c# copydata 消息

using PublicCode;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace broadcast2
{
    public partial class broadcast2 : Form
    {
        IPAddress IP = null;
        EndPoint SendEP = null;
        Socket sock = null;

        private string logfile = "";
        private int index = ;
        private Thread rcvThread = null;
        public broadcast2()
        {
            InitializeComponent();
            StartPosition = FormStartPosition.CenterScreen;

            sock = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
            sock.EnableBroadcast = true;

            textBox2.Text = this.Handle.ToString();
            logfile = Path.Combine(Application.StartupPath, "logs.txt");

            this.Text = "发送者";
        }
        protected override void WndProc(ref Message m)
        {
            base.WndProc(ref m);

            if (m.Msg == 0x04A)
            {
                COPYDATASTRUCT cdata = new COPYDATASTRUCT();
                Type mytype = cdata.GetType();
                cdata = (COPYDATASTRUCT)m.GetLParam(mytype);
                MessageBox.Show(cdata.lpData);
            }

            if (m.Msg == 1025)
            {
                string text = "";
                PublicUtils.GlobalGetAtomName(m.LParam.ToInt32(), text, 1024);

                MessageBox.Show(text);
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            //PublicUtils.SendFormMsg_Copydata(PublicUtils.FindWindow("TForm2", "Form2"), "xxx 暗室逢灯12345  54321");

            PublicUtils.SendFormMsg(PublicUtils.FindWindow("TForm2", "Form2"), "xxx 暗室逢灯12345  54321--");
        }

        private void Send()
        {
            //byte[] sendbuf = Encoding.UTF8.GetBytes(string.Format("消息 {0}",  ++index));
            byte[] sendbuf = Encoding.UTF8.GetBytes(DateTime.Now.ToString("HHmmss"));
            sock.SendTo(sendbuf, SendEP);
            //Console.WriteLine(string.Format("{0} 发送广播消息 {1}", DateTime.Now.ToString("HH:mm:ss.fff"), i));
            writeLog(string.Format("{0} 发送广播消息 {1}", DateTime.Now.ToString("HH:mm:ss.fff"), DateTime.Now.ToString("HHmmss")));

            //byte[] receiveBuf = new byte[1000];
            //sock.Receive(receiveBuf);
            //string msg = Encoding.UTF8.GetString(receiveBuf, 0, receiveBuf.Length);
            ////Console.WriteLine(string.Format("{0} 收到回复： {0}", DateTime.Now.ToString("HH:mm:ss.fff"), msg);
            //writeLog(string.Format("{0} 收到回复： {1}", DateTime.Now.ToString("HH:mm:ss.fff"), msg));

        }

        private void writeLog(string text)
        {
            using (StreamWriter sw = new StreamWriter(logfile, true, Encoding.UTF8))
            {
                sw.WriteLine(text);
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            index = ;
            if (!timer1.Enabled)
            {
                IP = IPAddress.Parse(textBox1.Text.Trim());
                SendEP = new IPEndPoint(IP, );

                timer1.Start();
                button1.Text = "停止";
                textBox1.Enabled = false;

                rcvThread = new Thread(new ThreadStart(DoReceive));
                rcvThread.IsBackground = true;
                rcvThread.Start();
            }
            else
            {
                timer1.Stop();
                button1.Text = "开始";
                textBox1.Enabled = true;

                if (rcvThread != null)
                {
                    rcvThread.Abort();
                    rcvThread = null;
                }
            }
        }

        /// <summary>
        /// 方式一：阻塞接收的方式
        /// </summary>
        private void DoReceive()
        {
            while (true)
            {
                try
                {
                    byte[] receiveBuf = new byte[];
                    sock.Receive(receiveBuf);
                    string msg = Encoding.UTF8.GetString(receiveBuf, , receiveBuf.Length);
                    //Console.WriteLine(string.Format("{0} 收到回复： {0}", DateTime.Now.ToString("HH:mm:ss.fff"), msg);
                    string stext = string.Format("{0} 收到：{1}", DateTime.Now.ToString("HH:mm:ss.fff"), msg).Replace('\0', ' ').Trim();
                    writeLog(stext);
                }
                catch
                {

