1.  // Program.cs

2.  using System;

3.  using System.Collections.Generic;

4.  using System.ComponentModel;

5.  using System.Data;

6.  using System.Drawing;

7.  using System.Linq;

8.  using System.Text;

9.  using System.Windows.Forms;

10.using System.Diagnostics;

11.using System.Runtime.InteropServices;

12.

13.namespace WindowsFormsApplication4

14.{

15.    public partial class Form1 : Form

16.    {

17.        public Form1()

18.        {

19.            InitializeComponent();

20.        }

21.

22.        //查找窗口API

23.        [DllImport("user32.dll", EntryPoint = "FindWindow")]

24.        public extern static IntPtr FindWindow(string lpClassName, string lpWindowName);

25.

26.        //查找窗口内控件句柄

27.        [DllImport("user32.dll", EntryPoint = "FindWindowEx", SetLastError = true)]

28.        public static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);

29.

30.        //发送消息

31.

32.        [DllImport("user32.dll", EntryPoint = "SendMessageA")]

33.        private static extern int SendMessage(IntPtr hwnd, int wMsg, int wParam, StringBuilder lParam);

34.

35.        private void button1_Click(object sender, EventArgs e)

36.        {

37.            IntPtr mW = FindWindow(null, "MyForm");

38.            if (mW != IntPtr.Zero)

39.            {

40.                MessageBox.Show("找到程序窗口！");

41.                IntPtr et = FindWindowEx(mW, IntPtr.Zero, "WindowsForms10.EDIT.app.0.2bf8098_r16_ad1", null); //第三个参数使用spy++找的，不要告诉我不知道呀

42.                if (et != IntPtr.Zero) {

43.                    MessageBox.Show("找到文本框！");

44.

45.

46.                    StringBuilder s1 = new StringBuilder(512);

47.                    SendMessage(et, 0x000d, 510, s1); //0x000d是向控件发送获取文本消息的消息编号

48.                    MessageBox.Show(s1.ToString());

49.                } else {

50.                    MessageBox.Show("没找到文本框！");

51.                }

52.            }

53.            else {

54.                MessageBox.Show("没有窗口！");

55.            }

56.        }

57.    }

58.}