String.Concat String.Concat String.Concat String.Concat Method

定义

连接 String 的一个或多个实例,或 String 的一个或多个实例的值的 Object 表示形式。Concatenates one or more instances of String, or the String representations of the values of one or more instances of Object.

重载

Concat(String, String, String, String) Concat(String, String, String, String) Concat(String, String, String, String) Concat(String, String, String, String)

连接 String 的四个指定实例。Concatenates four specified instances of String.

Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>)

连接四个指定的只读字符范围的字符串表示形式。Concatenates the string representations of four specified read-only character spans.

Concat(Object, Object, Object, Object) Concat(Object, Object, Object, Object) Concat(Object, Object, Object, Object) Concat(Object, Object, Object, Object)

将四个指定对象的字符串表示形式与可选变量长度参数列表中指定的任何对象串联起来。Concatenates the string representations of four specified objects and any objects specified in an optional variable length parameter list.

Concat(String, String, String) Concat(String, String, String) Concat(String, String, String) Concat(String, String, String)

连接 String 的三个指定实例。Concatenates three specified instances of String.

Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>)

连接三个指定的只读字符范围的字符串表示形式。Concatenates the string representations of three specified read-only character spans.

Concat(Object, Object, Object) Concat(Object, Object, Object) Concat(Object, Object, Object) Concat(Object, Object, Object)

连接三个指定对象的字符串表示形式。Concatenates the string representations of three specified objects.

Concat(Object, Object) Concat(Object, Object) Concat(Object, Object) Concat(Object, Object)

连接两个指定对象的字符串表示形式。Concatenates the string representations of two specified objects.

Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>)

连接两个指定的只读字符范围的字符串表示形式。Concatenates the string representations of two specified read-only character spans.

Concat(String[]) Concat(String[]) Concat(String[]) Concat(String[])

连接指定的 String 数组的元素。Concatenates the elements of a specified String array.

Concat(Object[]) Concat(Object[]) Concat(Object[]) Concat(Object[])

连接指定 Object 数组中的元素的字符串表示形式。Concatenates the string representations of the elements in a specified Object array.

Concat(Object) Concat(Object) Concat(Object) Concat(Object)

创建指定对象的字符串表示形式。Creates the string representation of a specified object.

Concat(IEnumerable<String>) Concat(IEnumerable<String>) Concat(IEnumerable<String>) Concat(IEnumerable<String>)

串联类型为 IEnumerable<T>String 构造集合的成员。Concatenates the members of a constructed IEnumerable<T> collection of type String.

Concat(String, String) Concat(String, String) Concat(String, String) Concat(String, String)

连接 String 的两个指定实例。Concatenates two specified instances of String.

Concat<T>(IEnumerable<T>) Concat<T>(IEnumerable<T>) Concat<T>(IEnumerable<T>) Concat<T>(IEnumerable<T>)

串联 IEnumerable<T> 实现的成员。Concatenates the members of an IEnumerable<T> implementation.

注解

备注

你还可以使用语言的+字符串串联运算符 (如在中C#, 或& +在 Visual Basic 中连接字符串)。You can also use your language's string concatenation operator, such as + in C#, or & and + in Visual Basic, to concatenate strings. 这两个编译器都将串连运算符转换为对的重载String.Concat之一的调用。Both compilers translate the concatenation operator into a call to one of the overloads of String.Concat.

Concat(String, String, String, String) Concat(String, String, String, String) Concat(String, String, String, String) Concat(String, String, String, String)

连接 String 的四个指定实例。Concatenates four specified instances of String.

public:
 static System::String ^ Concat(System::String ^ str0, System::String ^ str1, System::String ^ str2, System::String ^ str3);
public static string Concat (string str0, string str1, string str2, string str3);
static member Concat : string * string * string * string -> string
Public Shared Function Concat (str0 As String, str1 As String, str2 As String, str3 As String) As String

参数

str0
String String String String

要串联的第一个字符串。The first string to concatenate.

str1
String String String String

要串联的第二个字符串。The second string to concatenate.

str2
String String String String

要比较的第三个字符串。The third string to concatenate.

str3
String String String String

要比较的第四个字符串。The fourth string to concatenate.

返回

str0str1str2str3 的串联。The concatenation of str0, str1, str2, and str3.

示例

下面的示例定义一个包含四个字母的单词的数组, 并将其各个字母存储到字符串数组中, 以便对它们进行编码。The following example defines an array of four-letter words and stores their individual letters to a string array in order to scramble them. 然后, 它会Concat(String, String, String, String)调用方法来重新组合打乱的单词。It then calls the Concat(String, String, String, String) method to reassemble the scrambled words.

using System;
using System.Collections;

public class Example
{
   public static void Main()
   {
      const int WORD_SIZE = 4;
      
      // Define some 4-letter words to be scrambled.
      string[] words = { "home", "food", "game", "rest" };
      // Define two arrays equal to the number of letters in each word.
      double[] keys = new double[WORD_SIZE];
      string[] letters = new string[WORD_SIZE];
      // Initialize the random number generator.
      Random rnd = new Random();
      
      // Scramble each word.
      foreach (string word in words)
      {
         for (int ctr = 0; ctr < word.Length; ctr++)
         {
            // Populate the array of keys with random numbers.
            keys[ctr] = rnd.NextDouble();
            // Assign a letter to the array of letters.
            letters[ctr] = word[ctr].ToString();
         }   
         // Sort the array. 
         Array.Sort(keys, letters, 0, WORD_SIZE, Comparer.Default);      
         // Display the scrambled word.
         string scrambledWord = String.Concat(letters[0], letters[1], 
                                              letters[2], letters[3]);
         Console.WriteLine("{0} --> {1}", word, scrambledWord);
      } 
   }
}
// The example displays output like the following:
//       home --> mheo
//       food --> oodf
//       game --> aemg
//       rest --> trse
Imports System.Collections

Module Example
   Public Sub Main()
      Const WORD_SIZE As Integer = 4
      
      ' Define some 4-letter words to be scrambled.
      Dim words() As String = { "home", "food", "game", "rest" }
      ' Define two arrays equal to the number of letters in each word.
      Dim keys(WORD_SIZE) As Double
      Dim letters(WORD_SIZE) As String
      ' Initialize the random number generator.
      Dim rnd As New Random()
      
      ' Scramble each word.
      For Each word As String In words
         For ctr As Integer = 0 To word.Length - 1
            ' Populate the array of keys with random numbers.
            keys(ctr) = rnd.NextDouble()
            ' Assign a letter to the array of letters.
            letters(ctr) = word.Chars(ctr)
         Next   
         ' Sort the array. 
         Array.Sort(keys, letters, 0, WORD_SIZE, Comparer.Default)      
         ' Display the scrambled word.
         Dim scrambledWord As String = String.Concat(letters(0), letters(1), _
                                                     letters(2), letters(3))
         Console.WriteLine("{0} --> {1}", word, scrambledWord)
      Next 
   End Sub
End Module 
' The example displays output like the following:
'       home --> mheo
'       food --> oodf
'       game --> aemg
'       rest --> trse

注解

方法会连接str0 str1str2、和str3, 但不会添加任何分隔符。The method concatenates str0, str1, str2, and str3; it does not add any delimiters.

