GalaSoft.MvvmLight.EventToCommand<T> args always null

Question

I have a base class derived from MvvmLight.ViewModelBase with additional responsibilities to handle object selections. This class defines a RelayCommand<MouseButtonEventArgs> property which is bound in the View:

        <i:Interaction.Triggers>
            <i:EventTrigger EventName="MouseDown">
                <galaxcmd:EventToCommand Command="{Binding SelectCommand,Mode=OneWay}" PassEventArgsToCommand="True"  />
            </i:EventTrigger>
        </i:Interaction.Triggers>

This view is used multiple times inside a containing view that I now need to handle mousedowns too. My issue arises because I don't want the container to handle mousedown if it was handled by a contained view. I thought the PassEventArgsToCommand was my solution to this problem because I planned a child VM to just set MouseButtonEventArgs.Handled = true . Unfortunately, the MouseButtonEventArgs argument is always null. Just in case, I also tried RoutedEventArgs and even EventArgs, but they're all null too.

What am I doing wrong with EventToCommand (or EventTrigger?)?

Answer 1

您可以在此处找到基于EventToCommand的经过修改的EventToCommand实现，您可以在其中将Eventargs设置为CommandParameter并停止事件路由。