什么是String.CopyTo？

Question

任何人都可以解释为什么这段代码的输出只是'你好'以及这段代码的含义是什么？

( 0, characterArray, 0, characterArray.Length );

输出显示:

字符数组是:hello

代码如下:

string string1 = "hello there";
char[] characterArray = new char[ 5 ];

string1.CopyTo( 0, characterArray, 0, characterArray.Length );
Console.Write( "\nThe character array is: " );

for ( int i = 0; i < characterArray.Length; i++ )
    Console.Write( characterArray[ i ] );

Answer 1

这是因为您的数组仅设置为5个字符.将它扩展为11,它将工作.

以下是Copyto的内容:

public void CopyTo(
    int sourceIndex,
    char[] destination,
    int destinationIndex,
    int count
)

Parameters
sourceIndex
Type: System..::.Int32
A character position in this instance. 

destination
Type: array[]()[]
An array of Unicode characters. 

destinationIndex
Type: System..::.Int32
An array element in destination. 

count
Type: System..::.Int32
The number of characters in this instance to copy to destination. 

摘自:http://msdn.microsoft.com/en-us/library/system.string.copyto.aspx