另请参阅

Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>)

连接四个指定的只读字符范围的字符串表示形式。Concatenates the string representations of four specified read-only character spans.

public:
 static System::String ^ Concat(ReadOnlySpan<char> str0, ReadOnlySpan<char> str1, ReadOnlySpan<char> str2, ReadOnlySpan<char> str3);
public static string Concat (ReadOnlySpan<char> str0, ReadOnlySpan<char> str1, ReadOnlySpan<char> str2, ReadOnlySpan<char> str3);
static member Concat : ReadOnlySpan<char> * ReadOnlySpan<char> * ReadOnlySpan<char> * ReadOnlySpan<char> -> string
Public Shared Function Concat (str0 As ReadOnlySpan(Of Char), str1 As ReadOnlySpan(Of Char), str2 As ReadOnlySpan(Of Char), str3 As ReadOnlySpan(Of Char)) As String

参数

str0
ReadOnlySpan<Char>

要连接的第一个只读字符范围。The first read-only character span to concatenate.

str1
ReadOnlySpan<Char>

要连接的第二个只读字符范围。The second read-only character span to concatenate.

str2
ReadOnlySpan<Char>

要连接的第三个只读字符范围。The third read-only character span to concatenate.

str3
ReadOnlySpan<Char>

要连接的第四个只读字符范围。The fourth read-only character span to concatenate.

返回

str0str1str2str3 的值的已连接字符串表示形式。The concatenated string representations of the values of str0, str1, str2 and str3.

Concat(Object, Object, Object, Object) Concat(Object, Object, Object, Object) Concat(Object, Object, Object, Object) Concat(Object, Object, Object, Object)

重要

此 API 不符合 CLS。

将四个指定对象的字符串表示形式与可选变量长度参数列表中指定的任何对象串联起来。Concatenates the string representations of four specified objects and any objects specified in an optional variable length parameter list.

public:
 static System::String ^ Concat(System::Object ^ arg0, System::Object ^ arg1, System::Object ^ arg2, System::Object ^ arg3);
[System.CLSCompliant(false)]
public static string Concat (object arg0, object arg1, object arg2, object arg3);
static member Concat : obj * obj * obj * obj -> string
Public Shared Function Concat (arg0 As Object, arg1 As Object, arg2 As Object, arg3 As Object) As String

参数

arg0
Object Object Object Object

要连接的第一个对象。The first object to concatenate.

arg1
Object Object Object Object

要连接的第二个对象。The second object to concatenate.

arg2
Object Object Object Object

要连接的第三个对象。The third object to concatenate.

arg3
Object Object Object Object

要连接的第四个对象。The fourth object to concatenate.

返回

参数列表中的每个值的连接字符串表示形式。The concatenated string representation of each value in the parameter list.

示例

下面的示例演示如何使用Concat(Object, Object, Object, Object)方法连接变量参数的列表。The following example illustrates the use of the Concat(Object, Object, Object, Object) method to concatenate a list of variable parameters. 在这种情况下, 将调用方法并带有九个参数。In this case, the method is called with nine parameters.

using System;
using System.Collections;

public class Example
{
   public static void Main()
   {
      const int WORD_SIZE = 4;
      
      // Define some 4-letter words to be scrambled.
      string[] words = { "home", "food", "game", "rest" };
      // Define two arrays equal to the number of letters in each word.
      double[] keys = new double[WORD_SIZE];
      string[] letters = new string[WORD_SIZE];
      // Initialize the random number generator.
      Random rnd = new Random();
      
      // Scramble each word.
      foreach (string word in words)
      {
         for (int ctr = 0; ctr < word.Length; ctr++)
         {
            // Populate the array of keys with random numbers.
            keys[ctr] = rnd.NextDouble();
            // Assign a letter to the array of letters.
            letters[ctr] = word[ctr].ToString();
         }   
         // Sort the array. 
         Array.Sort(keys, letters, 0, WORD_SIZE, Comparer.Default);      
         // Display the scrambled word.
         string scrambledWord = String.Concat(letters[0], letters[1], 
                                              letters[2], letters[3]);
         Console.WriteLine("{0} --> {1}", word, scrambledWord);
      } 
   }
}
// The example displays output like the following:
//       home --> mheo
//       food --> oodf
//       game --> aemg
//       rest --> trse
Imports System.Collections

Module Example
   Public Sub Main()
      Const WORD_SIZE As Integer = 4
      
      ' Define some 4-letter words to be scrambled.
      Dim words() As String = { "home", "food", "game", "rest" }
      ' Define two arrays equal to the number of letters in each word.
      Dim keys(WORD_SIZE) As Double
      Dim letters(WORD_SIZE) As String
      ' Initialize the random number generator.
      Dim rnd As New Random()
      
      ' Scramble each word.
      For Each word As String In words
         For ctr As Integer = 0 To word.Length - 1
            ' Populate the array of keys with random numbers.
            keys(ctr) = rnd.NextDouble()
            ' Assign a letter to the array of letters.
            letters(ctr) = word.Chars(ctr)
         Next   
         ' Sort the array. 
         Array.Sort(keys, letters, 0, WORD_SIZE, Comparer.Default)      
         ' Display the scrambled word.
         Dim scrambledWord As String = String.Concat(letters(0), letters(1), _
                                                     letters(2), letters(3))
         Console.WriteLine("{0} --> {1}", word, scrambledWord)
      Next 
   End Sub
End Module 
' The example displays output like the following:
'       home --> mheo
'       food --> oodf
'       game --> aemg
'       rest --> trse

注解

备注

此 API 不兼容 CLS。This API is not CLS-compliant. 符合 CLS 的替代方法是 String.Concat(Object[])The CLS-compliant alternative is String.Concat(Object[]). C#和 Visual Basic 编译器会自动将对此方法的调用解析为对String.Concat(Object[])的调用。The C# and Visual Basic compilers automatically resolve a call to this method as a call to String.Concat(Object[]).

