Net Maui - The type or namespace name 'App' could not be found-CodePudding

I am using .NET Maui and suddenly got an error with the error code CS0246 in the File MauiProgram.cs. The code of the file is:

public static class MauiProgram
{
    public static MauiApp CreateMauiApp()
    {
        var builder = MauiApp.CreateBuilder();
        Builder
            . UseMauiApp<App>()
            . ConfigureFonts(fonts =>
            {
                Fonts. AddFont("OpenSans-Regular.ttf", "OpenSansRegular");
                Fonts. AddFont("OpenSans Semibold.ttf", "OpenSansSemibold");
            });

return builder. Build();
    }
}

The error is displayed as following:

Severity Code Description Project File Line Suppression State Error CS0246 The type or namespace name 'App' could not be found (are you missing a using directive or an assembly reference?) itsl (net6.0-maccatalyst), itsl (net6.0-windows10.0.22621.0) A:\VS\itsl\itsl\MauiProgram.cs 9 Active

I've already cleaned up the solution and restarted Visual Studio, but unfortunately nothing helped.

What can I do?

CodePudding user response：

App is the class defined in App.xaml. By default it should be in the same namespace as MauiProgram, but if you have manually changed a namespace you may need to add a using statement