using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Runtime.InteropServices;
namespace FileSendClient
{
 
  [StructLayoutAttribute(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)]
  struct StructDemo
  {
    
    public byte a;
    public byte c;
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
    public byte[] b;
    public byte d;
    public int e;
    
  }
  unsafe class Program
  {
    static void Main(string[] args)
    {
      StructDemo sd;
      sd.a = 0;
      sd.d = 0;
      sd.c = 0;
      sd.b = new byte[3] { 0, 0, 1 };
      sd.e = 5;
      int size = 0;
      //此處使用非安全代碼來獲取到StructDemo的值
      unsafe
      {
        size = Marshal.SizeOf(sd);
      }
       
      byte[] b = StructToBytes(sd,size);
 
      ByteToStruct(b, typeof(StructDemo));
 
    }
 
 
    //將Byte轉換為結構體類型
    public static byte[] StructToBytes(object structObj,int size)
    {
      StructDemo sd;
      int num = 2;
      byte[] bytes = new byte[size];
      IntPtr structPtr = Marshal.AllocHGlobal(size);
      //將結構體拷到分配好的內(nèi)存空間
      Marshal.StructureToPtr(structObj, structPtr, false);
      //從內(nèi)存空間拷貝到byte 數(shù)組
      Marshal.Copy(structPtr, bytes, 0, size);
      //釋放內(nèi)存空間
      Marshal.FreeHGlobal(structPtr);
      return bytes;
 
    }
 
    //將Byte轉換為結構體類型
    public static object ByteToStruct(byte[] bytes, Type type)
    {
      int size = Marshal.SizeOf(type);
      if (size > bytes.Length)
      {
        return null;
      }
      //分配結構體內(nèi)存空間
      IntPtr structPtr = Marshal.AllocHGlobal(size);
      //將byte數(shù)組拷貝到分配好的內(nèi)存空間
      Marshal.Copy(bytes, 0, structPtr, size);
      //將內(nèi)存空間轉換為目標結構體
      object obj = Marshal.PtrToStructure(structPtr, type);
      //釋放內(nèi)存空間
      Marshal.FreeHGlobal(structPtr);
      return obj;
    }
  }
}