How to get a dynamic resource key name programmatically?

Question

My program loads at runtime XAML file with following declaration of WPF control. The XamlReader.Load(...) method is used.

<TextBlock Name="txMy" Text="{DynamicResource ResourceKey=MyTextFromRes}"/>

It works perfect and shows text from dynamic dictionary correctly. Now I need to know NAME of KEY that resource dictionary at runtime because XAML file can be various. I need to play with related dictionary values.

How can I get a string with name of resource key ("MyTextFromRes" in this sample) at runtime in c# code?

Answer 1

Create the following helper method:

public string GetDynamicResourceKey(DependencyObject dObj, DependencyProperty dp)
{
    var value = dObj.ReadLocalValue(dp);
    var converter = new ResourceReferenceExpressionConverter();
    var dynamicResource = converter.ConvertTo(value, typeof(MarkupExtension)) as DynamicResourceExtension;
    return dynamicResource?.ResourceKey as string;
}

Now, use it with your TextBlock:

var resourceKey = GetDynamicResourceKey(txMy, TextBlock.TextProperty);

I adapted this solution from here.