Binding to DependencyProperties in Custom Usercontrol throws exception

Question

I'm creating a Custom Usercontrol. It has two DependencyProperties I'd like to bind to Properties. When I use my UserControl and do the Binding it throws an exception:

System.Windows.Markup.XamlParseException:

"A 'Binding' cannot be set on the 'PropertyValue' property of type 'AgentPropertyControl'. A 'Binding' can only be set on a DependencyProperty of a DependencyObject.

I can't figure out what I'm doing wrong.

This is my UserControl XAML code:

<UserControl x:Class="AgentProperty.AgentPropertyControl"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d" 
             d:DesignHeight="26" d:DesignWidth="288"
             x:Name="MyUserControl">
    <Grid Name="grid">
        <StackPanel Orientation="Horizontal">
            <Label Name="lblPropertyTitle" Width="100" Margin="2" FontWeight="Bold" VerticalAlignment="Center"/>
            <TextBox Name="tbPropertyValue" Width="150" Margin="2" VerticalAlignment="Center"/>
        </StackPanel>
    </Grid>
</UserControl>

The Bindings are set in Code Behind:

public partial class AgentPropertyControl : UserControl
{
    public readonly static DependencyProperty PropertyTitleDP = DependencyProperty.Register("PropertyTitle", typeof(string), typeof(Label), new FrameworkPropertyMetadata("no data"));
    public readonly static DependencyProperty PropertyValueDP = DependencyProperty.Register("PropertyValue", typeof(string), typeof(TextBox), new FrameworkPropertyMetadata("no data"));
    
    public string PropertyTitle
    {
        set { SetValue(PropertyTitleDP, value); }
        get { return (string) GetValue(PropertyTitleDP); }
    }
    
    public string PropertyValue
    {
        set { SetValue(PropertyValueDP, value); }
        get { return (string)GetValue(PropertyValueDP); }
    }

    public AgentPropertyControl()
    {
        InitializeComponent();

        lblPropertyTitle.SetBinding(Label.ContentProperty, new Binding() {Source = this, Path = new PropertyPath("PropertyTitle")});
        tbPropertyValue.SetBinding(TextBox.TextProperty, new Binding() { Source = this, Path = new PropertyPath("PropertyValue"), Mode = BindingMode.TwoWay });
    }
}

And the usage of my UserControl:

<AgentProperty:AgentPropertyControl PropertyTitle="ID" PropertyValue="{Binding Path=ID}" Grid.ColumnSpan="2"/>

Its DataContext is set on the Grid that contains the UserControl.

Why is it throwing the exception and how can I solve it?

Piotr Auguscik Piotr Auguscik · Accepted Answer · 2011-12-28T09:48:32

3rd argument of DependencyProperty.Register is owner type. In your case it should be your control:

public readonly static DependencyProperty PropertyTitleDP = DependencyProperty.Register("PropertyTitle", typeof(string), typeof(AgentPropertyControl), new FrameworkPropertyMetadata("no data"));
public readonly static DependencyProperty PropertyValueDP = DependencyProperty.Register("PropertyValue", typeof(string), typeof(AgentPropertyControl), new FrameworkPropertyMetadata("no data"));

Binding to DependencyProperties in Custom Usercontrol throws exception

1 Answers