WPF User Controls and DataBinding?

You bind the DataSource to the Button, not to your IconButton.

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I guess I'm a bit stuck on the mechanism of WPF DataBinding. Up to now I've thought of it as this : Any target of a DataBinding has to be a DependencyProperty. Keeping that in mind, I designed a very simple button-based UserControl like the following (boiled down to the most necessary parts): XAML C# using System.

Windows; using System.Windows. Controls; using System.Windows. Media; namespace MyNamespace { public partial class IconButton : Button { public string Text { get { return this.tbText.

Text; } set { this.tbText. Text = value; } } public ImageSource ImageSource { get { return (ImageSource)GetValue(ImageSourceProperty); } set { SetValue(ImageSourceProperty, value); } } public static readonly DependencyProperty ImageSourceProperty = DependencyProperty. Register("ImageSource",typeof(ImageSource), typeof(IconButton)); public IconButton() { InitializeComponent(); } } } Using this Control is fairly straightforward: The Visual Studio Designer displays the button and the text, but refuses to evaluate the dependency property 'ImageSourceProperty'.

The same happens when I implement 'Text' as a DependencyProperty. Why does it do this? And also, why do I need a regular 'ImageSource' at all?

If I remove this Property from my code, the VS XAML Editor (where using the control) will Tooltip the ImageSource Property with "System.Windows. DependencyProperty MyNamespace.IconButton. ImageSourceProperty" (instead of the regular property description), which means it can resolve the dependency property correctly, nevertheless I can't set any value this way ("Attached Property has no setter").

Why can I only set the value of a dependecy property via a regular property from xaml? Finally, I have another problem. To simplify explanations, I use an Article-Category setup in this example.

The UI is supposed to enable users to recategorize shop articles. I can use this to alter my articles (i.e. Set new categories) by making a selection in cbCategories, but when selecting an article from lvArticles, cbCategories is not automatically set to the related Category.

Is there anything wrong with what I'm doing or is this yet another WPF anomaly? Thanks a lot in advance for any hints... EDIT Since yesterday, I haven't been thinking about anything but this weird ComboBox behavior. The first flaw I found in my code was the missing override of the Equals method in the ViewModels that went into the ComboBox.

As a result, there was no chance for anything ever being the SelectedItem - all comparisons of the ItemSource's elements with the SelectedItem resulted in a neat 'False'. I've now patched this up. But in my Master-Detail-View, the Details still won't snap to the correct values when changing the selected Master Record.

YET ANOTHER EDIT To make up for this I have created a very ugly event-driven workaround. The underlying event handler looks like the following : private void LvArticlesSelectionChanged(object sender, System.Windows.Controls. SelectionChangedEventArgs e) { ArticleViewModel avm = this.Articles.

SelectedItem as ArticleViewModel; foreach (CategoryViewModel cvm in this.ViewModel. Categories) { if( cvm. Equals( avm.

Category ) ) { this.cbCategories. SelectedItem = cvm; } } } This is the most ugly solution I can imagine - what do we have bindings for? But since I have to deliver, I'll go for this until somebody comes along with a great explanation... wpf data-binding xaml usercontrols link|improve this question edited Sep 9 '10 at 7:17 asked Sep 8 '10 at 8:31Sebastian Edelmeier915211 97% accept rate.

Two options: Option 1 change RelativeSource binding: Most simple solution: Change the DataSource thing to find your correct parent. DataContext="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type MyNamespace:IconButton}}}" Option 2 Template bindings: Rewrite your control, so that it uses a ControlTemplate, so you can use TemplateBindings on the properties you want to take over from your parent control: ...

Setting the DataContext in XAML was my second attempt. At first I used the IconButton's Constructor for that (this. DataContext = this).

Going back there is the easiest fix I can Imagine...but it doesn't change a thing. – Sebastian Edelmeier Sep 8 '10 at 8:55 Don't rely on the Visual Designer too much. It usually is the first thing to break in our projects.

If it works with compiled code in runtime, it is alright, not? :) – Arcturus Sep 8 '10 at 9:17 Yup, it's just an auxiliary tool anyway. BTW, thanks for your response!

I am afraid it won't take me very far,since it moves complexity to the template, but doesn't eliminate / explain my problem – Sebastian Edelmeier Sep 8 '10 at 9:48.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.