方法通过调用其无参数ToString方法连接参数列表中的每个对象, 而不会添加任何分隔符。The method concatenates each object in the parameter list by calling its parameterless ToString method; it does not add any delimiters.

String.Empty用于替代任何空参数。String.Empty is used in place of any null argument.

备注

Concat方法的最后一个参数是要连接的一个或多个附加对象的以逗号分隔的可选列表。The last parameter of the Concat method is an optional comma-delimited list of one or more additional objects to concatenate.

调用方说明

此方法使用vararg关键字进行标记, 这意味着它支持数量可变的参数。This method is marked with the vararg keyword, which means that it supports a variable number of parameters. 方法可以从视觉对象C++调用, 但是不能从或 Visual Basic 代码C#中调用。The method can be called from Visual C++, but it cannot be called from C# or Visual Basic code. C#和 Visual Basic 编译器将调用Concat(Object, Object, Object, Object) Concat(Object[])解析为对的调用。The C# and Visual Basic compilers resolve calls to Concat(Object, Object, Object, Object) as calls to Concat(Object[]).

Concat(String, String, String) Concat(String, String, String) Concat(String, String, String) Concat(String, String, String)

连接 String 的三个指定实例。Concatenates three specified instances of String.

public:
 static System::String ^ Concat(System::String ^ str0, System::String ^ str1, System::String ^ str2);
public static string Concat (string str0, string str1, string str2);
static member Concat : string * string * string -> string
Public Shared Function Concat (str0 As String, str1 As String, str2 As String) As String

参数

str0
String String String String

要串联的第一个字符串。The first string to concatenate.

str1
String String String String

要串联的第二个字符串。The second string to concatenate.

str2
String String String String

要比较的第三个字符串。The third string to concatenate.

返回

str0str1str2 的串联。The concatenation of str0, str1, and str2.

示例

下面的示例使用Concat方法连接三个字符串并显示结果。The following example uses the Concat method to concatenate three strings and displays the result.

using namespace System;

void main()
{
   String^ s1 = "We went to a bookstore, ";
   String^ s2 = "a movie, ";
   String^ s3 = "and a restaurant.";

   String^ s = String::Concat(s1, s2, s3);
   Console::WriteLine(s);
}
// The example displays the following output:
//      We went to a bookstore, a movie, and a restaurant. 
using System;

public class Example
{
   public static void Main()
   {
      String s1 = "We went to a bookstore, ";
      String s2 = "a movie, ";
      String s3 = "and a restaurant.";

      var s = String.Concat(s1, s2, s3);
      Console.WriteLine(s);
   }
}
// The example displays the following output:
//      We went to a bookstore, a movie, and a restaurant. 
Imports System

Public Module Example
   Public Sub Main()
      Dim s1 As String = "We went to a bookstore, "
      Dim s2 As String = "a movie, "
      Dim s3 As String = "and a restaurant."

      Dim s = String.Concat(s1, s2, s3)
      Console.WriteLine(s)
   End Sub
End Module
' The example displays the following output:
'      We went to a bookstore, a movie, and a restaurant. 

注解

方法连接str0str1str2, 而不添加任何分隔符。The method concatenates str0, str1, and str2; it does not add any delimiters.

另请参阅

Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>)

连接三个指定的只读字符范围的字符串表示形式。Concatenates the string representations of three specified read-only character spans.

public:
 static System::String ^ Concat(ReadOnlySpan<char> str0, ReadOnlySpan<char> str1, ReadOnlySpan<char> str2);
public static string Concat (ReadOnlySpan<char> str0, ReadOnlySpan<char> str1, ReadOnlySpan<char> str2);
static member Concat : ReadOnlySpan<char> * ReadOnlySpan<char> * ReadOnlySpan<char> -> string
Public Shared Function Concat (str0 As ReadOnlySpan(Of Char), str1 As ReadOnlySpan(Of Char), str2 As ReadOnlySpan(Of Char)) As String

参数

str0
ReadOnlySpan<Char>

要连接的第一个只读字符范围。The first read-only character span to concatenate.

str1
ReadOnlySpan<Char>

要连接的第二个只读字符范围。The second read-only character span to concatenate.

str2
ReadOnlySpan<Char>

要连接的第三个只读字符范围。The third read-only character span to concatenate.

返回

str0str1str2 的值的已连接字符串表示形式。The concatenated string representations of the values of str0, str1 and str2.

Concat(Object, Object, Object) Concat(Object, Object, Object) Concat(Object, Object, Object) Concat(Object, Object, Object)

连接三个指定对象的字符串表示形式。Concatenates the string representations of three specified objects.

public:
 static System::String ^ Concat(System::Object ^ arg0, System::Object ^ arg1, System::Object ^ arg2);
public static string Concat (object arg0, object arg1, object arg2);
static member Concat : obj * obj * obj -> string
Public Shared Function Concat (arg0 As Object, arg1 As Object, arg2 As Object) As String

参数

arg0
Object Object Object Object

要连接的第一个对象。The first object to concatenate.

arg1
Object Object Object Object

要连接的第二个对象。The second object to concatenate.

arg2
Object Object Object Object

要连接的第三个对象。The third object to concatenate.

返回

arg0arg1arg2 的值的串联字符串表示形式。The concatenated string representations of the values of arg0, arg1, and arg2.

示例

下面的示例演示Concat方法。The following example demonstrates the Concat method.

using namespace System;

int main()
{
   int i = -123;
   Object^ o = i;
   array<Object^>^objs = { -123, -456, -789};
   Console::WriteLine("Concatenate 1, 2, and 3 objects:");
   Console::WriteLine("1) {0}", String::Concat(o));
   Console::WriteLine("2) {0}", String::Concat(o, o));
   Console::WriteLine("3) {0}", String::Concat(o, o, o));
   
   Console::WriteLine("\nConcatenate 4 objects and a variable length parameter list:" );
   Console::WriteLine("4) {0}", String::Concat(o, o, o, o));
   Console::WriteLine("5) {0}", String::Concat( o, o, o, o, o));
   Console::WriteLine("\nConcatenate a 3-element object array:");
   Console::WriteLine("6) {0}", String::Concat(objs));
}
// The example displays the following output:
//    Concatenate 1, 2, and 3 objects:
//    1) -123
//    2) -123-123
//    3) -123-123-123
//    
//    Concatenate 4 objects and a variable length parameter list:
//    4) -123-123-123-123
//    5) -123-123-123-123-123
//    
//    Concatenate a 3-element object array:
//    6) -123-456-789
using System;

class stringConcat5 {
    public static void Main() {
    int i = -123;
    Object o = i;
    Object[] objs = new Object[] {-123, -456, -789};

