使用行为取消组合框选择更改事件

Question

I have a combobox which will load data in the data grid based on selection change. On change of combobox selection i need to check if the current data in data grid is correct or not . if not correct i would like to cancel the combobox selection change.

here is my behavior class

public class ComboBoxSelectionBehaviour : Behavior<ComboBox>
{

    public static readonly DependencyProperty SourceProperty = DependencyProperty.RegisterAttached(
        "Source",
        typeof(ViewModel),
        typeof(ComboBoxSelectionBehaviour),
        new PropertyMetadata(null));

    public ViewModel Source
    {
        get { return (ViewModel)GetValue(SourceProperty); }
        set { SetValue(SourceProperty, value); }
    }

    protected override void OnAttached()
    {
        base.OnAttached();
        AssociatedObject.SelectionChanged += AssociatedObject_SelectionChanged; ;
    }



    protected override void OnDetaching()
    {
        base.OnDetaching();
        AssociatedObject.SelectionChanged -= AssociatedObject_SelectionChanged;
    }

    private void AssociatedObject_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        var combo = sender as ComboBox;
        if (Source != null)
        {               
            // Suppress the event if errors exist
            if (!Source.IsDataCorrect())
            {                   
                e.Handled = true;
            }
        }
    }

}

even after handling the event combobox selected item is getting changed.

Please give some suggestions to solve this issue.

Answer 1

Could you simply just do a
myComboBox.SelectedIndex--

If the data is not correct? Or would this cause an infinite loop?