Custom Control Dependency Property Binding

Question

I am going insane trying to get this to work with even the most basic example. I cannot for the life of me get binding to work. Here is a super easy example that is not working for me. I MUST be doing something incorrect.

My Custom Control in my control library assembly:

public class TestControl : Control {     public static readonly DependencyProperty TestPropProperty =         DependencyProperty.Register("TestProp", typeof(string), typeof(TestControl), new UIPropertyMetadata(null));      public string TestProp     {         get { return (string)GetValue(TestPropProperty); }         set { SetValue(TestPropProperty, value); }     }      static TestControl()     {         DefaultStyleKeyProperty.OverrideMetadata(typeof(TestControl), new FrameworkPropertyMetadata(typeof(TestControl)));     } } 

And its XAML template:

<Style TargetType="{x:Type local:TestControl}">     <Setter Property="Template">         <Setter.Value>             <ControlTemplate TargetType="{x:Type local:TestControl}">                 <Border Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}">                     <StackPanel>                         <TextBlock Text="Testing..." />                         <Label Content="{Binding TestProp}" Padding="10" />                     </StackPanel>                 </Border>             </ControlTemplate>         </Setter.Value>     </Setter> </Style> 

Here's the XAML consuming the control in a wpf window with a reference to my control library:

<Grid>     <ItemsControl Name="mylist">         <ItemsControl.ItemTemplate>             <DataTemplate>                 <my:TestControl TestProp="{Binding Path=Name}" />             </DataTemplate>         </ItemsControl.ItemTemplate>     </ItemsControl> </Grid> 

And here's the code behind:

public partial class Test2 : Window {     public class TestObject : INotifyPropertyChanged     {         public event PropertyChangedEventHandler PropertyChanged;         protected void OnPropertyChanged(string PropertyName)         {             if (PropertyChanged != null)                 PropertyChanged(this, new PropertyChangedEventArgs(PropertyName));         }          private int _id;         public int id         {             get { return _id; }             set { _id = value; OnPropertyChanged("id"); }         }          private string _Name;         public string Name         {             get { return _Name; }             set { _Name = value; OnPropertyChanged("Name"); }         }     }      public Test2()     {         InitializeComponent();          mylist.ItemsSource = new TestObject[]         {             new TestObject(){ id = 1, Name = "Tedd" },             new TestObject(){ id = 2, Name = "Fred" },             new TestObject(){ id = 3, Name = "Jim" },             new TestObject(){ id = 4, Name = "Jack" },         };     } } 

Running this example gives me four instances of the control, however I only see the "Testing..." TextBlock on each. My label is never bound. What am I misunderstanding and doing incorrectly?

Answer 1

You haven't set the proper binding source. You would either have to set RelativeSource:

<Label Content="{Binding TestProp, RelativeSource={RelativeSource Mode=TemplatedParent}}" /> 

Or use TemplateBinding:

<Label Content="{TemplateBinding TestProp}"/>