    Console.WriteLine("Concatenate 1, 2, and 3 objects:");
    Console.WriteLine("1) {0}", String.Concat(o));
    Console.WriteLine("2) {0}", String.Concat(o, o));
    Console.WriteLine("3) {0}", String.Concat(o, o, o));

    Console.WriteLine("\nConcatenate 4 objects and a variable length parameter list:");
    Console.WriteLine("4) {0}", String.Concat(o, o, o, o));
    Console.WriteLine("5) {0}", String.Concat(o, o, o, o, o));

    Console.WriteLine("\nConcatenate a 3-element object array:");
    Console.WriteLine("6) {0}", String.Concat(objs));
    }
}
// The example displays the following output:
//    Concatenate 1, 2, and 3 objects:
//    1) -123
//    2) -123-123
//    3) -123-123-123
//    
//    Concatenate 4 objects and a variable length parameter list:
//    4) -123-123-123-123
//    5) -123-123-123-123-123
//    
//    Concatenate a 3-element object array:
//    6) -123-456-789
Class stringConcat5
   Public Shared Sub Main()
      Dim i As Integer = - 123
      Dim o As [Object] = i
      Dim objs() As [Object] = {-123, -456, -789}
      
      Console.WriteLine("Concatenate 1, 2, and 3 objects:")
      Console.WriteLine("1) {0}", [String].Concat(o))
      Console.WriteLine("2) {0}", [String].Concat(o, o))
      Console.WriteLine("3) {0}", [String].Concat(o, o, o))
      
      Console.WriteLine(vbCrLf & "Concatenate 4 objects and a variable length parameter list:")
      Console.WriteLine("4) {0}", String.Concat(o, o, o, o))
      Console.WriteLine("5) {0}", String.Concat(o, o, o, o, o))
      
      Console.WriteLine(vbCrLf & "Concatenate a 3-element object array:")
      Console.WriteLine("6) {0}", [String].Concat(objs))
   End Sub
End Class
'The example displays the following output:
'    Concatenate 1, 2, and 3 objects:
'    1) -123
'    2) -123-123
'    3) -123-123-123
'    
'    Concatenate 4 objects and a variable length parameter list:
'    4) -123-123-123-123
'    5) -123-123-123-123-123
'         
'    Concatenate a 3-element object array:
'    6) -123-456-789

注解

方法通过调用arg0arg1个对象arg2的无参数ToString方法连接、和, 而不添加任何分隔符。The method concatenates arg0, arg1, and arg2 by calling the parameterless ToString method of each object; it does not add any delimiters.

String.Empty用于替代任何空参数。String.Empty is used in place of any null argument.

另请参阅

Concat(Object, Object) Concat(Object, Object) Concat(Object, Object) Concat(Object, Object)

连接两个指定对象的字符串表示形式。Concatenates the string representations of two specified objects.

public:
 static System::String ^ Concat(System::Object ^ arg0, System::Object ^ arg1);
public static string Concat (object arg0, object arg1);
static member Concat : obj * obj -> string
Public Shared Function Concat (arg0 As Object, arg1 As Object) As String

参数

arg0
Object Object Object Object

要连接的第一个对象。The first object to concatenate.

arg1
Object Object Object Object

要连接的第二个对象。The second object to concatenate.

返回

arg0arg1 的值的串联字符串表示形式。The concatenated string representations of the values of arg0 and arg1.

示例

下面的示例演示Concat方法。The following example demonstrates the Concat method.

using namespace System;

int main()
{
   int i = -123;
   Object^ o = i;
   array<Object^>^objs = { -123, -456, -789};
   Console::WriteLine("Concatenate 1, 2, and 3 objects:");
   Console::WriteLine("1) {0}", String::Concat(o));
   Console::WriteLine("2) {0}", String::Concat(o, o));
   Console::WriteLine("3) {0}", String::Concat(o, o, o));
   
   Console::WriteLine("\nConcatenate 4 objects and a variable length parameter list:" );
   Console::WriteLine("4) {0}", String::Concat(o, o, o, o));
   Console::WriteLine("5) {0}", String::Concat( o, o, o, o, o));
   Console::WriteLine("\nConcatenate a 3-element object array:");
   Console::WriteLine("6) {0}", String::Concat(objs));
}
// The example displays the following output:
//    Concatenate 1, 2, and 3 objects:
//    1) -123
//    2) -123-123
//    3) -123-123-123
//    
//    Concatenate 4 objects and a variable length parameter list:
//    4) -123-123-123-123
//    5) -123-123-123-123-123
//    
//    Concatenate a 3-element object array:
//    6) -123-456-789
using System;

class stringConcat5 {
    public static void Main() {
    int i = -123;
    Object o = i;
    Object[] objs = new Object[] {-123, -456, -789};

    Console.WriteLine("Concatenate 1, 2, and 3 objects:");
    Console.WriteLine("1) {0}", String.Concat(o));
    Console.WriteLine("2) {0}", String.Concat(o, o));
    Console.WriteLine("3) {0}", String.Concat(o, o, o));

    Console.WriteLine("\nConcatenate 4 objects and a variable length parameter list:");
    Console.WriteLine("4) {0}", String.Concat(o, o, o, o));
    Console.WriteLine("5) {0}", String.Concat(o, o, o, o, o));

    Console.WriteLine("\nConcatenate a 3-element object array:");
    Console.WriteLine("6) {0}", String.Concat(objs));
    }
}
// The example displays the following output:
//    Concatenate 1, 2, and 3 objects:
//    1) -123
//    2) -123-123
//    3) -123-123-123
//    
//    Concatenate 4 objects and a variable length parameter list:
//    4) -123-123-123-123
//    5) -123-123-123-123-123
//    
//    Concatenate a 3-element object array:
//    6) -123-456-789
Class stringConcat5
   Public Shared Sub Main()
      Dim i As Integer = - 123
      Dim o As [Object] = i
      Dim objs() As [Object] = {-123, -456, -789}
      
      Console.WriteLine("Concatenate 1, 2, and 3 objects:")
      Console.WriteLine("1) {0}", [String].Concat(o))
      Console.WriteLine("2) {0}", [String].Concat(o, o))
      Console.WriteLine("3) {0}", [String].Concat(o, o, o))
      
      Console.WriteLine(vbCrLf & "Concatenate 4 objects and a variable length parameter list:")
      Console.WriteLine("4) {0}", String.Concat(o, o, o, o))
      Console.WriteLine("5) {0}", String.Concat(o, o, o, o, o))
      
      Console.WriteLine(vbCrLf & "Concatenate a 3-element object array:")
      Console.WriteLine("6) {0}", [String].Concat(objs))
   End Sub
End Class
'The example displays the following output:
'    Concatenate 1, 2, and 3 objects:
'    1) -123
'    2) -123-123
'    3) -123-123-123
'    
'    Concatenate 4 objects and a variable length parameter list:
'    4) -123-123-123-123
'    5) -123-123-123-123-123
'         
'    Concatenate a 3-element object array:
'    6) -123-456-789

注解

arg0方法通过ToString调用和arg1arg1无参数方法连接和, 而不添加任何分隔符arg0The method concatenates arg0 and arg1 by calling the parameterless ToString method of arg0 and arg1; it does not add any delimiters.

