XAML markup Extension

tag extension is a XAML language concept. { and } ) indicate a markup extension usage. "> when it is used to provide the value of the feature syntax, braces ( { and } ) indicates the markup extension usage. This usage indicates that the XAML processing system does not treat the feature value as a text string or a value that can be converted to a string as usual.

WPF ApplicationProgramThe most common markup extension in programming is binding (used for data binding expressions) and resource reference staticresource and dynamicresource. By using tag extension, you can use the feature syntax to provide a value for the property even if the property generally does not support the feature syntax. tag extension often uses the intermediate expression type to implement some functions, such as postponing a value or referencing other objects that only exist at runtime.