WPF: Binding a Label to a class property

Question

I\'m trying to get the content of a label to bind to the string property of a class instance without much success.

XAML:

Answer 1

Or give your Window a name: like NameOfWindow and use a ElementName binding:

Content="{Binding ElementName=NameOfWindow, Path=MyFoo.W1}"

Complete sample XAML:

<Window x:Class="WPFBindingTest.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1" Height="300" Width="300" Name="NameOfWindow">    
<Grid>        
    <Label Height="28" Margin="12,55,106,0" Name="label1" Background="Bisque" Content="{Binding ElementName=NameOfWindow, Path=MyFoo.W1}" VerticalAlignment="Top" />
    <Label Height="28" Margin="12,12,106,0" Name="label2" Background="Bisque" Content="{Binding ElementName=NameOfWindow, Path=MyFoo.W2}"  VerticalAlignment="Top" />
    <Button Height="23" HorizontalAlignment="Right" Margin="0,0,32,48" Name="button1" VerticalAlignment="Bottom" Width="89" Click="button1_Click">Set Properties</Button>
</Grid> 

Answer 2

You may make your MyFoo a dependency property and set the DataContext to your Window1 instance:

<Window DataContext="{Binding RelativeSource={RelativeSource Self}}" ...>

See this article for more details.

Making MyFoo a dependency property is not compulsory. it may work with just a property if you set the property value before assigning the DataContext. (But never with a field.) However if you want the labels to pick up the changing values of W1 and W2 (or you don't know/care if the values are set before or after assigning the DataContect), you need Foo to be either a DependencyObject, or implement interface INotifyPropertyChanged.