String.Empty用于替代任何空参数。String.Empty is used in place of any null argument.

如果任何一个参数为数组引用, 则该方法将连接一个表示该数组的字符串, 而不是其成员 (例如, "System.string []")。If either of the arguments is an array reference, the method concatenates a string representing that array, instead of its members (for example, "System.String[]").

另请参阅

Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>) Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>)

连接两个指定的只读字符范围的字符串表示形式。Concatenates the string representations of two specified read-only character spans.

public:
 static System::String ^ Concat(ReadOnlySpan<char> str0, ReadOnlySpan<char> str1);
public static string Concat (ReadOnlySpan<char> str0, ReadOnlySpan<char> str1);
static member Concat : ReadOnlySpan<char> * ReadOnlySpan<char> -> string
Public Shared Function Concat (str0 As ReadOnlySpan(Of Char), str1 As ReadOnlySpan(Of Char)) As String

参数

str0
ReadOnlySpan<Char>

要连接的第一个只读字符范围。The first read-only character span to concatenate.

str1
ReadOnlySpan<Char>

要连接的第二个只读字符范围。The second read-only character span to concatenate.

返回

str0str1 的值的串联字符串表示形式。The concatenated string representations of the values of str0 and str1.

Concat(String[]) Concat(String[]) Concat(String[]) Concat(String[])

重要

此 API 不符合 CLS。

连接指定的 String 数组的元素。Concatenates the elements of a specified String array.

public:
 static System::String ^ Concat(... cli::array <System::String ^> ^ values);
[System.CLSCompliant(false)]
public static string Concat (params string[] values);
static member Concat : string[] -> string
Public Shared Function Concat (ParamArray values As String()) As String

参数

values
String[]

字符串实例的数组。An array of string instances.

返回

values 的串联元素。The concatenated elements of values.

异常

示例

下面的示例演示如何将Concat方法String用于数组。The following example demonstrates the use of the Concat method with a String array.

using namespace System;

int main()
{
   
   // Make an array of strings. Note that we have included spaces.
   array<String^>^s = { "hello ", "and ", "welcome ", "to ",
                        "this ", "demo! "};
   
   // Put all the strings together.
   Console::WriteLine( String::Concat(s) );
   
   // Sort the strings, and put them together.
   Array::Sort( s );
   Console::WriteLine( String::Concat(s));
}
// The example displays the following output:
//       hello and welcome to this demo!
//       and demo! hello this to welcome
using System;

public class Example
{
    public static void Main()
    {
        // Make an array of strings. Note that we have included spaces.
        string [] s = { "hello ", "and ", "welcome ", "to ",
                        "this ", "demo! " };

        // Put all the strings together.
        Console.WriteLine(string.Concat(s));

        // Sort the strings, and put them together.
        Array.Sort(s);
        Console.WriteLine(string.Concat(s));
    }
}
// The example displays the following output:
//       hello and welcome to this demo!
//       and demo! hello this to welcome
Public Class Example
    Public Shared Sub Main()
        ' Make an array of strings. Note that we have included spaces.
        Dim s As String() = { "hello ", "and ", "welcome ", "to ",
                              "this ", "demo! "}

        ' Put all the strings together.
        Console.WriteLine(String.Concat(s))
        
        ' Sort the strings, and put them together.
        Array.Sort(s)
        Console.WriteLine(String.Concat(s))
    End Sub
End Class
' The example displays the following output:
'       hello and welcome to this demo!
'       and demo! hello this to welcome

注解

此方法连接中values的每个对象; 它不添加任何分隔符。The method concatenates each object in values; it does not add any delimiters.

Empty字符串用于替代数组中的任何 null 对象。An Empty string is used in place of any null object in the array.

另请参阅

Concat(Object[]) Concat(Object[]) Concat(Object[]) Concat(Object[])

连接指定 Object 数组中的元素的字符串表示形式。Concatenates the string representations of the elements in a specified Object array.

public:
 static System::String ^ Concat(... cli::array <System::Object ^> ^ args);
public static string Concat (params object[] args);
static member Concat : obj[] -> string
Public Shared Function Concat (ParamArray args As Object()) As String

参数

args
Object[]

一个对象数组,其中包含要连接的元素。An object array that contains the elements to concatenate.

返回

args 中元素的值的串联字符串表示形式。The concatenated string representations of the values of the elements in args.

异常

示例

下面的示例演示如何将Concat方法Object用于数组。The following example demonstrates the use of the Concat method with an Object array.

using System;

public class ConcatTest {
    public static void Main() {
        // Create a group of objects.
        Test1 t1 = new Test1();
        Test2 t2 = new Test2();
        int i = 16;
        string s = "Demonstration";

        // Place the objects in an array.
        object [] o = { t1, i, t2, s };

        // Concatenate the objects together as a string. To do this,
        // the ToString method of each of the objects is called.
        Console.WriteLine(string.Concat(o));
    }
}

// Create two empty test classes.
class Test1 {
}

class Test2 {
}
// The example displays the following output:
//       Test116Test2Demonstration
Imports System



Public Class ConcatTest
    
    Public Shared Sub Main()
        Dim t1 As New Test1()
        Dim t2 As New Test2()
        Dim i As Integer = 16
        Dim s As String = "Demonstration"
        Dim o As Object() = {t1, i, t2, s}
        
        ' create a group of objects
        
        ' place the objects in an array
        
        ' concatenate the objects together as a string. To do this,
        ' the ToString method in the objects is called
        Console.WriteLine(String.Concat(o))
    End Sub 'Main
End Class 'ConcatTest


' imagine these test classes are full-fledged objects...
Class Test1
End Class 'Test1

Class Test2
End Class 'Test2

注解

方法通过调用该对象的args无参数ToString方法来连接中的每个对象, 而不会添加任何分隔符。The method concatenates each object in args by calling the parameterless ToString method of that object; it does not add any delimiters.

