Question

Assuming we have such control:

public partial class MyUserControl : UserControl {     public MyUserControl() {         InitializeComponent();     }      public string Foo { get; set; } } 

How can I set ‘Foo’ property value declaratively in MyUserControl.xaml?

<UserControl x:Class='Test.MyUserControl'     xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'     xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>      <!-- Looking for some thing like this -->     <Foo>Hola</Foo>  </UserControl> 

To be more clear: How can I set in XAML a value for the property defined in code-behind.

Answer 1

This can only be achieved in xaml by inheritance:

You are providing an implementation for your control. So the only way to achieve a value in xaml for your control is through inheritance.

Your second UserControl will look like this:

<Test:MyUserControl x:Class='Test.MyUserControl'     xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'     xmlns:Test='clr-namespace:Test'     xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>      <Test:MyUserControl.Foo>Hola</Test:MyUserControl.Foo>  </Test:MyUserControl> 

or:

<Test:MyUserControl x:Class='Test.MyUserControl'     xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'     xmlns:Test='clr-namespace:Test'     xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'     Foo='Hola'>  </Test:MyUserControl>