C#控件刷新

 int count = ;
 int success_count = ;
 foreach (string gen in fn_gen)
 {
     //MessageBox.Show(gen);
     Bitmap Bi = new Bitmap(gen);  //使用打开的图片路径创建位图对像
     Image Image = Bi;
     if (Image.Width >=  && Image.Height >= )
     {
         string destinationFile = result + gen.Substring(gen.LastIndexOf(@"\"), gen.Length - gen.LastIndexOf(@"\"));
         bool isrewrite = true; // true=覆盖已存在的同名文件,false则反之
         System.IO.File.Copy(gen, destinationFile, isrewrite);
         success_count++;
         this.Txt_Count.Refresh();
         this.Txt_Count.Text = success_count.ToString() + "/" + count.ToString();
         Application.DoEvents();// Application.DoEvents()的作用：处理所有的当前在消息队列中的Windows消息。
         System.Threading.Thread.Sleep();
     }
     count++;
     Bi = null;
     System.GC.Collect();
 }