Using XamlReader for controls that does not have a default constructor

Question

I have some string representations of Xaml objects, and I want to build the controls. I\'m using the XamlReader.Parse function to do this. For a simple control such as Button th

Answer 1

It's a "feature" of the XAML language, it is declarative and doesn't know anything about constructors.

People use ObjectDataProvider in XAML to "translate" and wrap instances of classes that do not have a parameterless constructor (it's also useful for data binding).

In your case the XAML should look approximately like this:

<ObjectDataProvider ObjectType="Stroke">
    <ObjectDataProvider.ConstructorParameters>
        <StylusPointsCollection>
            <StylusPoint X="100" Y="100"/>
            <StylusPoint X="200" Y="200"/>
        </StylusPointsCollection>
    </ObjectDataProvider.ConstructorParameters>
</ObjectDataProvider>

And the code should be:

var stroke = (Stroke) ((ObjectDataProvider)XamlReader.Parse(xamlStr)).Data;

HTH.