; 
      NumberStyles styles;
      
      byteString = "1024";
      styles = NumberStyles.Integer;
      CallTryParse(byteString, styles);
      
      byteString = "100.1";
      styles = NumberStyles.Integer | NumberStyles.AllowDecimalPoint;
      CallTryParse(byteString, styles);
      
      byteString = "100.0";
      CallTryParse(byteString, styles);
      
      byteString = "+100";
      styles = NumberStyles.Integer | NumberStyles.AllowLeadingSign 
               | NumberStyles.AllowTrailingSign;
      CallTryParse(byteString, styles);
      
      byteString = "-100";
      CallTryParse(byteString, styles);
      
      byteString = "000000000000000100";
      CallTryParse(byteString, styles);
      
      byteString = "00,100";
      styles = NumberStyles.Integer | NumberStyles.AllowThousands;
      CallTryParse(byteString, styles);
      
      byteString = "2E+3   ";
      styles = NumberStyles.Integer | NumberStyles.AllowExponent;
      CallTryParse(byteString, styles);
      
      byteString = "FF";
      styles = NumberStyles.HexNumber;
      CallTryParse(byteString, styles);
      
      byteString = "0x1F";
      CallTryParse(byteString, styles);
   }

   private static void CallTryParse(string stringToConvert, NumberStyles styles)
   {  
      Byte byteValue;
      bool result = Byte.TryParse(stringToConvert, styles, 
                                  null as IFormatProvider, out byteValue);
      if (result)
         Console.WriteLine("Converted '{0}' to {1}", 
                        stringToConvert, byteValue);
      else
         Console.WriteLine("Attempted conversion of '{0}' failed.", 
                           stringToConvert.ToString());
   }
}
// The example displays the following output to the console:
//       Attempted conversion of '1024' failed.
//       Attempted conversion of '100.1' failed.
//       Converted '100.0' to 100
//       Converted '+100' to 100
//       Attempted conversion of '-100' failed.
//       Converted '000000000000000100' to 100
//       Converted '00,100' to 100
//       Attempted conversion of '2E+3   ' failed.
//       Converted 'FF' to 255
//       Attempted conversion of '0x1F' failed.
Imports System.Globalization

Module ByteConversion2
   Public Sub Main()
      Dim byteString As String 
      Dim styles As NumberStyles
      
      byteString = "1024"
      styles = NumberStyles.Integer
      CallTryParse(byteString, styles)
      
      byteString = "100.1"
      styles = NumberStyles.Integer Or NumberStyles.AllowDecimalPoint
      CallTryParse(byteString, styles)
      
      byteString = "100.0"
      CallTryParse(byteString, styles)
      
      byteString = "+100"
      styles = NumberStyles.Integer Or NumberStyles.AllowLeadingSign _
               Or NumberStyles.AllowTrailingSign
      CallTryParse(byteString, styles)
      
      byteString = "-100"
      CallTryParse(byteString, styles)
      
      byteString = "000000000000000100"
      CallTryParse(byteString, styles)
      
      byteString = "00,100"      
      styles = NumberStyles.Integer Or NumberStyles.AllowThousands
      CallTryParse(byteString, styles)
      
      byteString = "2E+3   "
      styles = NumberStyles.Integer Or NumberStyles.AllowExponent
      CallTryParse(byteString, styles)
      
      byteString = "FF"
      styles = NumberStyles.HexNumber
      CallTryParse(byteString, styles)
      
      byteString = "0x1F"
      CallTryParse(byteString, styles)
   End Sub
   
   Private Sub CallTryParse(stringToConvert As String, styles As NumberStyles)  
      Dim byteValue As Byte
      Dim result As Boolean = Byte.TryParse(stringToConvert, styles, Nothing, _
                                            byteValue)
      If result Then
         Console.WriteLine("Converted '{0}' to {1}", _
                        stringToConvert, byteValue)
      Else
         If stringToConvert Is Nothing Then stringToConvert = ""
         Console.WriteLine("Attempted conversion of '{0}' failed.", _
                           stringToConvert.ToString())
      End If                        
   End Sub
End Module
' The example displays the following output to the console:
'       Attempted conversion of '1024' failed.
'       Attempted conversion of '100.1' failed.
'       Converted '100.0' to 100
'       Converted '+100' to 100
'       Attempted conversion of '-100' failed.
'       Converted '000000000000000100' to 100
'       Converted '00,100' to 100
'       Attempted conversion of '2E+3   ' failed.
'       Converted 'FF' to 255
'       Attempted conversion of '0x1F' failed.

注解

TryParse 方法类似于 Parse 方法,但如果转换失败,则 TryParse 方法不会引发异常。The TryParse method is like the Parse method, except the TryParse method does not throw an exception if the conversion fails.

s 参数使用 provider 参数提供的 NumberFormatInfo 对象中的格式设置信息进行分析。The s parameter is parsed using the formatting information in a NumberFormatInfo object supplied by the provider parameter.