String.Empty用于替代数组中的任何 null 对象。String.Empty is used in place of any null object in the array.

调用方说明

C++代码不会调用此方法。This method is not called by C++ code. C++编译器解析对Concat的调用, 该调用具有四个或更多对象参数Concat(Object, Object, Object, Object)作为对的调用。The C++ compiler resolves calls to Concat that have four or more object parameters as a call to Concat(Object, Object, Object, Object).

另请参阅

Concat(Object) Concat(Object) Concat(Object) Concat(Object)

创建指定对象的字符串表示形式。Creates the string representation of a specified object.

public:
 static System::String ^ Concat(System::Object ^ arg0);
public static string Concat (object arg0);
static member Concat : obj -> string
Public Shared Function Concat (arg0 As Object) As String

参数

arg0
Object Object Object Object

要表示的对象,或 nullThe object to represent, or null.

返回

arg0 的值的字符串表示形式,如果 Emptyarg0,则为 nullThe string representation of the value of arg0, or Empty if arg0 is null.

示例

下面的示例演示Concat方法。The following example demonstrates the Concat method.

using namespace System;

int main()
{
   int i = -123;
   Object^ o = i;
   array<Object^>^objs = { -123, -456, -789};
   Console::WriteLine("Concatenate 1, 2, and 3 objects:");
   Console::WriteLine("1) {0}", String::Concat(o));
   Console::WriteLine("2) {0}", String::Concat(o, o));
   Console::WriteLine("3) {0}", String::Concat(o, o, o));
   
   Console::WriteLine("\nConcatenate 4 objects and a variable length parameter list:" );
   Console::WriteLine("4) {0}", String::Concat(o, o, o, o));
   Console::WriteLine("5) {0}", String::Concat( o, o, o, o, o));
   Console::WriteLine("\nConcatenate a 3-element object array:");
   Console::WriteLine("6) {0}", String::Concat(objs));
}
// The example displays the following output:
//    Concatenate 1, 2, and 3 objects:
//    1) -123
//    2) -123-123
//    3) -123-123-123
//    
//    Concatenate 4 objects and a variable length parameter list:
//    4) -123-123-123-123
//    5) -123-123-123-123-123
//    
//    Concatenate a 3-element object array:
//    6) -123-456-789
using System;

class stringConcat5 {
    public static void Main() {
    int i = -123;
    Object o = i;
    Object[] objs = new Object[] {-123, -456, -789};

    Console.WriteLine("Concatenate 1, 2, and 3 objects:");
    Console.WriteLine("1) {0}", String.Concat(o));
    Console.WriteLine("2) {0}", String.Concat(o, o));
    Console.WriteLine("3) {0}", String.Concat(o, o, o));

    Console.WriteLine("\nConcatenate 4 objects and a variable length parameter list:");
    Console.WriteLine("4) {0}", String.Concat(o, o, o, o));
    Console.WriteLine("5) {0}", String.Concat(o, o, o, o, o));

    Console.WriteLine("\nConcatenate a 3-element object array:");
    Console.WriteLine("6) {0}", String.Concat(objs));
    }
}
// The example displays the following output:
//    Concatenate 1, 2, and 3 objects:
//    1) -123
//    2) -123-123
//    3) -123-123-123
//    
//    Concatenate 4 objects and a variable length parameter list:
//    4) -123-123-123-123
//    5) -123-123-123-123-123
//    
//    Concatenate a 3-element object array:
//    6) -123-456-789
Class stringConcat5
   Public Shared Sub Main()
      Dim i As Integer = - 123
      Dim o As [Object] = i
      Dim objs() As [Object] = {-123, -456, -789}
      
      Console.WriteLine("Concatenate 1, 2, and 3 objects:")
      Console.WriteLine("1) {0}", [String].Concat(o))
      Console.WriteLine("2) {0}", [String].Concat(o, o))
      Console.WriteLine("3) {0}", [String].Concat(o, o, o))
      
      Console.WriteLine(vbCrLf & "Concatenate 4 objects and a variable length parameter list:")
      Console.WriteLine("4) {0}", String.Concat(o, o, o, o))
      Console.WriteLine("5) {0}", String.Concat(o, o, o, o, o))
      
      Console.WriteLine(vbCrLf & "Concatenate a 3-element object array:")
      Console.WriteLine("6) {0}", [String].Concat(objs))
   End Sub
End Class
'The example displays the following output:
'    Concatenate 1, 2, and 3 objects:
'    1) -123
'    2) -123-123
'    3) -123-123-123
'    
'    Concatenate 4 objects and a variable length parameter list:
'    4) -123-123-123-123
'    5) -123-123-123-123-123
'         
'    Concatenate a 3-element object array:
'    6) -123-456-789

注解

方法通过调用arg0其无参数ToString的方法将表示为字符串。 Concat(Object)The Concat(Object) method represents arg0 as a string by calling its parameterless ToString method.

另请参阅

Concat(IEnumerable<String>) Concat(IEnumerable<String>) Concat(IEnumerable<String>) Concat(IEnumerable<String>)

串联类型为 IEnumerable<T>String 构造集合的成员。Concatenates the members of a constructed IEnumerable<T> collection of type String.

public:
 static System::String ^ Concat(System::Collections::Generic::IEnumerable<System::String ^> ^ values);
[System.Runtime.InteropServices.ComVisible(false)]
public static string Concat (System.Collections.Generic.IEnumerable<string> values);
static member Concat : seq<string> -> string
Public Shared Function Concat (values As IEnumerable(Of String)) As String

参数

values
IEnumerable<String>

一个集合对象,该对象实现 IEnumerable<T>,且其泛型类型参数为 StringA collection object that implements IEnumerable<T> and whose generic type argument is String.

返回

values 中的串联字符串;如果 values 为空 IEnumerable(Of String),则为 EmptyThe concatenated strings in values, or Empty if values is an empty IEnumerable(Of String).

