SendMessage 发送按键消息不成功
我在第一个From中用SendMessage发送一个消息给第二个From，可是第二个From没有触发这个事件，为什么呢？它没有收到消息么？

第一个窗口的核心代码：

C# code

   public const int wmmsg = 0x0100;   for (int i = 0; i < pros.Length; i++)   {          if (pros[i].MainWindowTitle == "From2")          {            IntPtr hwnd = pros[i].MainWindowHandle;            IntPtr dataint;            SendMessage(hwnd, wmmsg, dataint, (IntPtr)0);          }   }

第二个窗口的：

private void NRCServer_KeyDown(object sender, KeyEventArgs e)
{
RecString = Convert.ToString(e.KeyValue);
label1.Text = RecString;
}

请问是哪一句出了问题？

[解决办法]
c#程序没必要用SendMessage之类的api函数，
[解决办法]

C# code

    private IntPtr _FromHandle = IntPtr.Zero;        public Form1()        {            InitializeComponent();        }        private void button1_Click(object sender, EventArgs e)        {            Form2 frm = new Form2();            frm.Show();            _FromHandle = frm.Handle;        }        private void button2_Click(object sender, EventArgs e)        {            SendMessage(_FromHandle, wmmsg, (IntPtr)3, (IntPtr)1);        }
[解决办法]
C# code
using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Runtime.InteropServices;namespace SendMessageTest{    public partial class Form1 : Form    {        public const int wmmsg = 0x0100;        [DllImport("user32.dll ", EntryPoint = "SendMessage")]        static extern IntPtr SendMessage(IntPtr hWnd, int Msg, int wParam, string lParam);         public Form1()        {            InitializeComponent();        }        Form2 f2;        private void button1_Click(object sender, EventArgs e)        {            f2 = new Form2();            f2.Show();        }        private void button2_Click(object sender, EventArgs e)        {            SendMessage(f2.Handle, wmmsg, 0, "");        }    }}using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;namespace SendMessageTest{    public partial class Form2 : Form    {        public Form2()        {            InitializeComponent();        }        private void Form2_KeyDown(object sender, KeyEventArgs e)        {            MessageBox.Show(e.ToString());        }    }}