C# 给指定应用程序发送消息

public partial class FrmMain : Form
{
public FrmMain()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{

try
{
var procecess = Process.GetProcessesByName("SSDS");
if (procecess.Length <= 0)
{
procecess = Process.GetProcessesByName("SSDS.vshost");
}

if (procecess.Length <= 0)
{
MessageBox.Show("请打开程序SSDS");
return;
}

var msgId = Convert.ToInt32(textBox1.Text);

var ssdProcess = procecess[0];
//发消息
PostMessage(ssdProcess.MainWindowHandle, (uint)msgId, IntPtr.Zero, IntPtr.Zero);

//等待退出
ssdProcess.WaitForExit();

//读数据
MessageBox.Show(File.ReadAllText("data.txt"));

}
catch (Exception ex)
{

MessageBox.Show(ex.Message);
}

}
[DllImport("User32.dll")]
static extern IntPtr PostMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);
}