C# 窗口程序间发送数据

两个窗口之间发送数据

        // 进程间发送数据
        [DllImport("User32.dll")]
        public static extern int SendMessage(IntPtr hwnd, int msg, int wParam, ref COPYDATASTRUCT lParam);
        
       // 找到窗口
        [DllImport("user32.dll", EntryPoint = "FindWindow", SetLastError = true)]
        private static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

        // 发送消息的类型
        const int WM_COPYDATA = 0x004A;
        
       // 用作数据传递的结构体
        public struct COPYDATASTRUCT
        {
            public IntPtr dwData;
            public int cbData;
            public IntPtr lpData;
        }

				// 发送数据
				private void SendToAnotherProcess(byte[] data)
        {
            // 向另一个进程窗口发送
            IntPtr hwnd = FindWindow(null, "窗口名称");
            if (hwnd != IntPtr.Zero)
            {
                COPYDATASTRUCT cds;
                cds.dwData = IntPtr.Zero;                                       //可以是任意值
                cds.cbData = data.Length;                                      //指定lpData内存区域的字节数
                cds.lpData = Marshal.AllocHGlobal(data.Length);
                Marshal.Copy(data, 0, cds.lpData, data.Length);    // 将字节数组复制到 COPYDATASTRUCT 结构体中
                SendMessage(hwnd, WM_COPYDATA, 0, ref cds);       
            }
        }

				// 接收数据
				protected override void DefWndProc(ref System.Windows.Forms.Message m)
        {
            switch (m.Msg)
            {
                case WM_COPYDATA:
                    InvByScannCode(ref m);
                    break;
                default:
                    base.DefWndProc(ref m);//调用基类函数处理非自定义消息。
                    break;
            }
        }

        private void InvByScannCode(ref System.Windows.Forms.Message m)
        {
            COPYDATASTRUCT cdata = new COPYDATASTRUCT();
            Type mytype = cdata.GetType();
            cdata = (COPYDATASTRUCT)m.GetLParam(mytype);
            byte[] data = new byte[cdata.cbData];   // 复制字节数组数据
            Marshal.Copy(cdata.lpData, data, 0, data.Length);
            Console.WriteLine("接收数据{0}", BytesToHexString(data, 0, data.Length));
            Receive(data);
        }

        //byte[]转16进制string
        //0x13 0xab 0xef   ->   “13ABEF”
        public static string BytesToHexString(byte[] bytes, int offset, int length)
        {
            string hexString = string.Empty;
            if ((bytes != null) && (length != 0))
            {
                StringBuilder strB = new StringBuilder();
                for (int i = offset; i < length + offset; i++)
                {
                    strB.Append(bytes[i].ToString("X2"));
                }
                hexString = strB.ToString();
            }
            return hexString;
        }