Silverlight Windows Pone：编译器从listbox datatemplate内部添加自定义事件的处理程序时出错

 public delegate void TaskListItemMultiSelectViewEventHandler(TaskDataModel currentTask);
    public event TaskListItemMultiSelectViewEventHandler TaskListItemMultiSelectViewEvent;

<Grid x:Name="LayoutRoot" Background="{StaticResource PhoneChromeBrush}">
    <ListBox x:Name="TaskListBox" ItemsSource="{Binding}" MouseLeftButtonUp="TaskListBox_MouseLeftButtonUp">
        <ListBox.ItemTemplate>
            <DataTemplate>
                <mycontrol:TaskListItemControl TaskListItemMultiSelectViewEvent="TaskListItemControl_TaskListItemMultiSelectViewEvent"/>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>
</Grid>

 private void TaskListItemMultiSelectViewEvent_TaskListControl(TaskDataModel currentTask)
    {
        if (TaskListMultiSelectViewEvent != null)
            TaskListMultiSelectViewEvent(currentTask);
    }