Can I set the base path outside of my application directory when binding an image source path to a relative path in WPF?

Question

So I'm trying to display an image that is ouside the path of my application. I only have a relative image path such as "images/background.png" but my images are somewhere else, I might want to choose that base location at runtime so that the binding maps to the proper folder. Such as "e:\data\images\background.png" or "e:\data\theme\images\background.png"

<Image Source="{Binding Path=ImagePathWithRelativePath}"/>

Is there any way to specify either in XAML or code behind a base directory for those images?

Answer 1

Declare a static field say BasePath in code behind

class Utility
{
    public static BasePath;
}

assign it the path that you want to use as base path

declare a converter like this:

public class RelativePathToAbsolutePathConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        //conbine the value with base path and return
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        // return whatever you want
    }
}

Update your binding to use a converter

<Window.Resources>
<local:RelativePathToAbsolutePathConverter x:Key="RelativePathToAbsolutePathConverter"/>
</Window.Resources>

<Image Source="{Binding Path=ImagePathWithRelativePath, Converter={StaticResource RelativePathToAbsolutePathConverter}}"/>