如何使用MVVM灯从CustomControl引用视图模型

Question

I'm used to setting the datacontext of a UserControl in xaml to a viewmodel using the MVVM-light locator. eg:

DataContext="{Binding SplashMainViewModel, Mode=OneWay, Source={StaticResource Locator}}"

This is done in the view's markup in xaml.

How does one go about setting the datacontext of a CustomControl to a viewmodel? In VS the custom control is created with the following:

    public class CustomControl1 : Control
    {
        static CustomControl1()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(CustomControl1),new FrameworkPropertyMetadata(typeof(CustomControl1)));
        }
    }

But it doesn't have the usual xaml markup.

Answer 1

Try something like:

public class CustomControl1 : Control
{
    static CustomControl1()
    {
        DefaultStyleKeyProperty.OverrideMetadata(typeof(CustomControl1),new FrameworkPropertyMetadata(typeof(CustomControl1)));
    }

    public override void OnApplyTemplate()
    {
          base.OnApplyTemplate();
          DataContext = ((MyLocatorType)Resources["Locator"]).SplashMainViewModel;
    }
}

... or set it in the XAML of the template ( Themes\\Generic.xaml ).

Answer 2

Rico Suter's demonstrates how to set CustomControl1's DataContext for all instances of CustomControl1. I'm guessing this is what you want to do.

You could use your normal approach to set the DataContext on a specific instance of CustomControl1 (in the xaml where it is declared). I'm guessing this is not what you want to do but I'm including for completeness. If there is only one instance of CustomControl1 this may be more convenient.