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How can I use data binding in WPF to create a new user control for each element in a list?

I have a list of objects. For each item in the list, I want to create a new user control bound to that item. From what I've read, doing this programmatically is bad practice with WPF (as well as less than straightforward), so I should use data binding as a solution instead. The problem is, I can't figure out how to do this. I don't know the contents of the list (just the type) at compile-time, so I can't create and bind with XAML for each element. Google and MSDN don't seem to have any answers, so maybe I'm thinking about this the wrong way? What do I need to do?

Thanks

EDIT: To clarify, I'm trying to make my own music scoring software, something like Rosegarden. The list would contain all of the measures, and the usercontrols would be their visual representation.

like image 329
Joel Avatar asked Dec 17 '22 00:12

Joel


2 Answers

A more generic approach than Julien Lebosquain's suggestion (and one that will work when the list of items contains objects of more than one data type):

Create a DataTemplate to be used in presenting an item of the type(s) in your list, e.g.:

<DataTemplate DataType="local:Measure">
   <local:MeasureUserControl DataContext="{Binding}"/>
</DataTemplate>

Use an ItemsControl to present the items:

<ItemsControl ItemsSource="{Binding MeasureList}"/>

You can set the ItemsPanel property of the ItemsControl to an ItemsPanelTemplate to govern how it will lay out the user controls, e.g.:

<ItemsControl.ItemsPanel>
   <ItemsPanelTemplate>
      <StackPanel Orientation="Horizontal"/>
   </ItemsPanelTemplate>
</ItemsControl.ItemsPanel>

This approach is generally preferable to using a ListBox when you don't want the features of the ListBox, e.g. its default border and selection behavior.

like image 186
Robert Rossney Avatar answered Dec 24 '22 02:12

Robert Rossney


You can use a standard ListBox with a custom item style:

Somewhere in the resources:

<Style TargetType="{x:Type ListBoxItem}" x:Key="CustomItemStyle">
  <Setter Property="Template">
    <Setter.Value>
      <ControlTemplate TargetType="{x:Type ListBoxItem}">
        <yourns:YourControl />
      </ControlTemplate>
    </Setter.Value>
  </Setter>
</Style>

In your window/page/usercontrol:

<ListBox ItemsSource="{Binding ...}" ItemContainerStyle="{StaticResource CustomItemStyle}" />

Since your objects will be bound to the listbox, an implicit ListBoxItem will be created for each object, with its DataContext set to the object so you can use bindings in YourControl without any worries.

like image 33
Julien Lebosquain Avatar answered Dec 24 '22 01:12

Julien Lebosquain