.net 调用 winapi获取窗口句柄和内容

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

namespace cstest
{
    public partial class Form1 : Form
    {
        //定义一个符合WINAPI返回值和参数的委托
        public delegate bool CallBack(IntPtr hwnd, int lParam);
        //声明符合上述委托的函数（定义一个函数指针）
        private static CallBack myCallBack;
        public Form1()
        {
            myCallBack = new CallBack(Report);
        InitializeComponent();
            GetHandle("C#");
            this.textBox1.Multiline = true;
            this.textBox1.Dock = DockStyle.Fill;
        }

        private void GetHandle(string windcaption)
        {
            IntPtr mainHandle = FindWindow(null, windcaption);
            if (IntPtr.Zero != mainHandle)
            {
                AppendText(string.Format("{0}句柄：{1}", windcaption, Convert.ToString((int)mainHandle,)));

                //EnumChildWindows((int)mainHandle, myCallBack, 0);
                //修改窗口标题
                SetWindowText((int)mainHandle, "C#");
                StringBuilder s = new StringBuilder();
                //获取控件标题
                int i = GetWindowText(mainHandle, s, s.Capacity);
                AppendText(string.Format("句柄{0}的caption：{1}", Convert.ToString((int)mainHandle, ), s.ToString()));
                //枚举所有子窗体，并将子窗体句柄传给myCallBack
                EnumChildWindows((int)mainHandle, myCallBack, );
            }
        }

        private void AppendText(string msg)
        {
            this.textBox1.AppendText(msg);
            this.textBox1.AppendText("\r\n");
        }
        //根据窗体句柄，输出窗体caption
        public bool Report(IntPtr hWnd, int lParam)
        {
            StringBuilder s = new StringBuilder();
            int i = GetWindowText((IntPtr)hWnd, s, s.Capacity);
            AppendText(string.Format("句柄{0}的caption：{1}", Convert.ToString((int)hWnd, ), s.ToString()));
            return true;
        }

        /// <summary>
        /// 获取窗体的句柄函数
        /// </summary>
        /// <param name="lpClassName">窗口类名</param>
        /// <param name="lpWindowName">窗口标题名</param>
        /// <returns>返回句柄</returns>
        [DllImport("user32.dll", EntryPoint = "FindWindow", SetLastError = true)]
        public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

        [DllImport("user32.dll")]
        public static extern int EnumWindows(CallBack x, int y);

        [DllImport("user32.dll")]
        private static extern IntPtr EnumChildWindows(int hWndParent, CallBack lpEnumFunc, int lParam);

        [DllImport("user32.dll")]
        public static extern int SetWindowText(int handle, string title);

        [DllImport("user32.dll", EntryPoint = "GetWindowText")]
        public static extern int GetWindowText(IntPtr hwnd, StringBuilder lpString,int cch);

        [DllImport("User32.dll", EntryPoint = "SendMessage")]
        private static extern int SendMessage(IntPtr hWnd, int Msg, int wParam, StringBuilder lParam);

        private void button1_Click(object sender, EventArgs e)
        {
            StringBuilder s = new StringBuilder();
            //获取控件标题,对TRichEdit无效
            //int i = GetWindowText((IntPtr)int.Parse(txtHandle.Text), s, s.Capacity);
            //获取控件标题,对TRichEdit有效
            int i = SendMessage((IntPtr)int.Parse(txtHandle.Text), 0x000D, , s);
            AppendText(string.Format("句柄{0}的caption：{1}", txtHandle.Text, s.ToString()));
        }
    }
}