Binding style for user control - wpf

Question

This is my xaml code:
<UserControl x:Class="UserControl1"
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="300" d:DesignWidth="300">
<UserControl.Resources>
<Style TargetType="TextBox" xmlns:sys="clr-namespace:System;assembly=mscorlib">
<Style.Resources>
<VisualBrush x:Key="CueBannerBrush" AlignmentX="Left" AlignmentY="Center" Stretch="None">
<VisualBrush.Visual>
<Label Content="{Binding Path=CueBannerText}" Foreground="LightGray" />
</VisualBrush.Visual>
</VisualBrush>
</Style.Resources>
<Style.Triggers>
<Trigger Property="Text" Value="{x:Static sys:String.Empty}">
<Setter Property="Background" Value="{StaticResource CueBannerBrush}" />
</Trigger>
<Trigger Property="Text" Value="{x:Null}">
<Setter Property="Background" Value="{StaticResource CueBannerBrush}" />
</Trigger>
<Trigger Property="IsKeyboardFocused" Value="True">
<Setter Property="Background" Value="White" />
</Trigger>
</Style.Triggers>
</Style>
</UserControl.Resources>
<Grid>
<TextBox TextWrapping="Wrap"/>
</Grid>
</UserControl>
I want to bind set the Label Content by code if I call the control in my project. The way I do it is like this:
Public Class UserControl1
Public Property CueBannerText As String
Get
Return _oText
End Get
Set(value As String)
_oText = value
End Set
End Property
Private _oText As String = "Search"
Public Sub New()
InitializeComponent()
Me.DataContext = Me
End Sub
End Class
If I call my control in the code With this:
<Window x:Class="MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525"
xmlns:Noru="clr-namespace:NoruTextBox;assembly=NoruTextBox">
<Grid>
<Noru:UserControl1></Noru:UserControl1>
</Grid>
</Window>
my control won't show 'Search' as the TextBox isn't selected or contains anything.

Answer 1

To do what you want, you'll either need to implement the INotifyPropertyChanged Interface in your UserControl code behind, or declare a DependencyProperty instead:
Public Shared CueBannerTextProperty As DependencyProperty = DependencyProperty.
Register("CueBannerText", GetType(String), GetType(TestView),
New PropertyMetadata("Search"))
Public Property CueBannerText() As String
Get
Return DirectCast(GetValue(CueBannerTextProperty), String)
End Get
Set
SetValue(CueBannerTextProperty, value)
End Set
End Property
Disclaimer: I just converted this to VB using an online converter, so I can't confirm its correctness.
Using a DependencyProperty will also enable you to set this value in a Style, Animation (unlikely in this situation), or a Binding:
<Noru:UserControl1 CueBannerText="{Binding SomeValue}" />