C#接收SendMessage的一些方案

关于如何使用SendMessage方法发送文字

接收侧窗口类可以这么写（C#）

namespace MessageHandler
{
    [StructLayout(LayoutKind.Sequential)]
    public struct COPYDATASTRUCT
    {
        public IntPtr dwData;
        public int cbData;

        [MarshalAs(UnmanagedType.LPTStr)] //这里用LPStr会报错
        public string lpData;
    }

    public partial class MessageForm : Form
    {
        protected override void DefWndProc(ref Message m)
        {
            base.DefWndProc(ref m);
            if (m.Msg != 74) return;

            var lParam = m.LParam;
            var data = Marshal.PtrToStructure<COPYDATASTRUCT>(lParam);
            Console.WriteLine(data.lpData);
            if (data.lpData == null) return;
            var s = data.lpData.Substring(0, data.cbData / 2); //不切割尾部会多东西
            Console.WriteLine(s);//业务代码
        }

        public MessageForm()
        {
            InitializeComponent();
            Console.WriteLine(this.Handle);
        }
    }