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xamarin.iosuwpxamarin.formsportable-class-library

Density of screen in iOS and Universal WIndows App

Hi I need to know the density of screen in windows 10/8/8.1 and iOS. I got screen density in Android using DisplayMetrics but I find no such option/property available in UWP and iOS. So Is there any property through which I can get screen density in UWP and IOS.

Solution

  • UPDATE - June 8th 2018

    Xamarin has released Xamarin.Essentials!

    Xamarin.Essentials provides developers with cross-platform APIs for their mobile applications.

    Android, iOS, and UWP offer unique operating system and platform APIs that developers have access to all in C# leveraging Xamarin. Xamarin.Essentials provides a single cross-platform API that works with any Xamarin.Forms, Android, iOS, or UWP application that can be accessed from shared code no matter how the user interface is created. https://github.com/xamarin/Essentials

    You can now query the device's display information without having to manage all of the individual platform code pieces.

    Device Display Information - https://learn.microsoft.com/en-us/xamarin/essentials/device-display

    How-To:

    Add a reference to Xamarin.Essentials in your class:

    using Xamarin.Essentials;

    The following information is exposed through the API:

    // Get Metrics
var mainDisplayInfo = DeviceDisplay.MainDisplayInfo;

// Orientation (Landscape, Portrait, Square, Unknown)
var orientation = mainDisplayInfo.Orientation;

// Rotation (0, 90, 180, 270)
var rotation = mainDisplayInfo.Rotation;

// Width (in pixels)
var width = mainDisplayInfo.Width;

// Height (in pixels)
var height = mainDisplayInfo.Height;

// Screen density
var density = mainDisplayInfo.Density;

    Useful Links:

    Original Post (Before Xamarin.Essentials existed)

    Below, I'm storing the specific OS's screen details in static vars, located in the Xamarin Forms App class

    These all appear to work in my testing.

    (copy/pasted from my github page - https://github.com/mattregul/Xamarin_Screensize)

    Android (MainActivity.cs) - Jump to Github Page

    // Store off the device sizes, so we can access them within Xamarin Forms
// Screen Width = WidthPixels / Density
// Screen Height = HeightPixels / Density

App.DisplayScreenWidth  = (double)Resources.DisplayMetrics.WidthPixels / (double)Resources.DisplayMetrics.Density;
App.DisplayScreenHeight = (double)Resources.DisplayMetrics.HeightPixels / (double)Resources.DisplayMetrics.Density; 
App.DisplayScaleFactor  = (double)Resources.DisplayMetrics.Density;

    iOS (AppDelegate.cs) - Jump to Github Page

    // Store off the device sizes, so we can access them within Xamarin Forms
App.DisplayScreenWidth  = (double)UIScreen.MainScreen.Bounds.Width;
App.DisplayScreenHeight = (double)UIScreen.MainScreen.Bounds.Height;
App.DisplayScaleFactor  = (double)UIScreen.MainScreen.Scale;

    Note In all Windows examples screensize is the root project namespace

    UWP (App.xaml.cs) - Jump to Github Page

    // You decided which is best for you...
//  Do you want Size of the App's View
//      or
//  Do you want the Display's resolution 
// ######################################

// Size of App's view
screensize.App.DisplayScreenHeight = Windows.UI.ViewManagement.ApplicationView.GetForCurrentView().VisibleBounds.Height;
screensize.App.DisplayScreenWidth = Windows.UI.ViewManagement.ApplicationView.GetForCurrentView().VisibleBounds.Width;

// Size of screen's resolution
//screensize.App.DisplayScreenWidth = Windows.Graphics.Display.DisplayInformation.GetForCurrentView().ScreenHeightInRawPixels;
//screensize.App.DisplayScreenHeight = Windows.Graphics.Display.DisplayInformation.GetForCurrentView().ScreenWidthInRawPixels;

// Pixels per View Pixel
// - https://msdn.microsoft.com/en-us/windows/uwp/layout/design-and-ui-intro#effective-pixels-and-scaling
// - https://msdn.microsoft.com/en-us/windows/uwp/layout/screen-sizes-and-breakpoints-for-responsive-design
screensize.App.DisplayScaleFactor = Windows.Graphics.Display.DisplayInformation.GetForCurrentView().RawPixelsPerViewPixel;

    Windows Phone 8.1 (App.xaml.cs) - Jump to Github Page

    // Size of App's view
screensize.App.DisplayScreenHeight = Windows.UI.ViewManagement.ApplicationView.GetForCurrentView().VisibleBounds.Height;
screensize.App.DisplayScreenWidth = Windows.UI.ViewManagement.ApplicationView.GetForCurrentView().VisibleBounds.Width;

// Pixels per View Pixel
// - https://msdn.microsoft.com/en-us/windows/uwp/layout/design-and-ui-intro#effective-pixels-and-scaling
// - https://msdn.microsoft.com/en-us/windows/uwp/layout/screen-sizes-and-breakpoints-for-responsive-design
screensize.App.DisplayScaleFactor = Windows.Graphics.Display.DisplayInformation.GetForCurrentView().RawPixelsPerViewPixel;

    Windows 8.1 (App.xaml.cs) - Jump to Github Page

    // Size of App's view
screensize.App.DisplayScreenHeight = Window.Current.Bounds.Height;
screensize.App.DisplayScreenWidth = Window.Current.Bounds.Width;
screensize.App.DisplayScaleFactor = 1; // No scaling here?  If you find a scaling for Windows 8.1, please let me know :)

    Xamarin Forms Page (App.cs) - Jump to Github Page

    namespace screensize
{
    public class App : Application
    {
        public static double DisplayScreenWidth = 0f;
        public static double DisplayScreenHeight = 0f;
        public static double DisplayScaleFactor = 0f;

        public App()
        {

            string ScreenDetails = Device.OS.ToString() + " Device Screen Size:\n" +
                $"Width: {DisplayScreenWidth}\n" +
                $"Height: {DisplayScreenHeight}\n" +
                $"Scale Factor: {DisplayScaleFactor}";

            // The root page of your application
            var content = new ContentPage
            {
                Title = "Xamarin_GetDeviceScreensize",
                Content = new StackLayout
                {
                    VerticalOptions = LayoutOptions.Center,
                    Children = {
                        new Label {
                            HorizontalTextAlignment = TextAlignment.Center,
                            FontSize = Device.GetNamedSize (NamedSize.Large, typeof(Label)),
                            Text = ScreenDetails
                        }
                    }
                }
            };

            MainPage = new NavigationPage(content);
        }

    }
}