C#中结构体与字节流互相转换

因为程序必须要和C++开发的程序通信，而通信数据的是结构体的转化后的字节流，那么就要求C#能够顺利的将字节流转换为C#结构体。

 

1. 定义与C++对应的C#结构体
   

    

   //C++结构体
   struct tagCheakUser        
   {
   char userName[12];
   char pwd[32];
   }
   
   
   
   //对应的C#结构体
   [StructLayout( LayoutKind.Sequential,Pack=1)]
   public struct CheckUser
   {
       [MarshalAs( UnmanagedType.ByValTStr,SizeConst=12)]
   public string userName;
       [MarshalAs(UnmanagedType .ByValTStr,SizeConst=32)]
   public string pwd;
   }
   

    

   
   在C++的头文件定义中，使用了 #pragma pack 1 字节按1对齐，所以C#的结构体也必须要加上对应的特性，LayoutKind.Sequential属性让结构体在导出到非托管内存时按出现的顺序依次布局,而对于C++的char数组类型，C#中可以直接使用string来对应，当然了，也要加上封送的特性和长度限制。
2. 结构体与byte[]的互相转换
   

    

   //convert structure T to byte[] 
   public static byte[] ConvertStructToBytes(object objStruct)
   {
   //get the size of structure
   int size = Marshal.SizeOf(objStruct);
   //define buffer arrays
   byte[] buffer = new byte[size];
   //Alloc unmanaged memory and Copy structure to unmanaged memory
       IntPtr ipStruct = Marshal.AllocHGlobal(size);
       Marshal.StructureToPtr(objStruct, ipStruct, false);
   //Copy to the byte array
       Marshal.Copy(ipStruct, buffer, 0, size);
   //Free unmanaged  memory
       Marshal.FreeHGlobal(ipStruct);
   return buffer;
   }
   
   //convert byte array to sturcture
   public static TR ConvertBytesToSturct<TR>(byte[] datas)
   {
   //get size of sturcture
   int size = Marshal.SizeOf(typeof(TR));
   //can not be convert
   if (datas.Length < size)
       {
   return default(TR);
       }
   //Alloc unmanaged memory and copy bytes data to memory
       IntPtr ipSturct = Marshal.AllocHGlobal(size);
       Marshal.Copy(datas, 0, ipSturct, size);
   //Convert IntPtr to structure
       TR objStruct = (TR)Marshal.PtrToStructure(ipSturct, typeof(TR));
   //Free unmanaged memory
       Marshal.FreeHGlobal(ipSturct);
   return objStruct;
   }
   
   

3. 测试
   
   

    static void Main(string[] args)
    {
        DataAPI.CheckUser ckUser = new DataAPI.CheckUser() { userName = "douzi",pwd="00" };
   byte[] bDatas = Converter.ConvertStructToBytes(ckUser);
        DataAPI.CheckUser ckUser1 = Converter.ConvertBytesToSturct<DataAPI.CheckUser>(bDatas);
        Console.WriteLine("User:{0} Pwd:{1}", ckUser1.userName, ckUser1.pwd);
        Console.ReadKey();
    }
   

    

   
   

 

这样，就能有效的和C++通讯了。