use of x:static markup extension in WPF

Question

What is the use of x: static markup extension in WPF Application what should use it?

Vulpes · Answer

x:Static is what's called a XAML markup extension. It's defined in the XML namespace hence the x: prefix. What it does is to retrieve the value of a static property i.e. a property which applies to a class as a whole rather than a particular instance of it. For example: This sets the TextBlock's Background color to the background color of the active window's title bar ActiveCaption being a static property in the SystemColors class. Notice though that the background color would not be automatically updated if the ActiveCaption color were to change - in other words it takes a snapshot of the property value.