CODEWITHSUNDEEP
c#wpfxamlinheritanceuser-controls
Th1sD0t
Th1sD0t

Reputation: 1129

Creating a Base-UserControl

I've created several UserControls which got some common Properties. Is it possible to create a base-UserControl from which the concrete ones can derive?

Base Class:

public class LabeledControlBase : UserControl {
    public string ControlWidth {
        get { return (string)GetValue(ControlWidthProperty); }
        set { SetValue(ControlWidthProperty, value); }
    }

    // Using a DependencyProperty as the backing store for ControlWidth.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty ControlWidthProperty =
        DependencyProperty.Register("ControlWidth", typeof(string), typeof(LabeledControlBase), new PropertyMetadata("Auto"));
}

Concrete Class:

public partial class LabeledTextBox : Base.LabeledControlBase {
    public string LabelText {
        get { return (string)GetValue(LabelTextProperty); }
        set { SetValue(LabelTextProperty, value); }
    }
    // Using a DependencyProperty as the backing store for LabelText.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty LabelTextProperty =
        DependencyProperty.Register("LabelText", typeof(string), typeof(LabeledTextBox), new PropertyMetadata(null));

    public string TextBoxText {
        get { return (string)GetValue(TextBoxTextProperty); }
        set { SetValue(TextBoxTextProperty, value); }
    }
    // Using a DependencyProperty as the backing store for TextBoxText.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty TextBoxTextProperty =
        DependencyProperty.Register("TextBoxText", typeof(string), typeof(LabeledTextBox), new PropertyMetadata(null));

What I want to achive: I want to be able to set the "ControlWidth" Property on any UserControl which derives from "LabeledControlBase".

What is the problem: The way I realized it my LabeledTextBox does not recognize GetValue and SetValue Methods although it inherits from LabeledControlBase which derives from UserControl. When changing Base.LabeledControlBase to UserControl everything works just fine (except I can not access my commonly used Properties).

Upvotes: 3

Views: 927

Answers (1)

Petter Hesselberg
Petter Hesselberg

Reputation: 5518

Since I haven't seen LabeledTextBox.xaml I can't be sure, but I suspect your XAML is somehow wrong -- perhaps using UserControl as the root? The XAML should look something like this:

<wpf:LabeledControlBase
    x:Class="WPF.LabeledTextBox"
    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"
    xmlns:wpf="clr-namespace:WPF"
    x:Name="self"
    mc:Ignorable="d" 
    d:DesignHeight="300" d:DesignWidth="300">
    <Grid>
        <TextBox Text="{Binding ElementName=self, Path=ControlWidth}" />
    </Grid>
</wpf:LabeledControlBase>

...with LabeledControlBase as the root. This lets me use a LabeledTextBox control in a page:

<wpf:LabeledTextBox ControlWidth="Hi" />

(ControlWidth's intended semantics are likely not what I'm doing with it; this is just to verify that things work. And they do.)

Upvotes: 1

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