C#中[]的几种用法示例代码

[DllImport(“kernel32.dll”)]
private static extern void FunName(arg，[arg]);

using System;
using System.Text;
using System.Runtime.InteropServices;
namespace Windows.Help
{
    public partial class SystemInfo
    {
        [DllImport("kernel32")]
        public static extern void GetWindowsDirectory(StringBuilder WinDir, int count);
        [DllImport("kernel32")]
        public static extern void GetSystemDirectory(StringBuilder SysDir, int count);
        public static void Main () {
            const int nChars = 128;
            StringBuilder Buff = new StringBuilder(nChars);
            GetWindowsDirectory(Buff, nChars);
            String t = "Windows路径：" + Buff.ToString();
            System.Console.WriteLine(t);
        }
    }
}

struct S1{
  int a;
  int b;
}

[StructLayout(LayoutKind.Sequential)] 
struct S1
{
  int a;
  int b;
}

[StructLayout(LayoutKind.Explicit)] 
struct S1
{
  [FieldOffset(0)]
  int a;
  [FieldOffset(0)]
  int b;
}