Datacontext of nested user controls

Question

Background :-

I have a wpf view containing a combobox which gets populated by the view model using caliburn micro / ninject and mvvm pattern; this view also contains a stackpanel area. When the user selects the appropriate option from the combobox I insert the appropriate user control into the stackpanel presenting the user with a seemless transition to the related display.

Each "nested" user control which gets displayed in the stackpanel has it's own view model automatically associated by caliburn micro.

Problem :-

The "nested" user control bindings all try and refer back to the parent view model and not the view model associated with them specifically.

I can, initially, work around this by specifying :-

<UserControl.DataContext>
    <vm:UserControlSpecificViewModel/>
</UserControl.DataContext>

but this requires a parameterless constructor in the view model but I need to be able to have paremeters passed to this view model so that Ninject can inject objects such as EventAggregator.

Going around in ciricles as I am fairly new to WPF so any help would be appreciated.

Thanks.

James.

Answer 1

One way to solve your problem could be to just initialize your view model in code behind and call the appropriate constructor. If you have a dislike of code behind in your WPF applications then I suppose you could possibly just bind your view model to the IEventAggregator object.

XAML:

<UserControl1 x:Name="myUserControl">
</UserControl>

Codebehind:

public MainWindow() // Constructor for window
{
    InitializeContext();
    MyViewModel vm = new MyViewModel(...);
    myUserControl.DataContext = vm;
}