using System;
using System.Runtime.InteropServices;

namespace SendMsgToWindow
{
    class MainClass
    {
        //[DllImport("USER32.DLL")]
        [DllImport("user32.dll", EntryPoint = "FindWindow")]
        public static extern IntPtr FindWindow (string lpClassName, string lpWindowName);
    
        //静态方法必须在静态方法中调用？
        private static void MyFindWindow (string wndName)
        {
            IntPtr ip = FindWindow (null, wndName);
            Console.WriteLine(ip.ToString());
            if (ip != IntPtr.Zero) {
                //找到句柄后,你就可以做你想做的事了,发送信息你可以用SendKeys;
                Console.WriteLine ("yes");
            }
        }

        public static void Main (string[] args)
        {
            MyFindWindow ("test.txt - 记事本");//
        }
    }
}