Proposal: Instantiate Resources from Dependency Injection

Proposal: Instantiate Resources from Dependency Injection

Summary

Use Microsoft.Extensions.DependencyInjection or other framework that implements IServiceProvider to instantiate resources to instantiate Resources from XAML…

Rationale

• Dependency Injection allows for creating loosely coupled resources such as View Models that are defined in separate or distant (not in same solution) projects.
• Current methods require requiring a “dummy instance” on a default constructor that can be instantiated by Xaml, and then removing and replacing it at runtime from the Resources.
• Will greatly improve maintainability and quality of code.

Scope

Capability	Priority
This proposal will allow developers to use design time bindings on View Models and other objects created via Dependency Injection	Must
This proposal will allow developers to use any dependency injection framework that implements IServiceProvider.	Must
This proposal will allow developers to define an Interface as a Resource since the instance will be obtained from the IServiceProvider.	Must
This proposal will not require dependency injection for all projects.	Must

Important Notes

Example

<local:IMyResource x:Key="MyResource" ServiceProvider="{x:Bind Provider}" />

Here, ServiceProvider is any instance of IServiceProvider that can be resolved via x:Bind.

[sharpninja]

Nice, do you have a simple skeleton to share by any chance?

https://github.com/sharpninja/WindowsAppSdkHost

[jesbis]

Thanks for the full example! That’s much clearer.

This seems worth considering. It’s unlikely we’ll be able to get to this for the first WinUI 3.0 release, so we’ll keep it in the backlog for a future iteration.