我试图让我的应用程序中的 TreeView 控件通过设置它的ItemsSource和DataContext属性来正确绑定到对象树。树按预期可视化，但TreeViewItems 数据上下文似乎包含不正确的值。
例如，我有一棵看起来像这样的树：
[-] Header
[-] Contents
[+] Item1
[+] Item2
properties
[+] Dictionary
[-] MetaDictionary
[+] TypeDef1
[+] TypeDef2
properties
项目绑定到对象的Data.Name值。但是，如果我单击任何子项Header并在事件处理程序中检查它，它会DataContext.Data.Name说Header（在适当的强制转换之后）。同样的事情MetaDictionary也发生在它的孩子身上。
这是我的课程的缩短版本：
public class CFItemTreeNode
{
private CFItem data;
public CFItem Data
{
get { return data; }
set { data = value; }
}
private ObservableCollection<CFItemTreeNode> children;
public ObservableCollection<CFItemTreeNode> Children
{
//set & get as above
}
private CFItemTreeNode parent;
public CFItemTreeNode Parent
{
//set & get as above
}
}
这是我的 XAML。几天来，我一直在搜索 SO 和网络，并将各种教程和问题的点点滴滴整合到我的这个科学怪人中。我相信这是分层模板的问题，但据我所知。
<Window x:Class="SSLowLevelBrowser.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:SSLowLevelBrowser"
Title="MainWindow"
Height="600"
Width="800"
MinHeight="100"
MinWidth="200"
Closing="MainWindowClosing">
<Window.Resources>
<Style x:Key="TreeViewItemStyle" TargetType="{x:Type TreeViewItem}">
<!-- A margin of 0 px left and 2 px top -->
<Setter Property="Margin" Value="0 2" />
<Setter Property="AllowDrop" Value="true" />
<EventSetter Event="TreeViewItem.PreviewMouseLeftButtonDown" Handler="TVI_PreviewMouseLeftButtonDown" />
<EventSetter Event="TreeViewItem.PreviewMouseMove" Handler="TVI_PreviewMouseMove" />
<EventSetter Event="TreeViewItem.PreviewDrop" Handler="TVI_PreviewDrop" />
</Style>
</Window.Resources>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="25" />
<RowDefinition Height="575*" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="390*" />
<ColumnDefinition Width="390*" />
</Grid.ColumnDefinitions>
<ToolBar Name="menuBar" Grid.ColumnSpan="2" ToolBarTray.IsLocked="True">
<Button Name="buttonOpen" Click="OpenFile">Open file</Button>
</ToolBar>
<TreeView Grid.Row="1"
Grid.Column="0"
Name="treeView"
ItemContainerStyle="{StaticResource TreeViewItemStyle}"
ItemsSource="{Binding}">
<TreeView.Resources>
<HierarchicalDataTemplate DataType="{x:Type local:CFItemTreeNode}" ItemsSource="{Binding Children}">
<Grid>
<TextBlock Text="{Binding Path=Data.Name}"
MouseLeftButtonDown="TBlock_PreviewMouseLeftButtonDown"/>
<TextBox Text="{Binding Path=Data.Name, Mode=TwoWay}"
Visibility="Collapsed"
LostFocus="TBox_LostFocus"/>
</Grid>
</HierarchicalDataTemplate>
</TreeView.Resources>
</TreeView>
<TextBox Grid.Row="1" Grid.Column="1" Name="textOutput" />
</Grid>
</Window>
我究竟做错了什么？
更新 1.这是我的事件处理程序：
private void TVI_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs args)
{
dragStartPosition = args.GetPosition(null);
dragSource = args.OriginalSource;
}
private void TVI_PreviewMouseMove(object sender, MouseEventArgs args)
{
Point currentPosition = args.GetPosition(null);
// If there is actual movement and a drag is starting
if (dragInProgress == false &&
dragStartPosition.X != -1 &&
args.LeftButton == MouseButtonState.Pressed &&
Math.Pow(currentPosition.X - dragStartPosition.X, 2) +
Math.Pow(currentPosition.Y - dragStartPosition.Y, 2) > 25)
{
dragInProgress = true;
DragDropEffects de = DragDrop.DoDragDrop(
(TreeViewItem)sender,
new DataObject(typeof(FrameworkElement), dragSource),
DragDropEffects.Move);
}
}
private void TVI_PreviewDrop(object sender, DragEventArgs args)
{
if (dragInProgress && args.Data.GetDataPresent(typeof(FrameworkElement)))
{
CFItemTreeNode dragSource =
((CFItemTreeNode)((FrameworkElement)args.Data.GetData(typeof(FrameworkElement))).DataContext);
CFItemTreeNode dropTarget =
((CFItemTreeNode)((FrameworkElement)args.OriginalSource).DataContext);
CFItemTreeNode sourceParent = dragSource.Parent;
CFItemTreeNode targetParent = dropTarget.Parent;
if (sourceParent != targetParent)
{
MessageBox.Show("Can only swap siblings.");
dragInProgress = false;
return;
}
int sourceIndex = sourceParent.Children.IndexOf(dragSource);
int targetIndex = sourceParent.Children.IndexOf(dropTarget);
if (sourceIndex != targetIndex)
{
if (sourceIndex < targetIndex)
{
sourceParent.Children.RemoveAt(targetIndex);
sourceParent.Children.RemoveAt(sourceIndex);
sourceParent.Children.Insert(sourceIndex, dropTarget);
sourceParent.Children.Insert(targetIndex, dragSource);
}
else
{
sourceParent.Children.RemoveAt(sourceIndex);
sourceParent.Children.RemoveAt(targetIndex);
sourceParent.Children.Insert(targetIndex, dragSource);
sourceParent.Children.Insert(sourceIndex, dropTarget);
}
}
dragSource = null;
dragInProgress = false;
// Reset start position to invalid
dragStartPosition = new Point(-1, -1);
}
}