将阴影添加到标签- Xamarin.Forms

using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;

[assembly: ExportRenderer(typeof(Label), typeof(CustomLabelRenderer))]
namespace YourNamespace.iOS
{
    public class CustomLabelRenderer : LabelRenderer
    {
        protected override void OnElementChanged(ElementChangedEventArgs<Label> e)
        {
            base.OnElementChanged(e);

            if (Control != null)
            {
                Control.Layer.ShadowColor = UIColor.Black.CGColor;
                Control.Layer.ShadowOffset = new CoreGraphics.CGSize(5, 5);
                Control.Layer.ShadowOpacity = 0.5f;
                Control.Layer.ShadowRadius = 5;
                Control.Layer.MasksToBounds = false;
            }
        }
    }
}

using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;

[assembly: ExportRenderer(typeof(Label), typeof(CustomLabelRenderer))]
namespace YourNamespace.Droid
{
    public class CustomLabelRenderer : LabelRenderer
    {
        protected override void OnElementChanged(ElementChangedEventArgs<Label> e)
        {
            base.OnElementChanged(e);

            if (Control != null)
            {
                Control.Elevation = 10;
                Control.TranslationZ = 10;
            }
        }
    }
}

using Xamarin.Forms;
using Xamarin.Forms.Platform.UWP;
using Windows.UI.Xaml.Media;

[assembly: ExportRenderer(typeof(Label), typeof(CustomLabelRenderer))]
namespace YourNamespace.UWP
{
    public class CustomLabelRenderer : LabelRenderer
    {
        protected override void OnElementChanged(ElementChangedEventArgs<Label> e)
        {
            base.OnElementChanged(e);

            if (Control != null)
            {
                var dropShadowPanel = new Windows.UI.Xaml.Controls.DropShadowPanel();
                dropShadowPanel.ShadowOpacity = 0.5;
                dropShadowPanel.ShadowColor = Windows.UI.Colors.Black;
                dropShadowPanel.ShadowOffset = new Windows.Foundation.Point(5, 5);
                dropShadowPanel.Content = Control;

                SetNativeControl(dropShadowPanel);
            }
        }
    }
}