怎么将C#通过发消息传递给指定C++窗口

C# 发送方

//引入 Interop 库
using System.Runtime.InteropServices;

//定义 SendMessage API
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = false)]
static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);

//定义发送消息的常量
static uint WM_USER = 0x0400;

//在需要发送消息的位置调用 SendMessage API
SendMessage(hWnd, WM_USER, IntPtr.Zero, IntPtr.Zero);
//如果是字符串
SendMessage(hwnd, WM_USER, Marshal.StringToHGlobalAnsi(""), (IntPtr)0);

C++接收方

//如果是接收字符串
LPCSTR str = reinterpret_cast<LPCSTR>(wParam);
CString cstr = CString(str);
//如果是int类型
int code = wParam

hwnd为C++指定窗口