c# 模拟第三方程序按钮的单击

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace 模拟三方程序窗口的按钮
{

    public partial class Form1 : Form
    {
        [DllImport("User32.dll", EntryPoint = "FindWindow")]
        public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

        [DllImport("User32.dll", EntryPoint = "FindWindowEx")]
        public static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpClassName, string lpWindowName);

        [DllImport("User32.Dll", EntryPoint = "PostMessageA")]
        public static extern bool PostMessage(IntPtr hWnd, uint msg, int wParam, int lParam);

        [DllImport("user32.dll", EntryPoint = "SendMessage", SetLastError = true, CharSet = CharSet.Auto)]
        private static extern int SendMessage(IntPtr hwnd, uint wMsg, int wParam, int lParam);                  

        const uint BM_CLICK = 0xF5;

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            IntPtr ParenthWnd = new IntPtr(0);
            ParenthWnd = FindWindow(null, "aaa");
            IntPtr btnPtr = FindWindowEx(ParenthWnd, IntPtr.Zero, null, "开");
            SendMessage(btnPtr, BM_CLICK, 0, 0);
            
        }

        private void button2_Click(object sender, EventArgs e)
        {
            IntPtr ParenthWnd = new IntPtr(0);
            ParenthWnd = FindWindow(null, "aaa");   
            IntPtr btnPtr = FindWindowEx(ParenthWnd, IntPtr.Zero, null, "关");  
            PostMessage(btnPtr,  BM_CLICK, 0, 0);
            
        }
    }
}