How to change application icon in Xamarin.Forms?

Updating Icon and Name (Android)

If you changed the icon file name please ensure you update the Icon reference in MainActivity.cs:

[Activity(Label = "MyName", Icon = "@mipmap/myicon", Theme = "@style/MainTheme"]    
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{ 
}

You should also update the names of icon.xml and icon_round.xml in the mipmap-anydpi folder to match to new icon name. If launcher-foreground.png was renamed then update the value of <foreground...> in corresponding icon.xml.

Summary (Android)

1. Replace the png's in mipmap folders with your new icon
2. If name was changed, update Icon value in MainActivity.cs
3. If name was changed, update name of (or create a new copy of) icon.xml and icon_round.xml
4. If name of launcher-foreground.png was changed then update value in icon.xml. Eg:

   <adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
     <background android:drawable="@color/my_launcher_background"/>
     <foreground android:drawable="@mipmap/my_launcher_foreground"/>
   </adaptive-icon>
   

5. If name wasn't changed and you've cleaned and re-built project but still your new icons are not deploying: Delete obj folder from Android project directory

Details and Issues if not updating (Android)

Xamarin Forms/Android puts 2 icons in each mipmap folder (mipmap-mdpi, mipmap-hdpi, mipmap-xhdpi, etc) - icon.png and launcher-foreground.png.

Replace both these images in each of the mipmap folders. I kept the same names but it should be possible to use a different name.

If you rename launcher-foreground.png then you must update the values in icon.xml and icon_round.xml (or their equivalent new names). The value in the <foreground...> tag references the icon/png. So, if launcher-foreground.png was updated to my_launcher-foreground.png this should be reflected in the icon.xml (see step 4 in summary above).

If the icons still don't update even after cleaning/re-building it could be that the original/default icons still existed in the Android project obj folder. The solution is to delete the obj folder from the Android project directory.

iOS

For iOS, please see Managing Icons with Asset Catalogs. A summary taken from the linked page is provided below:

For icons, a special AppIcon image set can be added to the Assets.xcassets file in the app's project.

To use an Asset Catalog, do the following:

1. Double-click the Info.plist file in the Solution Explorer.
2. Click on the Visual Assets tab and click on the Use Asset Catalog button under App Icons.
3. From the Solution Explorer, expand the Asset Catalog folder.
4. Double-click the Media file to open it in the editor.
5. Under the Properties Explorer the developer can select the different types and sizes of icons required.
6. Click on given icon type and select an image file for the required type/size.
7. Click the Open button to include the image in the project and set it in the xcasset.

MacOs

The guide for MacOs is Application icon for Xamarin.Mac apps. You need to consider the following steps:

1. Required image sizes and filenames
2. Packaging the icon resources
3. Using the icon

detailed in the linked docs above.

For Android try to set the icon app like this:

[Activity(Icon = "@drawable/icon")]
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsApplicationActivity
{
     .....
}

Make sure that you have changed all the icon images on all drawable folders ( drawable, drawable-hdpi, drawable-xhdpi and drawable-xxhdpi ).

For iOS I like set the app icons and splash screen with Asset Catalogs, here you can find a guide to how to use it:

https://developer.xamarin.com/guides/ios/application_fundamentals/working_with_images/app-icons/

For iOS in visual studio...

Step1: Generate all the app icons from https://appicon.co/

Step2: In solution explorer, under iOS project, expand 'Asset Catalogs' and double click on 'Assests'. You can change the existing 'AppIcon' icons or Add a new Asset and attach the icons.

This is how you add a new asset...

Step3: In solution explorer, under iOS project, double click on Info.plist. Go to 'Visual Assets' tab, click on 'App Icons' and change the 'Source' to the asset that you just created.

Done.

Hope this helps someone!