[問題] 請問 這迴圈在哪?

[charles0203 (Mango)]

最近在學API

API的GetWindowText

這程式大概是 根據視窗title 來找到 該視窗介的控件


在表單上 建立一個button 就好了


我不懂的是  究竟是怎樣產生迴圈效果

讓他可以不斷執行 後面這行:
 Console.WriteLine(" Contains text of contro:"+ editText);




程式是用XP的 音量控制 來測試的


程式碼:

using System;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace user32_api_test1
{
    public partial class Form1 : Form
    {

        [DllImport("User32.dll")]
        public static extern Int32 FindWindow(String lpClassName, String
lpWindowName);
        [DllImport("User32.dll")]
        public static extern Boolean EnumChildWindows(int hWndParent,
Delegate lpEnumFunc, int lParam);
        [DllImport("User32.dll")]
        public static extern Int32 GetWindowText(int hWnd, StringBuilder s,
int nMaxCount);
        [DllImport("User32.dll")]
        public static extern Int32 GetWindowTextLength(int hwnd);
        [DllImport("user32.dll", EntryPoint = "GetDesktopWindow")]
        public static extern int GetDesktopWindow();


        int hWnd;
        public delegate int Callback(int hWnd,int lParam);


        public Form1()
        {
            InitializeComponent();
        }
        private void button2_Click(object sender, EventArgs e)
        {

        }//

        private void button1_Click(object sender, EventArgs e)
        {
            Callback myCallBack = new Callback(EnumChildGetValue);
            hWnd = FindWindow(null, "主音量");

            if(hWnd == 0)
            {
                MessageBox.Show("Please Start Calling Window Application");
            }
            else
            {
                EnumChildWindows(hWnd,myCallBack,0);
            }


        }



        public int EnumChildGetValue(int hWnd,int lParam)
        {
            StringBuilder formDetails = new StringBuilder(256);
            int txtValue;
            string editText="";
            txtValue =GetWindowText(hWnd,formDetails,256);
            editText = formDetails.ToString().Trim();
            Console.WriteLine(" Contains text of contro:"+ editText);
            return 1;
        }

    }//
}


Thanks in advance for any help


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