Style 参数定义 s 参数中允许的样式元素(如空格或正号),以便分析操作成功。The style parameter defines the style elements (such as white space or the positive sign) that are allowed in the s parameter for the parse operation to succeed. 它必须是 NumberStyles 枚举中的位标志的组合。It must be a combination of bit flags from the NumberStyles enumeration. 根据 style的值,s 参数可能包括以下元素:Depending on the value of style, the s parameter may include the following elements:

[ws][$][sign]digits[.fractional_digits][e[sign]digits][ws][ws][$][sign]digits[.fractional_digits][e[sign]digits][ws]

如果 style 参数包括 AllowHexSpecifier,则为; 否则为:Or, if the style parameter includes AllowHexSpecifier:

[ws]hexdigits[ws][ws]hexdigits[ws]

方括号([和])中的元素是可选的。Elements in square brackets ( [ and ] ) are optional. 下表对每个元素进行了描述。The following table describes each element.

元素Element 说明Description
wsws 可选空白。Optional white space. 如果 style 包含 NumberStyles.AllowLeadingWhite 标志,或者如果样式包含 NumberStyles.AllowTrailingWhite 标志,则空格可以出现在 s 的开头。White space can appear at the beginning of s if style includes the NumberStyles.AllowLeadingWhite flag, or at the end of s if style includes the NumberStyles.AllowTrailingWhite flag.
$ 区域性特定的货币符号。A culture-specific currency symbol. 其在字符串中的位置由 provider 参数的 GetFormat 方法返回的 NumberFormatInfo 对象的 NumberFormatInfo.CurrencyPositivePattern 属性定义。Its position in the string is defined by the NumberFormatInfo.CurrencyPositivePattern property of the NumberFormatInfo object returned by the GetFormat method of the provider parameter. 如果 style 包含 NumberStyles.AllowCurrencySymbol 标志,货币符号可以出现在 s 中。The currency symbol can appear in s if style includes the NumberStyles.AllowCurrencySymbol flag.
signsign 可选正号。An optional positive sign. (如果 s中存在负号,则分析操作将失败。)如果 style 包含 NumberStyles.AllowLeadingSign 标志,s 或者如果 style 包含 NumberStyles.AllowTrailingSign 标志,则符号会出现在 s 的开头。(The parse operation fails if a negative sign is present in s.) The sign can appear at the beginning of s if style includes the NumberStyles.AllowLeadingSign flag, or at the end of s if style includes the NumberStyles.AllowTrailingSign flag.
digitsdigits 介于0到9之间的一系列数字。A sequence of digits from 0 through 9.
.. 区域性特定的小数点符号。A culture-specific decimal point symbol. 如果 style 包括 NumberStyles.AllowDecimalPoint 标志,则 provider 指定的区域性的小数点符号可以出现在 s 中。The decimal point symbol of the culture specified by provider can appear in s if style includes the NumberStyles.AllowDecimalPoint flag.
fractional_digitsfractional_digits 数字0的一个或多个匹配项。One or more occurrences of the digit 0. 仅当 style 包含 NumberStyles.AllowDecimalPoint 标志时,小数位才能出现在 s 中。Fractional digits can appear in s only if style includes the NumberStyles.AllowDecimalPoint flag.
ee E 或 E 字符,指示值以指数表示法表示。The e or E character, which indicates that the value is represented in exponential notation. 如果 style 包含 NumberStyles.AllowExponent 标志,则 s 参数可以表示指数表示法中的数字。The s parameter can represent a number in exponential notation if style includes the NumberStyles.AllowExponent flag.
hexdigitshexdigits 从0到 f 的十六进制数字序列,或者从0到 F。A sequence of hexadecimal digits from 0 through f, or 0 through F.

备注

无论 style 参数的值是什么,分析操作都将忽略 s 中任何终止的 NUL (U + 0000)字符。Any terminating NUL (U+0000) characters in s are ignored by the parsing operation, regardless of the value of the style argument.

仅包含十进制数字的字符串(对应于 NumberStyles.None 样式)始终会成功分析。A string with decimal digits only (which corresponds to the NumberStyles.None style) always parses successfully. 大多数其余 NumberStyles 成员控制可能但不要求出现在此输入字符串中的元素。Most of the remaining NumberStyles members control elements that may be but are not required to be present in this input string. 下表指示单个 NumberStyles 成员如何影响可能出现在 s中的元素。The following table indicates how individual NumberStyles members affect the elements that may be present in s.

