According to all of the documentation, when you're creating a non-lookless control, you're supposed to subclass UserControl. However, UserControl is a simple subclass of ContentControl but it doesn't appear to add anything to it, interface-wise. As such, you can take that designer-generated code and change the base class to ContentControl and it appears to still work exactly the same.
So what's the point of UserControl over ContentControl?
Update:
For those who keep answering Visual Studio treats them differently, I'd argue that isn't the case. Try it! Create a new UserControl in Visual Studio, then in the resulting XAML file, change the root tag to ContentControl. Then in the associated class file, change the base class to ContentControl or simply delete it as I have done here (see the note) and you'll see it appears to work exactly the same, including full WYSIWYG designer support.
Note: You can delete the base class from the code-behind because it's actually a partial class with the other 'part' of the class being created by the XAML designer via code-generation. As such, the base class will always be defined as the root element of the XAML file, so you can simply omit it in the code-behind as it's redundant.
Here's the updated XAML...
<ContentControl x:Class="Playground.ComboTest.InlineTextEditor"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<TextBlock Text="Success" />
</ContentControl>
...and the associated class file...
namespace Playground.ComboTest {
public partial class InlineTextEditor {
public InlineTextEditor()
=> InitializeComponent();
}
}
ContentControlis thatUserControloverrides theOnCreateAutomationPeermethod, you might look for that. Maybe it has some different UI-behaviors than the ContentControl. – Drumhead