Xamarin.Forms : change dynamically BarBackgroundColor

Question

In a Xamarin.Forms program, how to dynamically change the BarBackgroundColor? I already changed the app.xaml file like this:

<Application.Resources>
    <ResourceDictionary>
        <!--Global Styles-->
        <Color x:Key="NavigationPrimary">#2196F3</Color>
        <Style TargetType="NavigationPage">
            <Setter Property="BarBackgroundColor" Value="DarkOliveGreen" />
            <Setter Property="BarTextColor" Value="White" />
        </Style>
    </ResourceDictionary>
</Application.Resources>

But the color changes are not dynamic: they are read when the app is started, then can no longer be modified.

This works by making the following changes in the app.xaml.cs file:

            DB_ParametreList = dbparametre.GetAllParametre();
            parametres = DB_ParametreList[0];
            if (parametres.WallpaperName == "wallpapers_4.png")
            {
                MainPage = new NavigationPage(new ListeAchatsPage())
                {
                    BarBackgroundColor = Color.FromHex("#705502"),
                    BarTextColor = Color.White,
                };
            }
            else if (parametres.WallpaperName == "wallpapers_3.png")
            {
                MainPage = new NavigationPage(new ListeAchatsPage())
                {
                    BarBackgroundColor = Color.FromHex("#09506B"),
                    BarTextColor = Color.White,
                };
            }
            else
            {
                MainPage = new NavigationPage(new ListeAchatsPage())
                {
                    BarBackgroundColor = Color.DarkOliveGreen,
                    BarTextColor = Color.White,
                };
            }

The problem comes from the MainPage which cannot be a NavigationPage because I have to display the icon of a Hambuger menu. Please help me to resolve this issue.

Answer 1

Hello,

Xamarin support has been ended, please upgrade Xamarin projects to .NE.

See Upgrade from Xamarin to .NET & .NET MAUI

Xamarin official support policy | .NET (microsoft.com)

Best Regards,

Wenyan Zhang

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