WinForm跨进程通信

public class WinMessageHelper
{
    private struct COPYDATASTRUCT
    {
        public IntPtr dwData;
        public int cbData;
        [MarshalAs(UnmanagedType.LPStr)]
        public string lpData;
    }

    //使用COPYDATA进行跨进程通信
    public const int WM_COPYDATA = 0x004A;

    [DllImport("User32.dll", EntryPoint = "SendMessage")]
    private static extern int SendMessage(
    int hWnd, // handle to destination window
    int Msg, // message
    int wParam, // first message parameter
    ref COPYDATASTRUCT lParam // second message parameter
    );

    [DllImport("User32.dll", EntryPoint = "FindWindow")]
    private static extern int FindWindow(string lpClassName, string lpWindowName);

    /// <summary>
    /// 发送消息
    /// </summary>
    /// <param name="windowReceiveTitle">接收方窗体标题名称</param>
    /// <param name="strData">要发送的数据</param>
    public static void Send(string windowReceiveTitle, string strData)
    {
        int winHandler = FindWindow(null,windowReceiveTitle);
        if (winHandler != 0)
        {
            byte[] sarr = System.Text.Encoding.Default.GetBytes(strData);
            int len = sarr.Length + 1;
            COPYDATASTRUCT cds;
            cds.dwData = (IntPtr)100;
            cds.lpData = strData;
            cds.cbData = len;
            SendMessage(winHandler, WM_COPYDATA, 0, ref cds);
        }
    }

    /// <summary>
    /// 接收消息
    /// </summary>
    /// <example>
    /// 在窗体中覆盖接收消息函数
    /// protected override void DefWndProc(ref System.Windows.Forms.Message m)
    /// {
    ///     switch(m.Msg)
    ///     {
    ///         case WinMessageHelper.WM_COPYDATA:
    ///             string str = WinMessageHelper.Receive(ref m);
    ///             break;
    ///         default:
    ///             base.DefWndProc(ref m);
    ///             break;
    /// 
    ///     }
    /// }
    /// </example>
    /// <returns>接收的到数据</returns>
    public static string Receive(ref System.Windows.Forms.Message m)
    {
        COPYDATASTRUCT cds = new COPYDATASTRUCT();
        Type cdsType = cds.GetType();
        cds = (COPYDATASTRUCT)m.GetLParam(cdsType);
        return cds.lpData;
    }

}