General guidance for making WinUI/UWP-only code Uno compatible

This article explains adjustments that may need to be made to WinUI/UWP-only code for it to run on Uno Platform, be it in an application or a class library.

Code adjustments

Add 'partial' to some class definitions

Certain class definitions will need to have the partial keyword added, so that Uno's source generators can add code to them at compile time.

You'll need to do this for:

• types backed by a XAML file, which the XAML generator completes
• types declaring a [GeneratedDependencyProperty]

Note

Inheriting directly from DependencyObject no longer requires partial. Before Uno Platform 7.0, DependencyObject was an interface whose implementation a source generator supplied; it is now an ordinary class. See DependencyObject is a class.

Apart from adding partial, you don't need to worry about the generated code. You may however get misleading errors from Intellisense until the first time you try to compile the project, because the generated partial classes haven't been added yet.

Note

Since Uno Platform 7.0 the UI is rendered with Skia on every target, and FrameworkElement no longer inherits a native Android or iOS view type. Earlier guidance about name collisions with native view members (such as UIView.Window or View.TextAlignment), and about nesting FrameworkElement-derived classes on iOS, no longer applies. To host a native view alongside Uno content, see Incorporating native views.

Adjust for unsupported runtime features

Not all .NET runtime features are supported on every platform. See Migrating - Before You Start for more details.