Click event on textbox inside a usercontrol WPF

Question

Hello,
I'am a beginner in WPF and then i need your help!
I try to make a usercontrol which contains a textbox. I wish I could handle the click on the texbox to eg display a popup. So I add a property ClickCommand (which would be an onclick) because it does not exist on the textbox and then to be able to bind on the
event, so I used the DependencyProperty. But when I click on the textbox, no callback on the command binded. What is wrong?
Xaml part of the textbox inside my usercontrol
<TextBox x:Name="Test" Cursor="{Binding FieldCursor}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="PreviewMouseLeftButtonDown">
<prism:InvokeCommandAction Command="{Binding ClickCommand}" />
</i:EventTrigger>
</i:Interaction.Triggers>
</TextBox>
Binding part to manage the DependencyProperty
public static readonly DependencyProperty ClickCommandProperty = DependencyProperty.Register("ClickCommand",
typeof(DelegateCommand<object>),
typeof(VariableControl),
new FrameworkPropertyMetadata((DelegateCommand<object>)null),
new ValidateValueCallback(IsValidClickCommand));
public DelegateCommand<object> ClickCommand
get { return (DelegateCommand<object>)this.GetValue(ClickCommandProperty); }
set { this.SetValue(ClickCommandProperty, value); }
public static bool IsValidClickCommand(object value)
DelegateCommand<object> v = (DelegateCommand<object>)value;
return true;

Answer 1

The ClickCommand should be a property of the DataContext of the TextBox for the binding to work. If you define the dependency property in the code-behind of the UserControl class, you need to set the DataContext of the TextBox to the user control:
public partial class VariableControl : UserControl
public VariableControl()
InitializeComponent();
Test.DataContext = this;
public static readonly DependencyProperty ClickCommandProperty = DependencyProperty.Register("ClickCommand",
typeof(DelegateCommand<object>),
typeof(VariableControl),
new FrameworkPropertyMetadata((DelegateCommand<object>)null),
new ValidateValueCallback(IsValidClickCommand));
public DelegateCommand<object> ClickCommand
get { return (DelegateCommand<object>)this.GetValue(ClickCommandProperty); }
set { this.SetValue(ClickCommandProperty, value); }
public static bool IsValidClickCommand(object value)
DelegateCommand<object> v = (DelegateCommand<object>)value;
return true;
Or in the XAML:
<TextBox x:Name="Test" Cursor="{Binding FieldCursor}" DataContext="{Binding Path=., RelativeSource={RelativeSource AncestorType=UserControl}}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="PreviewMouseLeftButtonDown">
<prism:InvokeCommandAction Command="{Binding ClickCommand}" />
</i:EventTrigger>
</i:Interaction.Triggers>
</TextBox>
Hope that helps.
Please remember to mark helpful posts as answer to close your threads and then start a new thread if you have a new question. Please only ask one question per thread.