GroupBOx内容WPF

Question

我有GroupBox名称groupBox1，它包含StackPanel。在StackPanel中，我有很多ChechBoxes。在我xaml.cs我想这些的CheckBox，但是当我写了下面的代码行，我得到一个零：

int n = VisualTreeHelper.GetChildrenCount(groupBox1); 

如果我写了下面的代码行我得到exeption：

“指定索引超出范围或 索引处的子项为空。如果VisualChildrenCount为 返回零，表明 Visual没有子项，请不要拨打 参数 name：index实际值为0。

Visual v = (Visual)VisualTreeHelper.GetChild(groupBox1, 0); 

这意味着，我的groupBox1没有任何孩子....但什么StackPanel的？

我有这个功能应该itarete过的VisualTree，它看起来像这样：

private void VisualChildren (Visual myVisual) 
{   
    for (int i = 0; i < VisualTreeHelper.GetChildrenCount(myVisual); i++) 
    { 
     Visual childVisual = (Visual)VisualTreeHelper.GetChild(myVisual, i); 

     //Some operations 

     VisualChildren(childVisual); 
    } 
} 

它并不需要在groupBox1的StackPanel ......

谁能告诉我怎样才能到达那些CheckBoxes？
谢谢。

---

这是我的XAML：

<Window x:Class="MyNamespace.MyClass" 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    Title="Test" Height="300" Width="300" Loaded="Window_Loaded" Name="win1"> 
    <Grid Name="grid1"> 
     <GroupBox Header="GroupBox" Margin="0,0,95,124" Name="groupBox1"> 
      <StackPanel Orientation="Vertical" Height="105"> 
       <CheckBox Height="Auto" Name="checkBox4" Width="Auto" Margin="2">CheckBox</CheckBox> 
       <CheckBox Height="Auto" Name="checkBox2" Width="Auto" Margin="2">CheckBox</CheckBox> 
       <CheckBox Height="Auto" Name="checkBox3" Width="Auto" Margin="2">CheckBox</CheckBox> 
       <CheckBox Height="Auto" Name="checkBox5" Width="Auto" Margin="2">CheckBox</CheckBox> 
       <CheckBox Height="Auto" Name="checkBox1" Width="Auto" Margin="2">CheckBox</CheckBox> 
       <CheckBox Height="Auto" Name="checkBox6" Width="Auto" Margin="2">CheckBox</CheckBox> 
       <CheckBox Height="Auto" Name="checkBox7" Width="Auto" Margin="2">CheckBox</CheckBox> 
      </StackPanel> 
     </GroupBox> 
     <WrapPanel Orientation="Horizontal" Name="wrap2" Margin="8" HorizontalAlignment="Center" VerticalAlignment="Bottom"> 
      <Button Margin="5" Height="23" Name="button1" VerticalAlignment="Bottom" HorizontalAlignment="Right" Width="75">Button</Button> 
      <Button Margin="5" Height="23" HorizontalAlignment="Right" Name="button2" VerticalAlignment="Bottom" Width="75">Button</Button> 
      <Button Margin="5" Height="23" HorizontalAlignment="Right" Name="button3" VerticalAlignment="Top" Width="75">Button</Button> 
      <Button Margin="5" Height="23" HorizontalAlignment="Right" Name="button4" VerticalAlignment="Top" Width="75">Button</Button> 
      <Button Margin="5" Height="23" HorizontalAlignment="Right" Name="button5" VerticalAlignment="Top" Width="75">Button</Button> 
      <Button Margin="5" Height="23" HorizontalAlignment="Right" Name="button6" VerticalAlignment="Top" Width="75">Button</Button> 
     </WrapPanel> 
    </Grid> 
</Window> 

，这是代码：

public partial class Window1 : Window 
{ 
    public Window1() 
    { 
     InitializeComponent(); 
     try 
     { 
      VisualChildren(grid1); 
     } 
    } 

    private void VisualChildren(Visual myVisual) 
    { 
     for (int i = 0; i < VisualTreeHelper.GetChildrenCount(myVisual); i++) 
     { 
      Visual childVisual = (Visual)VisualTreeHelper.GetChild(myVisual, i); 
      System.Windows.Forms.MessageBox.Show(childVisual.ToString()); 
      VisualChildren(childVisual); 
     } 
    } 
} 

Answer 1

显然的问题是，你正在试图获得一个元素的视觉儿童它得到前加载。那时视觉树还没有被创作。请尝试订阅到Loaded事件你的小组箱子，在事件处理程序获得的视觉孩子：

public partial class Window1 : Window 
{ 
    public Window1() 
    { 
     InitializeComponent(); 

     Loaded += OnLoaded; 
    } 

    private void OnLoaded(object sender, EventArgs e) 
    { 
     VisualChildren(grid1); 
    } 

    ... 
}