wpf dynamic change image source using timer - wpf

Question

In WPF, I have 2 images, and I need to create a blinking effect (not using opacity).
Assume that I have a.png and b.png, first step showing a.png, after 0.5 seconds, it will show b.png, then after 0.5 seconds, it will show a.png, and repeat non-stop.
I've go through the forum, but I still have no luck to get example in vb, please help.

Answer 1

You may use an appropriate animation without any code behind:
<Window.Resources>
<BitmapImage x:Key="Image1" UriSource="C:\Users\Public\Pictures\Sample Pictures\Koala.jpg"/>
<BitmapImage x:Key="Image2" UriSource="C:\Users\Public\Pictures\Sample Pictures\Jellyfish.jpg"/>
</Window.Resources>
...
<Image x:Name="image" Source="{StaticResource Image1}">
<Image.Triggers>
<EventTrigger RoutedEvent="Loaded">
<BeginStoryboard>
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Source"
Duration="0:0:1"
RepeatBehavior="Forever">
<DiscreteObjectKeyFrame Value="{StaticResource Image2}"
KeyTime="0:0:0.5"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Image.Triggers>
</Image>
Perhaps replace the Loaded event by one that better suits your needs.
If you really want to do it in code behind, you may create a DispatcherTimer with an Interval set to half a second, and in the timer's Tick event handler alternately set the image's Source property to one of the two images.

Answer 2

I'm not fit in vb.net, but in c# you can do with something like
public ImageSource GetImageSourceFromImage(Bitmap pngFile)
{
MemoryStream imageStream = new MemoryStream();
pngFile.Save(imageStream, ImageFormat.Png);
imageStream.Seek(0, SeekOrigin.Begin);
return BitmapFrame.Create(imageStream);
}
This function gives you an imagesource which you can just assign to your image-object.