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WPF Prism Unity Container. Setting keyboard focus on usercontrol or usercontrol grid parent

I'm working on a project that utilizes WPF, using the Prism library and Unity Container.

I have a mainwindow, which contains a mainviewmodel control which in turn is populated by a collection of user controls.

My goal is to set keyboard focus to the mainviewmodel where I have an EventTrigger InvokeCommandAction which reacts to keyeventsargs...

Currently the only way the command is fired if I use a textbox within the control (or child controls). My goal is to have the mainviewmodel control or grid get and preserve keyboard focus.

Any tips would be appreciated! //Nathan

Solution

  • Either not understanding your question correctly or you should review the basic concepts of MVVM in a WPF implementation.

    The View is the WPF controls.
    WPF Window/UserControl files contain WPF markup which is the View.

    Controls in a view leverage DataBindings to the DataContext property of either the control itself or the parent containing control (which it will inherit).

    DataContext property is set to an instance of an object that is the ViewModel. It contains properties to hold values and commands to execute actions.

    So conceptually there is no "mainviewmodel control", there is a MainView which contains controls and may in this case have its DataContext property set to an instance o MainViewModel. (hence my confusion)

    Finally, while it is possible and some might even recommend writing UI rules/logic in a view model I haven't found much benefit in it.

    You are much better off putting UI logic in the XAML or in the MinView code behind. You can still access the MainViewModel in the code behind by casting the MainView.DataContext property as a MainViewModel.

    So for example: MainView.KeyDown event can be wired up to call MainViewModel.CommandX.Execute();