C#•7mo ago

✅ how do you properly handle a "Possible null reference return"?

i've got a property on my class that looks like so

private ViewModelBase? _CurrentPage;
...
public ViewModelBase CurrentPage
{
    get { return _CurrentPage; }
    set { this.RaiseAndSetIfChanged(ref _CurrentPage, value); }
}

private ViewModelBase? _CurrentPage;
...
public ViewModelBase CurrentPage
{
    get { return _CurrentPage; }
    set { this.RaiseAndSetIfChanged(ref _CurrentPage, value); }
}

private ViewModelBase? _CurrentPage;
...
public ViewModelBase CurrentPage
{
    get { return _CurrentPage; }
    set { this.RaiseAndSetIfChanged(ref _CurrentPage, value); }
}

private ViewModelBase? _CurrentPage;
...
public ViewModelBase CurrentPage
{
    get { return _CurrentPage; }
    set { this.RaiseAndSetIfChanged(ref _CurrentPage, value); }
}

vs is giving me a green squiggly in the

get {}

get {}

get {}

get {} block saying the value might be null. The program itself compiles and runs but just out of curiosity how do you properly resolve the warning?

Eenrico11011 i've got a property on my class that looks like so ```csharp private ViewModelB...

jcotton42•6/4/25, 5:39 AM

_CurrentPage_CurrentPage (which really should be spelled _currentPage_currentPage fwiw) is declared as nullable, but CurrentPageCurrentPage isn't

enrico11011OP•6/4/25, 5:40 AM

is underscore + lowercase starting letter the generally accepted convention for private backing fields?

jcotton42•6/4/25, 5:40 AM

underscore is personal preference, but yes, they should be camelCase, not PascalCase

enrico11011OP•6/4/25, 5:42 AM

got it. both have to be nullable and prefer camelCase

enrico11011OP•6/4/25, 5:42 AM

thanks

jcotton42•6/4/25, 5:43 AM

also, consider using something like the mvvm toolkit to handle much of the drudgery for you https://learn.microsoft.com/en-us/dotnet/communitytoolkit/mvvm/

Introduction to the MVVM Toolkit - Community Toolkits for .NET

An overview of how to get started with the MVVM Toolkit and to the APIs it contains

jcotton42•6/4/25, 5:43 AM

https://learn.microsoft.com/en-us/dotnet/communitytoolkit/mvvm/generators/overview

MVVM source generators - Community Toolkits for .NET

An overview of Roslyn source generators to power MVVM scenarios

Eenrico11011 got it. both have to be nullable and prefer camelCase

ero•6/4/25, 5:45 AM

do they? i would think neither should be nullable?

enrico11011OP•6/4/25, 5:51 AM

now that I think about it yeah probably. idk this is my first time with avalonia and i've only been doing C# for, like, a month now

jcotton42•6/4/25, 5:52 AM

I would use the MVVM toolkit, it will save you a lot of boilerplate.

enrico11011OP•6/4/25, 5:55 AM

so they say, but I've only just gotten the hang of MVVM with reactive

enrico11011OP•6/4/25, 5:55 AM

i'll keep it in mind though, thanks

enrico11011OP•6/4/25, 5:56 AM

doesn't help that a lot of the reading material on either framework does nothing to introduce you to the pattern

✅ how do you properly handle a "Possible null reference return"?

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