Question

C# 中如何填充数组

byte[] ar = new byte[1024];

申明了这一个数组，我想用0xff填充这个这个数组该怎么写？
c++中有memset(), delphi中有fillchar().

Answer 1

好像没有你说的那种写法，只能循环赋值，获知使用 SetValue 方法

SetValue 方法
public void SetValue (
Object value,
int index
)

参数
value
指定元素的新值。

index
一个 32 位整数，它表示要设置的 Array 元素的位置。

示例：
下面的代码示例阐释了如何设置和获取一维或多维数组中的特定值。
using System;

public class SamplesArray {

public static void Main() {

// Creates and initializes a one-dimensional array.
String[] myArr1 = new String[5];

// Sets the element at index 3.
myArr1.SetValue( "three", 3 );
Console.WriteLine( "[3]: {0}", myArr1.GetValue( 3 ) );

// Creates and initializes a two-dimensional array.
String[,] myArr2 = new String[5,5];

// Sets the element at index 1,3.
myArr2.SetValue( "one-three", 1, 3 );
Console.WriteLine( "[1,3]: {0}", myArr2.GetValue( 1, 3 ) );

// Creates and initializes a three-dimensional array.
String[,,] myArr3 = new String[5,5,5];

// Sets the element at index 1,2,3.
myArr3.SetValue( "one-two-three", 1, 2, 3 );
Console.WriteLine( "[1,2,3]: {0}", myArr3.GetValue( 1, 2, 3 ) );

// Creates and initializes a seven-dimensional array.
String[,,,,,,] myArr7 = new String[5,5,5,5,5,5,5];

// Sets the element at index 1,2,3,0,1,2,3.
int[] myIndices = new int[7] { 1, 2, 3, 0, 1, 2, 3 };
myArr7.SetValue( "one-two-three-zero-one-two-three", myIndices );
Console.WriteLine( "[1,2,3,0,1,2,3]: {0}", myArr7.GetValue( myIndices ) );

}

}

/*
This code produces the following output.

[3]: three
[1,3]: one-three
[1,2,3]: one-two-three
[1,2,3,0,1,2,3]: one-two-three-zero-one-two-three

*/

Answer 2

byte[] ar = new byte[1024];
for (int i = 0; i < 1024; i++)
{
ar[i] = 0xff;
}