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，今天看到上有人问如何传Struct。下面是我的解决方法。
[StructLayout(LayoutKind.Sequential)]
public
struct
COPYDATASTRUCT
{ public int dwData; public int cbData; public int lpData; }
[DllImport(
"
user32
"
, EntryPoint
=
"
SendMessageA
"
)]
public
static
extern
int
SendMessage(
int
Hwnd,
int
wMsg,
int
wParam,
ref
COPYDATASTRUCT lParam);
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)] public string cPath; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 10)] public string lPath; public bool status; }
//
发送方代码
WholeInfo h
=
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
GCHandle GC
=
GCHandle.Alloc(Bytes, GCHandleType.Pinned); IntPtr ptr1
=
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.Message m)
{ switch(m.Msg) { case WM_COPYDATA: COPYDATASTRUCT RecvData = (COPYDATASTRUCT)m.GetLParam(typeof(COPYDATASTRUCT)); WholeInfo h = (WholeInfo)Marshal.PtrToStructure((IntPtr)RecvData.lpData, typeof(WholeInfo)); this.textBox1.Text = h.cPath ; break; default: base.DefWndProc(ref m); 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