非复合 NumberStyles 值Non-composite NumberStyles values 除数字外允许在 s 中使用的元素Elements permitted in s in addition to digits
NumberStyles.None 仅十进制数字。Decimal digits only.
NumberStyles.AllowDecimalPoint .The . fractional_digits元素。and fractional_digits elements. fractional_digits只能包含一个或多个0位数,否则该方法将返回 falseHowever, fractional_digits must consist of only one or more 0 digits or the method returns false.
NumberStyles.AllowExponent s 参数还可以使用指数表示法。The s parameter can also use exponential notation. 如果 s 表示指数表示法中的数字,则它必须表示 Byte 数据类型范围内的一个整数,而不包含非零的小数部分。If s represents a number in exponential notation, it must represent an integer within the range of the Byte data type without a non-zero, fractional component.
NumberStyles.AllowLeadingWhite s开头的ws元素。The ws element at the beginning of s.
NumberStyles.AllowTrailingWhite s末尾的ws元素。The ws element at the end of s.
NumberStyles.AllowLeadingSign 正负号可以出现在数字之前。A positive sign can appear before digits.
NumberStyles.AllowTrailingSign 正负号可以出现在数字之后。A positive sign can appear after digits.
NumberStyles.AllowParentheses 尽管支持此标志,但当 s中存在括号时,此方法将返回 falseAlthough this flag is supported, the method returns false if parentheses are present in s.
NumberStyles.AllowThousands 尽管组分隔符符号可以出现在 s中,但它前面只能有一个或多个0数字。Although the group separator symbol can appear in s, it can be preceded by only one or more 0 digits.
NumberStyles.AllowCurrencySymbol $ 元素。The $ element.

如果使用 NumberStyles.AllowHexSpecifier 标志,则 s 必须是不带前缀的十六进制值。If the NumberStyles.AllowHexSpecifier flag is used, s must be a hexadecimal value without a prefix. 例如,"F3" 分析成功,但 "0xF3" 不能。For example, "F3" parses successfully, but "0xF3" does not. style 中的唯一其他标志 NumberStyles.AllowLeadingWhiteNumberStyles.AllowTrailingWhiteThe only other flags that can be present in style are NumberStyles.AllowLeadingWhite and NumberStyles.AllowTrailingWhite. NumberStyles 枚举具有复合数字样式,NumberStyles.HexNumber,它包含两个空格标志。)(The NumberStyles enumeration has a composite number style, NumberStyles.HexNumber, that includes both white space flags.)

provider 参数是一个 IFormatProvider 实现,如 CultureInfo 对象或 NumberFormatInfo 对象,其 GetFormat 方法返回 NumberFormatInfo 对象。The provider parameter is an IFormatProvider implementation, such as a CultureInfo object or a NumberFormatInfo object, whose GetFormat method returns a NumberFormatInfo object. NumberFormatInfo 对象提供有关 s格式的区域性特定信息。The NumberFormatInfo object provides culture-specific information about the format of s.

另请参阅

TryParse(ReadOnlySpan<Char>, NumberStyles, IFormatProvider, Byte)

将指定样式和区域性特定格式的数字的范围表示形式转换为它的等效 ByteConverts the span representation of a number in a specified style and culture-specific format to its Byte equivalent. 一个指示转换是否成功的返回值。A return value indicates whether the conversion succeeded or failed.

public:
 static bool TryParse(ReadOnlySpan<char> s, System::Globalization::NumberStyles style, IFormatProvider ^ provider, [Runtime::InteropServices::Out] System::Byte % result);
public static bool TryParse (ReadOnlySpan<char> s, System.Globalization.NumberStyles style, IFormatProvider provider, out byte result);
static member TryParse : ReadOnlySpan<char> * System.Globalization.NumberStyles * IFormatProvider * byte -> bool
Public Shared Function TryParse (s As ReadOnlySpan(Of Char), style As NumberStyles, provider As IFormatProvider, ByRef result As Byte) As Boolean

参数

s
ReadOnlySpan<Char>

一个范围,包含表示要转换的数字的字符。A span containing the characters representing the number to convert. 该范围使用 Integer 样式来进行解释。The span is interpreted using the Integer style.

style
NumberStyles

枚举值的按位组合,用于指示可出现在 s 中的样式元素。A bitwise combination of enumeration values that indicates the style elements that can be present in s. 要指定的一个典型值为 IntegerA typical value to specify is Integer.

provider
IFormatProvider

一个对象,提供有关 s 的区域性特定格式设置信息。An object that supplies culture-specific formatting information about s. 如果 providernull,则使用当前区域性。If provider is null, the thread current culture is used.

result
Byte

当此方法返回时,如果转换成功,则包含与 s 中所含数字等效的 8 位无符号整数值;如果转换失败,则包含零。When this method returns, contains the 8-bit unsigned integer value equivalent to the number contained in s if the conversion succeeded, or zero if the conversion failed. 如果 s 参数为 nullEmpty、格式不正确,或者表示的数字小于 MinValue 或大于 MaxValue,则转换失败。The conversion fails if the s parameter is null or Empty, is not of the correct format, or represents a number less than MinValue or greater than MaxValue. 此参数未经初始化即进行传递;最初在 result 中提供的任何值都会被覆盖。This parameter is passed uninitialized; any value originally supplied in result will be overwritten.

返回

如果 true 成功转换,则为 s;否则为 falsetrue if s was converted successfully; otherwise, false.

适用于