Question

I have an Image control that is supposed to do a slide show.
Here are the binding I used to achieve this:

    Binding mapBinding = new Binding();
    mapBinding.Source = slideView;
    mapBinding.Path = new PropertyPath("ImageDrawing");
    sliderImage.SetBinding(System.Windows.Controls.Image.SourceProperty, mapBinding);

And a class SlideImage

public class SlideImage : INotifyPropertyChanged {
    public ImageSource ImageDrawing{get;set;} 
    public void ChangeImage(){
         // Load another image
         // Update ImageDrawing
         // Fire property changed event
    }
    public event PropertyChangedEventHandler PropertyChanged;
}

I found many examples on the net using the UpdateSourceTrigger to listen for data source changes. The only problem is the Image control does not have that property.

How do I hook up my sliderImage control to update on SlideImage.PropertyChanged?

Answer 1

It probably will update automatically, if you’re actually calling PropertyChanged when calling the setter of ImageDrawing.

You aren’t firing PropertyChanged for your ImageDrawing property in the code you’ve provided. Try this:

private ImageSource imageDrawing;
public ImageSource ImageDrawing
{
    get { return imageDrawing; }
    set
    {
        imageDrawing = value;
        RaisePropertyChanged("ImageDrawing");
    }
}

private void RaisePropertyChanged(string propertyName)
{
    if(PropertyChanged != null)
    {
        PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
    }
}