C# 上下文菜单ICommand不';t在我的mvvm windows phone应用程序中启动
我在视图中定义了以下上下文菜单C# 上下文菜单ICommand不';t在我的mvvm windows phone应用程序中启动,c#,windows-phone-7,mvvm,windows-phone-8,contextmenu,C#,Windows Phone 7,Mvvm,Windows Phone 8,Contextmenu,我在视图中定义了以下上下文菜单 <ListBox x:Name="lstSavedTracks" ItemsSource="{Binding SavedMusicTracksDataSource}" Grid.Row="1" Margin="0,10,0,0" > <ListBox.ItemTemplate > <DataTemp
<ListBox x:Name="lstSavedTracks" ItemsSource="{Binding SavedMusicTracksDataSource}" Grid.Row="1" Margin="0,10,0,0" >
<ListBox.ItemTemplate >
<DataTemplate >
<StackPanel >
<toolkit:ContextMenuService.ContextMenu>
<toolkit:ContextMenu>
<toolkit:MenuItem Header="view" CommandParameter="{Binding}" ItemsSource="{Binding Path=PlayTrackCommand}"/>
<toolkit:MenuItem Header="delete" CommandParameter="{Binding}" Command="{Binding Path=DeleteTrackCommand}"/>
</toolkit:ContextMenu>
</toolkit:ContextMenuService.ContextMenu>
<TextBlock Foreground="White" FontSize="20" Text="{Binding TrackTitle}" TextWrapping="Wrap"></TextBlock>
<Line MinHeight="5"></Line>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
我为按钮单击事件尝试了类似的icommand绑定,它们工作得很好。但是它在上下文菜单中不起作用。这里有我遗漏的东西吗
仅供参考:适用于按钮的Icommand实现
public class DelegateCommand : System.Windows.Input.ICommand
{
private readonly Predicate<object> _canExecute;
private readonly Action<object> _execute;
public DelegateCommand(Action<object> execute)
: this(execute, null)
{
}
public DelegateCommand(Action<object> execute, Predicate<object> canExecute)
{
_execute = execute;
_canExecute = canExecute;
}
public bool CanExecute(object parameter)
{
if (_canExecute == null)
{
return true;
}
return _canExecute(parameter);
}
public void Execute(object parameter)
{
_execute(parameter);
}
public event EventHandler CanExecuteChanged;
}//end of class
公共类DelegateCommand:System.Windows.Input.ICommand
{
私有只读谓词_canExecute;
私有只读操作\u执行;
公共DelegateCommand(操作执行)
:此(执行,空)
{
}
公共DelegateCommand(操作执行,谓词canExecute)
{
_执行=执行;
_canExecute=canExecute;
}
公共布尔CanExecute(对象参数)
{
如果(_canExecute==null)
{
返回true;
}
返回_canExecute(参数);
}
public void Execute(对象参数)
{
_执行(参数);
}
公共事件处理程序CanExecuteChanged;
}//下课
您需要指出ViewModel的清晰路径和来源,如下所示:
Command=“{Binding TestVM.DeleteTrackCommand,Source={StaticResource Locator}”
希望这对您有所帮助。您是否在codeplex上查看了提供的示例?它们也可以使用ICommand,但在绑定命令时不使用“Path”属性。简单地说:Command=“{Binding DeleteTrackCommand}”我已经检查过了,但我不想使用后面的代码..这是我唯一无法应用mvvm的地方。。
public class DelegateCommand : System.Windows.Input.ICommand
{
private readonly Predicate<object> _canExecute;
private readonly Action<object> _execute;
public DelegateCommand(Action<object> execute)
: this(execute, null)
{
}
public DelegateCommand(Action<object> execute, Predicate<object> canExecute)
{
_execute = execute;
_canExecute = canExecute;
}
public bool CanExecute(object parameter)
{
if (_canExecute == null)
{
return true;
}
return _canExecute(parameter);
}
public void Execute(object parameter)
{
_execute(parameter);
}
public event EventHandler CanExecuteChanged;
}//end of class