Nullability in Microsoft.Maui.Controls

[cleardemon]

Using nullability support in modern C# is pretty common, however, there seems to be plenty of occurrences where, in MAUI, nullability is simply not supported.

An example is when using Shell.Current, while unlikely (but still possible, given a recent crash on Android in production), this property can actually return null.

Drilling down, Shell.Current is a wrapper for Application.Current. But Shell.Current is not declared as possibly returning null, in fact, in the Shell.cs file, #nullable disable is right at the top.

It's not just this. There are other places where things can be null in MAUI, and they are just not declared as being so in the API. When using nullable throughout one's project, this does not provide the benefit of being able to spot when properties can be null, potentially leading to unchecked null references.

Obviously, you can still check if a property is null. But, with #nullable enable, if you check a property like InputView.Text - which does not declare itself as nullable, either, despite saying it defaults to null in the documentation - you get a warning saying Text can't be null.

Is there a plan to support nullability properly in MAUI? It seems patchy (e.g. Application.Current is nullable), and it seems like there is room for improvement, but it also seems like a rather large task to do.

[MartyIX]

There are PRs that improve the status quo:

• [Net 10] - Annotated remaining Converter classes for nullability - 2 #30777
• Annotated remaining Converter classes for nullability #30573
• Apply nullability attributes to TimeChangedEventArgs type as well #29513

Drilling down, Shell.Current is a wrapper for Application.Current. But Shell.Current is not declared as possibly returning null, in fact, in the Shell.cs file, #nullable disable is right at the top.

This would be a nice community PR to target the net10.0 git branch. :)

Is there a plan to support nullability properly in MAUI? It seems patchy (e.g. Application.Current is nullable), and it seems like there is room for improvement, but it also seems like a rather large task to do.

There is #12600. But yes, it's a lot of work. However, one can slowly improve it.