异常

示例

下面的示例使用埃拉托色 of 尼斯筛法算法来计算小于或等于100的质数。The following example uses the Sieve of Eratosthenes algorithm to calculate the prime numbers that are less than or equal to 100. 它将结果分配给List<T>类型String的对象, 然后将该对象传递给Concat(IEnumerable<String>)方法。It assigns the result to a List<T> object of type String, which it then passes to the Concat(IEnumerable<String>) method.

using System;
using System.Collections.Generic;

public class Example
{
   public static void Main()
   {
      int maxPrime = 100;
      IEnumerable<String> primeList = GetPrimes(maxPrime);
      Console.WriteLine("Primes less than {0}:", maxPrime);
      Console.WriteLine("   {0}", String.Concat(primeList));
   }

   private static IEnumerable<String> GetPrimes(int maxPrime)
   {
      Array values = Array.CreateInstance(typeof(int), 
                              new int[] { maxPrime - 1}, new int[] { 2 }); 
      // Use Sieve of Erathsthenes to determine prime numbers.
      for (int ctr = values.GetLowerBound(0); ctr <= (int) Math.Ceiling(Math.Sqrt(values.GetUpperBound(0))); ctr++)
      {
                           
         if ((int) values.GetValue(ctr) == 1) continue;
         
         for (int multiplier = ctr; multiplier <=  maxPrime / 2; multiplier++)
            if (ctr * multiplier <= maxPrime)
               values.SetValue(1, ctr * multiplier);
      }      
      
      List<String> primes = new List<String>();
      for (int ctr = values.GetLowerBound(0); ctr <= values.GetUpperBound(0); ctr++)
         if ((int) values.GetValue(ctr) == 0) 
            primes.Add(ctr.ToString() + " ");
      return primes;
   }   
}
// The example displays the following output:
//    Primes less than 100:
//       2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97
Imports System.Collections.Generic

Module Example
   Public Sub Main()
      Dim maxPrime As Integer = 100
      Dim primeList As IEnumerable(Of String) = GetPrimes(maxPrime)
      Console.WriteLine("Primes less than {0}:", maxPrime)
      Console.WriteLine("   {0}", String.Concat(primeList))
   End Sub
   
   Private Function GetPrimes(maxPrime As Integer) As IEnumerable(Of String)
      Dim values As Array = Array.CreateInstance(GetType(Integer), _
                              New Integer() { maxPrime - 1}, New Integer(){ 2 }) 
      ' Use Sieve of Erathsthenes to determine prime numbers.
      For ctr As Integer = values.GetLowerBound(0) To _
                           CInt(Math.Ceiling(Math.Sqrt(values.GetUpperBound(0))))
         If CInt(values.GetValue(ctr)) = 1 Then Continue For
         
         For multiplier As Integer = ctr To maxPrime \ 2
            If ctr * multiplier <= maxPrime Then values.SetValue(1, ctr * multiplier)
         Next   
      Next      
      
      Dim primes As New List(Of String)
      For ctr As Integer = values.GetLowerBound(0) To values.GetUpperBound(0)
         If CInt(values.GetValue(ctr)) = 0 Then primes.Add(ctr.ToString() + " ")
      Next            
      Return primes
   End Function   
End Module
' The example displays the following output:
'    Primes less than 100:
'       2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97

注解

此方法连接中values的每个对象; 它不添加任何分隔符。The method concatenates each object in values; it does not add any delimiters. 若要指定每个成员values之间的分隔符, 请Join(String, IEnumerable<String>)调用方法。To specify a delimiter between each member of values, call the Join(String, IEnumerable<String>) method.

字符串用于替换中values的任何 null 元素。 EmptyAn Empty string is used in place of any null element in values.

如果 values ,则为 IEnumerable(Of String),则此方法返回 String.EmptyIf values is an empty IEnumerable(Of String), the method returns String.Empty. 如果valuesnull ,则该方法ArgumentNullException将引发异常。If values is null, the method throws an ArgumentNullException exception.

Concat(IEnumerable<String>)是一种简便方法, 使您可以连接IEnumerable(Of String)集合中的每个元素, 而无需先将元素转换为字符串数组。Concat(IEnumerable<String>) is a convenience method that lets you concatenate each element in an IEnumerable(Of String) collection without first converting the elements to a string array. 它对语言集成查询 (LINQ) 查询表达式特别有用。It is particularly useful with Language-Integrated Query (LINQ) query expressions. 下面的示例将包含List(Of String)字母表的大写或小写字母的对象传递给 lambda 表达式, 该表达式选择等于或大于特定字母的字母 (本例中为 "M")。The following example passes a List(Of String) object that contains either the uppercase or lowercase letters of the alphabet to a lambda expression that selects letters that are equal to or greater than a particular letter (which, in the example, is "M"). 方法返回Enumerable.WhereIEnumerable(Of String)集合传递给方法,Concat(IEnumerable<String>)以单个字符串的形式显示结果。The IEnumerable(Of String) collection that is returned by the Enumerable.Where method is passed to the Concat(IEnumerable<String>) method to display the result as a single string.

using System;
using System.Collections.Generic;
using System.Linq;

public class Example
{
   public static void Main()
   {
      string output = String.Concat( GetAlphabet(true).Where( letter => 
                      letter.CompareTo("M") >= 0));
      Console.WriteLine(output);  
   }

   private static List<string> GetAlphabet(bool upper)
   {
      List<string> alphabet = new List<string>();
      int charValue = upper ? 65 : 97;
      for (int ctr = 0; ctr <= 25; ctr++)
         alphabet.Add(Convert.ToChar(charValue + ctr).ToString());
      return alphabet; 
   }
}
// The example displays the following output:
//      MNOPQRSTUVWXYZ
Imports System.Collections.Generic
Imports System.Linq

Module modMain
   Public Sub Main()
      Dim output As String = String.Concat(GetAlphabet(true).Where(Function(letter) _
                                                         letter >= "M"))
        
      Console.WriteLine(output)                                     
   End Sub
   
   Private Function GetAlphabet(upper As Boolean) As List(Of String)
      Dim alphabet As New List(Of String)
      Dim charValue As Integer = CInt(IIf(upper, 65, 97))
      For ctr As Integer = 0 To 25
         alphabet.Add(ChrW(charValue + ctr).ToString())
      Next
      Return alphabet 
   End Function
End Module
' The example displays the following output:
'       MNOPQRSTUVWXYZ

Concat(String, String) Concat(String, String) Concat(String, String) Concat(String, String)

连接 String 的两个指定实例。Concatenates two specified instances of String.

public:
 static System::String ^ Concat(System::String ^ str0, System::String ^ str1);
public static string Concat (string str0, string str1);
static member Concat : string * string -> string
Public Shared Function Concat (str0 As String, str1 As String) As String

参数

str0
String String String String

要串联的第一个字符串。The first string to concatenate.

str1
String String String String

要串联的第二个字符串。The second string to concatenate.

返回

str0str1 的串联。The concatenation of str0 and str1.

