TreeView 中CheckBox级联选中问题

 1 private void Init()   
 2 {   
 3     TreeViewItem tvi_0 = new TreeViewItem(); 
 4       
 5     CheckBox cb = new CheckBox();
 6 cb.Content = "所有";
 7     cb.Checked += new RoutedEventHandler((sender, e) =>{foreach (TreeViewItem item in tvi_0.Items){((item.Header as StackPanel).Children[0] as CheckBox).IsChecked = true;}});   
 8     cb.Unchecked += new RoutedEventHandler((sender, e) =>{foreach (TreeViewItem item in tvi_0.Items){((item.Header as StackPanel).Children[0] as CheckBox).IsChecked = false;}});   
 9 
10 StackPanel sp = new StackPanel(); 
11     sp.Children.Add(cb);  
12 
13 tvi_0.Name = "0"; 
14     tvi_0.Header=sp;//关键就是在 这个 Header   
15     tvi_0.IsExpanded = true;
16 
17     treeview_1.Items.Add(tvi_0);  
18 
19     TreeViewItem tviTmp = null;   
20     StackPanel sptmp = null;   
21     CheckBox cbtmp = null;   
22     for (int i = 0; i < 10; i++)   
23     {   
24    tviTmp = new TreeViewItem();   
25    sptmp = new StackPanel();   
26    cbtmp = new CheckBox();
27 
28    tviTmp.Name = "tviTmp"+i.ToString();   
29    cbtmp.Name = "cbtmp"+i.ToString();   
30    sptmp.Name = "sptmp"+i.ToString();
31 
32    cbtmp.Content = "CheckBox" + i.ToString();   
33    sptmp.Children.Add(cbtmp);   
34    tviTmp.Header = sptmp;   
35    tvi_0.Items.Add(tviTmp);   
36     }   
37 }