MVVM Toolkit info MVVMTK0056

Semi-auto properties should be converted to partial properties using [ObservableProperty] when possible, which is recommended (doing so makes the code less verbose and results in more optimized code).

The following sample generates MVVMTK0056:

<PropertyGroup>
    <LangVersion>preview</LangVersion>
</PropertyGroup>

using CommunityToolkit.Mvvm.ComponentModel;

namespace MyApp;

public partial class SampleViewModel : ObservableObject
{
    public string? Name
    {
        get;
        set => SetProperty(ref field, value);
    }
}

You can fix this by converting the property to use [ObservableProperty] instead:

using CommunityToolkit.Mvvm.ComponentModel;

namespace MyApp;

public partial class SampleViewModel : ObservableObject
{
    [ObservableProperty]
    public partial string? Name { get; set; }
}

There is also a built-in code fixer for this diagnostic, to easily fix all occurrences in a single click.

Additional resources

• You can find more examples in the unit tests.