Addressing warnings from CompiledBindings on .NET 9 on TemplateBinding

[MichaelLHerman]

Type of issue

Missing information

Description

After upgrading to .NET 9, I am seeing XC0022 warnings on my TemplateBindings. Documentation for neither Control Templates nor Compiled Bindings have been updated to provide information on what to do. Specify the data type on the ControlTemplate, or is there a plan for the Xaml Compiler to be able to automatically infer the data type in the future if the control template is a ControlTemplate of a particular ContentView? Samples need to be updated as well dotnet/maui-samples#547 (comment)

https://learn.microsoft.com/en-us/dotnet/maui/fundamentals/controltemplate?view=net-maui-9.0
https://learn.microsoft.com/en-us/dotnet/maui/fundamentals/data-binding/compiled-bindings?view=net-maui-9.0#compiled-bindings-in-xaml

Page URL

https://learn.microsoft.com/en-us/dotnet/maui/fundamentals/data-binding/compiled-bindings?view=net-maui-9.0

Content source URL

https://github.com/dotnet/docs-maui/blob/main/docs/fundamentals/data-binding/compiled-bindings.md

Document Version Independent Id

d8079bc8-3987-9069-717e-c5cbf3512ae1

Article author

@davidbritch

Metadata

• ID: d8079bc8-3987-9069-717e-c5cbf3512ae1
• Service: dotnet-mobile
• Sub-service: dotnet-maui

Related Issues

[davidbritch]

Hi @MichaelLHerman

I'll be looking at this tomorrow, but in the meantime https://learn.microsoft.com/en-us/dotnet/maui/fundamentals/data-binding/compiled-bindings?view=net-maui-9.0#xaml-compiled-bindings-warnings may help.

[MichaelLHerman]

@davidbritch Looks like specifying x:DataType in the control template is all that needs to be done (though this should be documented somewhere). In the ControlTemplateDemos sample, I added the data type and the warnings went away.

<ControlTemplate x:Key="CardViewControlTemplate" x:DataType="controls:CardView">

[jfversluis]

Those changes are now in the samples as per this PR: dotnet/maui-samples#552

Does that help you any further?