Question

When my usercontrol(WindowScreen) loads for the first time, my elementhost displays correctly. When I instantiate the usercontrol and pass in a different id, the elementhost doesnt get updated. Is there a reason why for this or is there a way to fix this?

Here’s my code.

WindowScreen.cs — winform:

public partial class WindowScreen : UserControl
{
    private WindowView _windowView;
    private WindowViewModel _windowViewModel = null;

    public WindowScreen(int id)
    {
        InitializeComponent();

        elementHost.Child = this.elementHost1;
        _windowViewModel = new WindowViewModel();
        _windowView = (WindowView) this.elementHost.Child;
        //_windowViewModel.LoadTypes(123); --- first load
                  _windowViewModel.LoadTypes(id); --- pass in parameter
        _windowView.DataContext = _windowViewModel;
    }
}

TestScreen.cs — winform:

public partial class TestScreen : UserControl
{
    public TestScreen()
    {
        InitializeComponent();  
    }

    private void button1_Click(object sender, EventArgs e)
    {
        WindowScreen ws = new WindowScreen(298);
    }
}

Answer 1

When you call this:

WindowScreen ws = new WindowScreen(298);

You’re creating a new WindowScreen, but never setting it to be used in your TestScreen control. You need to overwrite the current WindowScreen with this one – something like:

// This needs to be the appropriate/correct variable
this.windowScreen1 = new WindowScreen(298);