示例

下面的示例将用户的名字、中间名和姓氏连接起来。The following example concatenates a person's first, middle, and last name.

using namespace System;
int main()
{
   
   // we want to simply quickly add this person's name together
   String^ fName = "Simon";
   String^ mName = "Jake";
   String^ lName = "Harrows";
   
   // because we want a name to appear with a space in between each name, 
   // put a space on the front of the middle, and last name, allowing for
   // the fact that a space may already be there
   mName = String::Concat(  " ", mName->Trim() );
   lName = String::Concat(  " ", lName->Trim() );
   
   // this line simply concatenates the two strings
   Console::WriteLine( "Welcome to this page, '{0}'!", String::Concat( String::Concat( fName, mName ), lName ) );
}
// The example displays the following output:
//        Welcome to this page, 'Simon Jake Harrows'!
using System;

public class ConcatTest {
    public static void Main() {

        // we want to simply quickly add this person's name together
        string fName = "Simon";
        string mName = "Jake";
        string lName = "Harrows";

        // because we want a name to appear with a space in between each name, 
        // put a space on the front of the middle, and last name, allowing for
        // the fact that a space may already be there
        mName = " " + mName.Trim();
        lName = " " + lName.Trim();

        // this line simply concatenates the two strings
        Console.WriteLine("Welcome to this page, '{0}'!", string.Concat( string.Concat(fName, mName), lName ) );
    }
}
// The example displays the following output:
//        Welcome to this page, 'Simon Jake Harrows'!
Public Class ConcatTest
    Public Shared Sub Main()
        Dim fName As String = "Simon"
        Dim mName As String = "Jake"
        Dim lName As String = "Harrows"
        
        ' We want to simply quickly add this person's name together.
        ' Because we want a name to appear with a space in between each name, 
        ' we put a space on the front of the middle, and last name, allowing for
        ' the fact that a space may already be there.
        mName = " " + mName.Trim()
        lName = " " + lName.Trim()
        
        ' This line simply concatenates the two strings.
        Console.WriteLine("Welcome to this page, '{0}'!", _
                          String.Concat(String.Concat(fName, mName), lName))
    End Sub
End Class
' The example displays the following output:
'       Welcome to this page, 'Simon Jake Harrows'!

注解

方法连接str0str1; 它不添加任何分隔符。The method concatenates str0 and str1; it does not add any delimiters.

Empty字符串用于替代任何空参数。An Empty string is used in place of any null argument.

另请参阅

Concat<T>(IEnumerable<T>) Concat<T>(IEnumerable<T>) Concat<T>(IEnumerable<T>) Concat<T>(IEnumerable<T>)

串联 IEnumerable<T> 实现的成员。Concatenates the members of an IEnumerable<T> implementation.

public:
generic <typename T>
 static System::String ^ Concat(System::Collections::Generic::IEnumerable<T> ^ values);
[System.Runtime.InteropServices.ComVisible(false)]
public static string Concat<T> (System.Collections.Generic.IEnumerable<T> values);
static member Concat : seq<'T> -> string
Public Shared Function Concat(Of T) (values As IEnumerable(Of T)) As String

类型参数

T

values 成员的类型。The type of the members of values.

参数

values
IEnumerable<T> IEnumerable<T> IEnumerable<T> IEnumerable<T>

一个实现 IEnumerable<T> 接口的集合对象。A collection object that implements the IEnumerable<T> interface.

返回

values 中的串联成员。The concatenated members in values.

异常

示例

下面的示例定义了一个非常Animal简单的类, 其中包含动物的名称及其所属的顺序。The following example defines a very simple Animal class that contains the name of an animal and the order to which it belongs. 然后, 它定义List<T>一个对象, 该对象包含Animal多个对象。It then defines a List<T> object to contain a number of Animal objects. 调用扩展方法以提取其Order属性等于Animal "啮齿类" 的对象。 Enumerable.WhereThe Enumerable.Where extension method is called to extract the Animal objects whose Order property equals "Rodent". 结果传递Concat<T>(IEnumerable<T>)给方法并显示到控制台。The result is passed to the Concat<T>(IEnumerable<T>) method and displayed to the console.

using System;
using System.Collections.Generic;
using System.Linq;

public class Animal
{
   public string Kind;
   public string Order;
   
   public Animal(string kind, string order)
   {
      this.Kind = kind;
      this.Order = order;
   }
   
   public override string ToString()
   {
      return this.Kind;
   }
}

public class Example
{
   public static void Main()
   {
      List<Animal> animals = new List<Animal>();
      animals.Add(new Animal("Squirrel", "Rodent"));
      animals.Add(new Animal("Gray Wolf", "Carnivora"));
      animals.Add(new Animal("Capybara", "Rodent"));
      string output = String.Concat(animals.Where( animal => 
                      (animal.Order == "Rodent")));
      Console.WriteLine(output);  
   }
}
// The example displays the following output:
//      SquirrelCapybara
Imports System.Collections.Generic

Public Class Animal
   Public Kind As String
   Public Order As String
   
   Public Sub New(kind As String, order As String)
      Me.Kind = kind
      Me.Order = order
   End Sub
   
   Public Overrides Function ToString() As String
      Return Me.Kind
   End Function
End Class

Module Example
   Public Sub Main()
      Dim animals As New List(Of Animal)
      animals.Add(New Animal("Squirrel", "Rodent"))
      animals.Add(New Animal("Gray Wolf", "Carnivora"))
      animals.Add(New Animal("Capybara", "Rodent")) 
      Dim output As String = String.Concat(animals.Where(Function(animal) _
                                           animal.Order = "Rodent"))
      Console.WriteLine(output)                                           
   End Sub
End Module
' The example displays the following output:
'      SquirrelCapybara

注解

此方法连接中values的每个对象; 它不添加任何分隔符。The method concatenates each object in values; it does not add any delimiters.

Empty字符串用于替代任何空参数。An Empty string is used in place of any null argument.

Concat<T>(IEnumerable<T>)是一种简便方法, 使您可以连接IEnumerable<T>集合中的每个元素, 而无需先将元素转换为字符串。Concat<T>(IEnumerable<T>) is a convenience method that lets you concatenate each element in an IEnumerable<T> collection without first converting the elements to strings. 此方法对语言集成查询 (LINQ) 查询表达式特别有用, 如示例中所示。It is particularly useful with Language-Integrated Query (LINQ) query expressions, as the example illustrates. IEnumerable<T>集合中每个对象的字符串表示形式都是通过调用该对象的ToString方法派生的。The string representation of each object in the IEnumerable<T> collection is derived by calling that object's ToString method.

适用于