为什么我看不到PNG文件中的列表框？

Question

我想要什么
我想在WP7.5中显示一个自定义活动切片，一个文本块和一个带有4个字符串作为其listitem的列表框。因此，我创建了一个包含所有内容的图像并将其显示为活动图块的背景。

我的代码

 //prepare the background 
     WriteableBitmap bmp = new WriteableBitmap(173, 173); 
     BitmapImage logo = new BitmapImage(new Uri("/images/tile/SecondaryTile.png", UriKind.Relative));    
     Image img = new Image { Source = logo }; 

     // Force the bitmapimage to load it's properties so the transform will work 
     logo.CreateOptions = BitmapCreateOptions.None; 

     //create a textblock 
     TextBlock taskNumberShow = new TextBlock(); 
     taskNumberShow.Foreground = new SolidColorBrush(Colors.White); 
     taskNumberShow.FontSize = 35; 
     taskNumberShow.HorizontalAlignment = HorizontalAlignment.Center; 
     taskNumberShow.FontFamily = (FontFamily)Application.Current.Resources["PhoneFontFamilySemiBold"]; 
     taskNumberShow.Text = "35"; 

     //define the position 
     TranslateTransform tt1 = new TranslateTransform(); 
     tt1.X = 45; 
     tt1.Y = 7; 
     bmp.Render(taskNumberShow, tt1); 

     //create a listbox 
     ListBox listBox1 = new ListBox(); 
     listBox1.Height = 100; 
     listBox1.Width = 173; 
     listBox1.HorizontalAlignment = HorizontalAlignment.Center; 
     //listBox1.VerticalAlignment = VerticalAlignment.Bottom; 
     //listBox1.Margin = new Thickness(50, 150, 0, 0); 

     //put a string array in the listbox, the length of this array is 4 
     for (int i=0; i < TaskList.Length; i++) 
     { 
      //先生成一堆textBlock 
      TextBlock txtBlk = new TextBlock(); 
      txtBlk.Name = "txtBlk" + i.ToString(); 
      txtBlk.Text = TaskList[i]; 
      txtBlk.FontSize = 17; 
      txtBlk.Width = 173; 
      txtBlk.TextWrapping = TextWrapping.NoWrap; 
      txtBlk.Foreground = new SolidColorBrush(Colors.White); 
      listBox1.Items.Add(txtBlk); 
     } 

     //define the position 
     tt1.X = 0; 
     tt1.Y = 40; 
     bmp.Render(listBox1, tt1); 


     //add the backgroundpic 
     tt1.X = 0; 
     tt1.Y = 0; 
     bmp.Render(img, tt1); 
     bmp.Invalidate(); 

     ExtendedImage extendImage = bmp.ToImage(); 

结局是什么
我可以看到文本块，但我看不到列表框中。我试图直接分配下面

for (int i=0, i<TaskList.Length, i++) 
{ 
Listbox1.Items.Add(TaskList[i]); 
} 

使用的代码的字符串数组（任务列表[]）到列表框的项，但结果是我不能看到这一点。

我该如何解决这个问题？为什么我看不到图片中的列表框？

Answer 1

这可能与ListBox的虚拟性质有关。一种选择是将ItemsPanel设置为StackPanel。另外，也许更简单的方法是只使用一个StackPanel

//create a StackPanel 
    StackPanel stackPanel1 = new StackPanel(); 
    stackPanel1.Height = 100; 
    stackPanel1.Width = 173; 
    stackPanel1.HorizontalAlignment = HorizontalAlignment.Center; 

    //put a string array in the listbox, the length of this array is 4 
    for (int i=0; i < TaskList.Length; i++) 
    { 
     //先生成一堆textBlock 
     TextBlock txtBlk = new TextBlock(); 
     txtBlk.Name = "txtBlk" + i.ToString(); 
     txtBlk.Text = TaskList[i]; 
     txtBlk.FontSize = 17; 
     txtBlk.Width = 173; 
     txtBlk.TextWrapping = TextWrapping.NoWrap; 
     txtBlk.Foreground = new SolidColorBrush(Colors.White); 
     stackPanel1.Children.Add.Add(txtBlk); 
    } 

我也建议把所有的控件到像网格父容器和渲染网格为一体。