Xamarin Forms Platform-specific Setbarselecteditemcolor Has No Effect

I want to change the color of the active tab indictor dynamically. Multiple sources (Xamarin support, Xamarin docs) suggest there is a method that does just this, but it has to be

Solution 1:

From official document , you can set static color for BarSelectedItem as follow:

<TabbedPage...xmlns:android="clr-namespace:Xamarin.Forms.PlatformConfiguration.AndroidSpecific;assembly=Xamarin.Forms.Core"android:TabbedPage.ToolbarPlacement="Bottom"android:TabbedPage.BarItemColor="Black"android:TabbedPage.BarSelectedItemColor="Red">
    ...
</TabbedPage>

Answer :

By using DynamicResource,it can set BarSelectedItemColor dynamically:

android:TabbedPage.BarSelectedItemColor="Red"

To this:

android:TabbedPage.BarSelectedItemColor="{DynamicResource BarSelectedItemColor}"

Complete sample code:

<TabbedPagexmlns="http://xamarin.com/schemas/2014/forms"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:local="clr-namespace:TabbedPageDemo;assembly=TabbedPageDemo"x:Class="TabbedPageDemo.TabbedPageDemoPage"xmlns:android="clr-namespace:Xamarin.Forms.PlatformConfiguration.AndroidSpecific;assembly=Xamarin.Forms.Core"android:TabbedPage.ToolbarPlacement="Bottom"android:TabbedPage.BarItemColor="Black"android:TabbedPage.BarSelectedItemColor="{DynamicResource BarSelectedItemColor}"><TabbedPage.Resources><ResourceDictionary><Colorx:Key="BlueColor">Blue</Color><Colorx:Key="YellowColor">Yellow</Color></ResourceDictionary></TabbedPage.Resources>
  ...
</TabbedPage>

Where you want to change color can be set in ContentPage as follow:

 Resources["BarSelectedItemColor"] = Resources["BlueColor"];
 ...
 Resources["BarSelectedItemColor"] = Resources["YellowColor"];

If you do not need use this renderer,you should comment its reference. My Forms answer code will work.

//[assembly: ExportRenderer(typeof(TabbedPage), typeof(TabRenderer))]

And should remove this property in Xaml:

<TabbedPage.BarTextColor><OnPlatformx:TypeArguments="Color"><OnPlatform="Android"Value="Green" /></OnPlatform></TabbedPage.BarTextColor>