How can I turn binding errors into runtime exceptions?

Just as there is "treat warning as errors" set in our projects to catch early possible problems, I would love to have a runtime exception to catch them early.

I have recently been bit by this problem and I would have been glad to have this.

Can it be done? And if yes, how?

Solution 1:

You could hook into the PresentationTraceSources collection with your own listener:

public class BindingErrorListener : TraceListener
{
    private Action<string> logAction;
    public static void Listen(Action<string> logAction)
    {
        PresentationTraceSources.DataBindingSource.Listeners
            .Add(new BindingErrorListener() { logAction = logAction });
    }
    public override void Write(string message) { }
    public override void WriteLine(string message)
    {
        logAction(message);
    }
}

and then hook it up in code-behind

public partial class MainWindow : Window
{
    public MainWindow()
    {
        BindingErrorListener.Listen(m => MessageBox.Show(m));
        InitializeComponent();
        DataContext = new string[] { "hello" };
    }
}

Here is the XAML with a binding error

    <Grid>
    <TextBlock Text="{Binding BadBinding}" />
</Grid>

Solution 2:

I implemented a solution very similar to the one proposed by Dean Chalk:

1. Derived a TraceListener that throws instead of logging
2. Added that listener to PresentationTraceSources.DataBindingSource

Please see the complete solution on GitHub, it includes a demo application and a unit test project.