C# 软件之间通讯之WM_COPYDATA

using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Runtime.InteropServices; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; namespace testmessage { public partial class Form1 : Form { const int WM_COPYDATA = 0x004A; public struct COPYDATASTRUCT { public IntPtr dwData; public int cData; [MarshalAs(UnmanagedType.LPStr)] public string lpData; } [DllImport("User32.dll")] public static extern int SendMessage(int hwnd, int msg, int wParam, ref COPYDATASTRUCT lParam); [DllImport("User32.dll")] public static extern int FindWindow(string lpClassName, string lpWindowName); public Form1() { InitializeComponent(); } public bool sendmessageto(string windowname, string data) { int WINDOW_HANDLE = FindWindow(null, windowname); if (WINDOW_HANDLE != 0) { byte[] arr = System.Text.Encoding.Default.GetBytes(data); int len = arr.Length; COPYDATASTRUCT cdata; cdata.dwData = (IntPtr)100; cdata.lpData = data; cdata.cData = len + 1; SendMessage(WINDOW_HANDLE, WM_COPYDATA, 0, ref cdata); return true; } else return false; } protected override void DefWndProc(ref Message m) { switch (m.Msg) { case WM_COPYDATA: COPYDATASTRUCT cdata = new COPYDATASTRUCT(); Type mytype = cdata.GetType(); cdata = (COPYDATASTRUCT)m.GetLParam(mytype); this.label1.Text = cdata.lpData; break; default: base.DefWndProc(ref m); break; } } private void send_Click(object sender, EventArgs e) { sendmessageto(this.Windowname.Text, this.Message.Text); } } }