一般TextBox控制TextChanged事件正在运行，但在ItemsControl中，TextBox TextChanged事件未被解雇，我该怎么做。我试图通过使用以下代码来实现，但我没有得到我想要的结果。
那么，我做错了什么？
查看
<Window x:Class="SoniSoft.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:ff="clr-namespace:SoniSoft"
Title="Window1" Height="300" Width="300">
<Window.DataContext>
<ff:ViewModels/>
</Window.DataContext>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="38"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<TextBox Grid.Row="0" ff:TextBoxBehaviour.TextChangedCommand="{Binding TextChanged}" />
<ItemsControl Margin="7,0,0,0" Grid.Row="3" ItemsSource="{Binding Path=ViewModelSearchResults}" x:Name="list">
<ItemsControl.ItemTemplate>
<DataTemplate >
<Grid>
<TextBox ff:TextBoxBehaviour.TextChangedCommand="{Binding TextChanged}" Text="{Binding Path=CategoryName, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" FontSize="14" FontWeight="Normal" x:Name=" TextBoxCategoryName" />
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</Grid>
</Window>
查看模型
class ViewModels :ViewModelBase
{
public ObservableCollection<Category> AllCategorys = new ObservableCollection<Category>();
DatabaseDataContext db = new DatabaseDataContext();
private ListCollectionView _objViewModelSearchResults;
public ListCollectionView ViewModelSearchResults
{
get { return _objViewModelSearchResults; }
set
{
_objViewModelSearchResults = value;
OnPropertyChanged("ViewModelSearchResults");
}
}
public ViewModels()
{
AllCategorys.Clear();
foreach (var item in db.Categories.OrderBy(c => c.CategoryName))
{
AllCategorys.Add(item);
}
ViewModelSearchResults = new ListCollectionView(AllCategorys);
}
public ICommand TextChanged
{
get
{
// this is very lazy: I should cache the command!
return new TextChangedCommand();
}
}
private class TextChangedCommand : ICommand
{
public event EventHandler CanExecuteChanged;
public void Execute(object parameter)
{
MessageBox.Show("Text Changed");
}
public bool CanExecute(object parameter)
{
return true;
}
}
}
的DependencyProperty
class EventBehaviourFactory
{
public static DependencyProperty CreateCommandExecutionEventBehaviour(RoutedEvent routedEvent, string propertyName, Type ownerType)
{
DependencyProperty property = DependencyProperty.RegisterAttached(propertyName, typeof(ICommand), ownerType,
new PropertyMetadata(null,
new ExecuteCommandOnRoutedEventBehaviour(routedEvent).PropertyChangedHandler));
return property;
}
private class ExecuteCommandOnRoutedEventBehaviour : ExecuteCommandBehaviour
{
private readonly RoutedEvent _routedEvent;
public ExecuteCommandOnRoutedEventBehaviour(RoutedEvent routedEvent)
{
_routedEvent = routedEvent;
}
/// <summary>
/// Handles attaching or Detaching Event handlers when a Command is assigned or unassigned
/// </summary>
/// <param name="sender"></param>
/// <param name="oldValue"></param>
/// <param name="newValue"></param>
protected override void AdjustEventHandlers(DependencyObject sender, object oldValue, object newValue)
{
UIElement element = sender as UIElement;
if (element == null) { return; }
if (oldValue != null)
{
element.RemoveHandler(_routedEvent, new RoutedEventHandler(EventHandler));
}
if (newValue != null)
{
element.AddHandler(_routedEvent, new RoutedEventHandler(EventHandler));
}
}
protected void EventHandler(object sender, RoutedEventArgs e)
{
HandleEvent(sender, e);
}
}
internal abstract class ExecuteCommandBehaviour
{
protected DependencyProperty _property;
protected abstract void AdjustEventHandlers(DependencyObject sender, object oldValue, object newValue);
protected void HandleEvent(object sender, EventArgs e)
{
DependencyObject dp = sender as DependencyObject;
if (dp == null)
{
return;
}
ICommand command = dp.GetValue(_property) as ICommand;
if (command == null)
{
return;
}
if (command.CanExecute(e))
{
command.Execute(e);
}
}
/// <summary>
/// Listens for a change in the DependencyProperty that we are assigned to, and
/// adjusts the EventHandlers accordingly
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
public void PropertyChangedHandler(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
// the first time the property changes,
// make a note of which property we are supposed
// to be watching
if (_property == null)
{
_property = e.Property;
}
object oldValue = e.OldValue;
object newValue = e.NewValue;
AdjustEventHandlers(sender, oldValue, newValue);
}
}
}
class TextBoxBehaviour
{
public static readonly DependencyProperty TextChangedCommand = EventBehaviourFactory.CreateCommandExecutionEventBehaviour(TextBox.TextChangedEvent, "TextChangedCommand", typeof(TextBoxBehaviour));
public static void SetTextChangedCommand(DependencyObject o, ICommand value)
{
o.SetValue(TextChangedCommand, value);
}
public static ICommand GetTextChangedCommand(DependencyObject o)
{
return o.GetValue(TextChangedCommand) as ICommand;
}
}
答案 0 :(得分：0)
这是问题所在。您正在ItemTemplate中设置命令。因此它绑定到Category中的ListCollectionView对象。现在，这是不包含任何更改文本命令的对象。包含TextChanged命令的内容是UserControl的DataContext，您需要将其绑定到该文件。
现在有一种方法可以解决，其名称为Ancestor RelativeSource。当我使用silverlight时，它可能会有所不同，但这行代码应该可以。
修改
实际的行应该是。这是因为它是一个窗口，你需要有DataContext（viewmodel），然后是属性TextChanged：
<TextBox ff:TextBoxBehaviour.TextChangedCommand="{Binding RelativeSource={RelativeSource AncestorType={x:Type Window}, Path=DataContext.TextChanged}" />