Dynamically switching between canvases wpf - wpf

Question

I have multiple canvas images of different types (image source, geometry, path) and wish to only show 1 depending on a string binding.
whats the best way to do this?
i'd like it to be reusable so i can place this code inside a user control and then have many of these images around the app and i select which 1 is shown.
Like so:
<CanvasImage Image="Pie"/>
<CanvasImage Image="Dog"/>
Would it be too computationally expensive to have them all declared in the user control view and use visibility bindings
Pie canvas example:
<canvas>
<Data ="m24,98,07">
</canvas>
Dog canvas example:
<canvas>
<image source="">
<canvas>

Answer 1

This converter return an image source directly, depending on the value it receives.
namespace TestTreeView.Views
{
public class StringToImageConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
string file = "";
string v = value as string;
switch (v)
{
case "Pie":
file = #".\path\to\your\pie.jpg";
break;
case "Dog":
file = #".\path\to\your\dog.jpg";
break;
default:
return null;
}
return new BitmapImage(new Uri(file, UriKind.RelativeOrAbsolute));
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
}
Usage in XAML:
<Window xmlns:local="clr-namespace:YourNamespace.Views" ...>
<Window.Resources>
<local:StringToImageConverter x:Key="stringToImageConverter"/>
</Window.Resources>
<Grid>
<Canvas>
<Image Source="{Binding YourString, Converter={StaticResource stringToImageConverter}}"/>
</Canvas>
</Grid>
</Window>
Original answer
I think you need to use a Converter.
It will take a ConverterParameter, a String, that will tell what the binded value is expected to be, and return a Visiblity to indicate if the canvas should be visible or not.
namespace YourNamespace.Views
{
public class StringToCanvasVisibilityConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
string v = value as string;
string p = parameter as string;
return (v != null && p != null && v == p) ? Visibility.Visible : Visibility.Collapsed;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
}
Usage in XAML:
<Window xmlns:local="clr-namespace:YourNamespace.Views" ...>
<Window.Resources>
<local:StringToVisibilityConverter x:Key="stringToVisibilityConverter"/>
</Window.Resources>
<Grid>
<Canvas Visibility="{Binding YourString, Converter={StaticResource stringToVisibilityConverter}, ConverterParameter=Pie}"/>
<Canvas Visibility="{Binding YourString, Converter={StaticResource stringToVisibilityConverter}, ConverterParameter=Dog}"/>
</Grid>
</Window>