c#重载窗体关闭事件,遍历文件件下所有文件（及子目录）,

 C#中重载窗体关闭事件

 protected override void OnFormClosing(FormClosingEventArgs e)
        {
            if (MessageBox.Show("你确认要退出该程序吗？", "提示", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button2) == DialogResult.Yes)
                base.OnFormClosing(e);
            else
                e.Cancel = true;
        }

 

          
         public void button1_Click(object sender, EventArgs e)
        {
            folderBrowserDialog1.RootFolder = Environment.SpecialFolder.MyComputer;
            folderBrowserDialog1.Description = "请选包含待清理Dwg文件的文件夹:";
            try
            {
                if (folderBrowserDialog1.ShowDialog() == DialogResult.OK)
                {
                    listBox1.Items.Clear();
                    textBox1.Text = folderBrowserDialog1.SelectedPath;
                    DirectoryInfo di = new DirectoryInfo(textBox1.Text);

                    //获得目录信息

                    FileInfo[] fiA = di.GetFiles("*.dwg", SearchOption.AllDirectories);//获得该目录下的所有文件

                    //di.GetFiles(searchPattern, SearchOption.TopDirectoryOnly)

                  //获取目录下文件（但不包括子目录）

                    for (int i = 0; i < fiA.Length; i++)
                    {
                        listBox1.Items.Add(fiA[i].FullName);
                    }
                    label1.Text = "目录中共" + fiA.Length.ToString() + "个dwg文件！";
                    if (fiA.Length == 0)
                        MessageBox.Show("选择的文件夹中没有Dwg文件！");
                }
            }
            catch(Exception  ee)

            {
                MessageBox.Show (ee.ToString ());
            }

        }