用WM_COPYDATA传递struct

利用WM_COPYDATA可以轻松实现两个进程间的通信，但是一般都是传string数据，今天看到优快云上有人问如何传Struct。下面是我的解决方法。

[StructLayout(LayoutKind.Sequential)]
public struct COPYDATASTRUCT
{
publicintdwData;
publicintcbData;
publicintlpData;
}
[DllImport( " user32 " ,EntryPoint = " SendMessageA " )]
public static extern int SendMessage( int Hwnd, int wMsg, int wParam, ref COPYDATASTRUCTlParam);
const int WM_COPYDATA = 0x004A ;

// 定义要传递的Struct
[StructLayout(LayoutKind.Sequential)]
struct WholeInfo
{
//SizeConst指定字符串很重要，后面要用到
[MarshalAs(UnmanagedType.ByValTStr,SizeConst=10)]
publicstringcPath;
[MarshalAs(UnmanagedType.ByValTStr,SizeConst=10)]
publicstringlPath;
publicboolstatus;
}


// 发送方代码

WholeInfoh = new WholeInfo();
h.lPath = " lPath " ;
h.cPath = " cPath " ;
h.status = true ;
int size = Marshal.SizeOf( typeof (WholeInfo));
byte []Bytes = new byte [size];
// 根据定义的尺寸分配内存块
GCHandleGC = GCHandle.Alloc(Bytes,GCHandleType.Pinned);
IntPtrptr1 = GC.AddrOfPinnedObject();
// 获得Struct对应的IntPtr
Marshal.StructureToPtr(h,ptr1, false );
SendData.lpData = ptr1.ToInt32();
SendData.cbData = size;

int intHWnd = FindWindow( null , @" 接收方 " );
if (intHWnd > 0 )
{
SendMessage(intHWnd,WM_COPYDATA,0,ref(SendData));
}

// 接收方代码

// 处理消息
protected override void DefWndProc( ref System.Windows.Forms.Messagem)
{
switch(m.Msg)
{
caseWM_COPYDATA:
COPYDATASTRUCTRecvData=(COPYDATASTRUCT)m.GetLParam(typeof(COPYDATASTRUCT));
WholeInfoh=(WholeInfo)Marshal.PtrToStructure((IntPtr)RecvData.lpData,typeof(WholeInfo));
this.textBox1.Text=h.cPath;

break;
default:
base.DefWndProc(refm);
break;

}

}

关键的代码就是
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 10)]

这样C#才能分配正确的内存位置，但是要记住一个汉字占2位