WPF ListBox KeyBinding未触发

Question

我有一个ListBox，我试图绑定“删除”键来删除一个项目（绑定到删除命令并更新集合），但事件永远不会被触发。更有趣的是，首次加载表单时会触发事件。我有多个列表框，我想相应地处理删除。

这是xaml代码：

<ListBox x:Name="ItemListView1" 
      ItemsSource="{Binding Path=ItemList}" 
      SelectedItem="{Binding Path=SelectedItem}">
    <ListBox.InputBindings>
        <KeyBinding Key="Delete" Command="{Binding RemoveListView1SelectedItem}" />
    </ListBox.InputBindings>
</ListBox>

这是视图模型：

    private ICommand _removeListView1SelectedItem;
    public ICommand RemoveListView1SelectedItem
    {
        get
        {
            return _removeListView1SelectedItem ?? (_removeListView1SelectedItem = new RelayCommand(param =>
            {
                if ((SelectedItem.HasValue)
                    && !ItemList.Contains(SelectedItem.Value))
                {
                    ItemList.Remove(SelectedItem.Value);
                    SelectedItem = null;
                    OnPropertyChanged("SelectedItem");
                    OnPropertyChanged("ItemList");
                }
            }));
        }
    }

This is the RelayCommand:

public RelayCommand(Action<object> execute) : this(execute, null)
        {
        }

        public RelayCommand(Action<object, object> execute) : this(execute, null)
        {
        }

        public RelayCommand(Action<object> execute, Predicate<object> canExecute)
        {
            if (execute == null)
                throw new ArgumentNullException("execute");

            _execute = execute;
            _canExecute = canExecute;
        }

        public RelayCommand(Action<object, object> execute, Predicate<object> canExecute)
        {
            if (execute == null)
                throw new ArgumentNullException("execute");

            _executeMultiParam = execute;
            _canExecute = canExecute;
        }