c# - 什么是 String.CopyTo？

Question

谁能解释为什么这段代码的输出只是“hello”以及这段代码的含义？

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

输出显示:

The character array is: hello

The code follows:

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

这是因为你的数组只设置了 5 个字符。将其扩展到 11 即可。

Copyto 是这样的:

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

ParameterssourceIndexType: System..::.Int32A character position in this instance. destinationType: array[]()[]An array of Unicode characters. destinationIndexType: System..::.Int32An array element in destination. countType: System..::.Int32The number of characters in this instance to copy to destination. 

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