Question

I need the instance of view in viewmodel to manipulate the element of view from ViewModel. how can I pass the instance of current View (sender) to ViewModel.

<UserControl...>
    <br>...<br>
    <Button x:Name="btnRemove" Width="100" Height="30" 
        Content="Remove" Margin="5" Visibility="Hidden"  
        Command="{Binding CellFrame.WidgetRemoveCommand, Mode=OneWay, Source={StaticResource Locator}}" 
        CommandParameter="{Binding Mode=OneWay}" />
    <br>...<br>
</UserControl>

This passes the instance of viewModel in WidgetRemoveCommand. How to pass the Intance of Usercontrol.

Thanks

Answer 1

In this scenario, you can simply bind the Command property in constructor of user control. Have a locator class which keeps pointer to CellFrame view model.

btnRemove.Command = some_locator_class.static_method.WidgetRemoveCommand;
btnRemove.CommandParameter = this;

The CellFrame view model can have a RelayCommand named WidgetRemoveCommand like below:

RelayCommand<CellFrame> WidgetRemoveCommand 

Now, this relay command has delegate method defined like below:

public void WidgetRemoveAction(CellFrame cell)
{
    // here you get it! 
}

So, the trick is to send the ‘this’ in command parameter.

Hope this helps.