byte[]数组的赋值问题！急！！！

[eyoexply]

有一个byte[] a=new byte[128]
我想把从a[0]开始赋值为abc
从a[20]开始赋值为abcded
从a[60]开始赋值为afdfie
类似这样的赋值要怎么做？

[saucer]

as you long as you have enough space

byte[] bs = System.Text.Encoding.ASCII.GetBytes("abc");
Array.Copy(bs,0,a,0, bs.Length);

bs = System.Text.Encoding.ASCII.GetBytes("abcdef");
Array.Copy(bs,0,a,20, bs.Length);

bs = System.Text.Encoding.ASCII.GetBytes("afdfie");
Array.Copy(bs,0,a,60, bs.Length);