                }
            }
        }
        /// <summary>
        /// 方式二：监听方式,这种方式不行
        /// </summary>
        private void DoReceive2()
        {
            UdpClient listener = new UdpClient();
            IPEndPoint endPoint = new IPEndPoint(IPAddress.Any, );
            listener.ExclusiveAddressUse = false;
            listener.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
            listener.Client.Bind(endPoint);
            while (true)
            {
                byte[] receiveBuf = listener.Receive(ref endPoint);
                string msg = Encoding.UTF8.GetString(receiveBuf, , receiveBuf.Length);
                string stext = string.Format("{0}收到：{1}", DateTime.Now.ToString("HH:mm:ss.fff"), msg).Replace('\0', ' ').Trim();
                writeLog(stext);
            }
        }

        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            timer1.Stop();
            Application.Exit();
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            Send();
        }
        public static void UdpServer(IPEndPoint serverIP)
        {
            bool thread_flag = true;
            Console.WriteLine("UDP服务器开始监听" + serverIP.Port + "端口");
            Socket udpServer = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
            udpServer.Bind(serverIP);
            IPEndPoint ipep = new IPEndPoint(IPAddress.Any, );
            EndPoint Remote = (EndPoint)ipep;
            new Thread(() =>
            {
                while (thread_flag)
                {
                    byte[] data = new byte[];
                    int length = ;
                    try
                    {
                        length = udpServer.ReceiveFrom(data, ref Remote);//接受来自服务器的数据
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(string.Format("出现异常：{0}", ex.Message));
                        break;
                    }
                    string datetime = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
                    string message = Encoding.UTF8.GetString(data, , length);
                    string ipport = (Remote as IPEndPoint).Address.ToString() + ":" + (Remote as IPEndPoint).Port.ToString();
                    Console.WriteLine(string.Format("{0} 收到來自{1}的消息：{2}", datetime, ipport, message));
                }
                udpServer.Close();
            }).Start();
        }
    }
}

公用单元文件：

PublicUtils.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

namespace PublicCode
{
    public static class PublicUtils
    {
        public const int WM_TextNotify = ;

        [DllImport("User32.dll")]
        public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

        [DllImport("user32.dll")]
        public static extern IntPtr SendMessage(IntPtr hwnd, int msg, int wParam, ref COPYDATASTRUCT IParam);
        [DllImport("user32.dll", EntryPoint = "SendMessage")]
        private static extern int SendMessage2(int hwnd, int wMsg, int wParam, int lParam);
        [DllImport("kernel32.dll", CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Unicode)]

        public static extern int GlobalAddAtom(string lpString);

        [DllImport("kernel32.dll", CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Unicode)]
        public static extern int GlobalDeleteAtom(int atom);

        [DllImport("kernel32.dll", CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Unicode)]
        public static extern uint GlobalGetAtomName(int nAtom, string lpBuffer, int nSize);

        public static void SendFormMsg_Copydata(IntPtr handle, string atext)
        {
            byte[] arr = Encoding.Unicode.GetBytes(atext);
            int len = arr.Length;
            COPYDATASTRUCT cdata;
            cdata.dwData = (IntPtr);
            cdata.lpData = atext;
            cdata.cData = len + ;
            SendMessage(handle, 0x04A, , ref cdata);
        }

        public static void SendFormMsg(IntPtr handle, string atext)
        {
            int atom = GlobalAddAtom(atext);
            SendMessage2((int)handle, WM_TextNotify, , atom);
            GlobalDeleteAtom(atom);
        }
    }

    public struct COPYDATASTRUCT
    {
        public IntPtr dwData;
        public int cData;
        [MarshalAs(UnmanagedType.LPWStr)]
        public string lpData;
    }
}

更正：

            IntPtr stext = Marshal.AllocHGlobal(1024);
            if (m.Msg == )
            {
                PublicUtils.GlobalGetAtomName(m.LParam.ToInt32(), stext, );
                textBox3.Text = Marshal.PtrToStringUni(stext);
                Marshal.FreeHGlobal(stext);
            }

        [DllImport("kernel32.dll", CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Unicode)]
        public static extern uint GlobalGetAtomName(int nAtom, IntPtr lpBuffer, int nSize);