The BindingContext of the Window TitleBar is not being passed on to its child content.

[egvijayanand]

Description

Passing the BindingContext value to the child content of Window TitleBar is essential, as it facilitates the binding of properties and commands of the controls hosted within it to a ViewModel instance.

Public API Changes

Propagate the BindingContext value to all the child content of Window TitleBar and inherit its value from the Window's BindingContext.

Intended Use-Case

To manage the properties and commands of the controls hosted within the Window TitleBar from the ViewModel.

[egvijayanand]

I'm trying to bind the SearchBar, hosted in the TitleBar, to a property and command in the ViewModel.

[Foda]

Hello! The TitleBar in .NET 9 of MAUI supports this. You can see an example of the BindingContext (and the Window titlebar) being set here:
https://github.com/dotnet/maui/blob/net9.0/src/Controls/samples/Controls.Sample/Pages/PlatformSpecifics/Windows/WindowsTileBarPage.xaml.cs#L21C1-L38C4

[egvijayanand]

Still the BindingContext is set separately for the TitleBar. Is that the recommended approach?

I've defined the TitleBar in XAML as part of the Window definition. I'm assigning the Window BindingContext, which is not passed on to the TitleBar. The child control is supposed to inherit the parent's BindingContext.

Will upload and share the sample by tomorrow.

[egvijayanand]

I have pushed a sample project on GitHub here.

The issue is the BindingContext passed to the TitleBar is not propagated to the LeadingContent, Content, and TrailingContent.

• Build the app and launch it, then click on the Gear icon on the TitleBar; the associated command is not invoked
• Now go to the code-behind file of the MainWindow and uncomment the line in the constructor
• Once again build and run the app, then click on the Gear icon on the TitleBar

[michael-b-tt0]

The issue is the BindingContext passed to the TitleBar is not propagated to the LeadingContent, Content, and TrailingContent.

I have this exact issue at the moment but you can work around it by directly setting the BindingContext on a control by control basis

[AndreasReitberger]

Also seeing this issue in the latest version of maui. Any ETA for a fix?