Register the RadChart renderer
When certain features are available in the native control on a given platform, but not exposed in Xamarin.Forms you would need to create a custom renderer. This will allow you to access the native control and configure it as per your needs.
This article will guide you how to register custom renderer for RadChart control.
You will need to create a class for each platform and register your custom renderer using the ExportRenderer assembly level attribute.
GradientBars example demonstrates how to create custom renderer for each platform and it can be found in the Chart/Customization folder of the SDK Samples Browser application.
Android Project
Register custom renderer for CartesianChart.
[assembly: ExportRenderer(typeof(Telerik.XamarinForms.Chart.RadCartesianChart), typeof(Telerik.XamarinForms.ChartRenderer.Android.CartesianChartRenderer))]
Register custom renderer for PieChart
[assembly: ExportRenderer(typeof(Telerik.XamarinForms.Chart.RadPieChart), typeof(Telerik.XamarinForms.ChartRenderer.Android.PieChartRenderer))]
See the native Android RadChartView documentation for more information.
iOS Project
Register custom renderer for CartesianChart
[assembly: ExportRenderer(typeof(Telerik.XamarinForms.Chart.RadCartesianChart), typeof(Telerik.XamarinForms.ChartRenderer.iOS.CartesianChartRenderer))]
Register custom renderer for PieChart
[assembly: ExportRenderer(typeof(Telerik.XamarinForms.Chart.RadPieChart), typeof(Telerik.XamarinForms.ChartRenderer.iOS.PieChartRenderer))]
See the native iOS TKChart documentation for more information.
UWP Projects
Register custom renderer for CartesianChart
[assembly: Xamarin.Forms.Platform.UWP.ExportRenderer(typeof(Telerik.XamarinForms.Chart.RadCartesianChart), typeof(Telerik.XamarinForms.ChartRenderer.UWP.CartesianChartRenderer))]
Register custom renderer for PieChart
[assembly: Xamarin.Forms.Platform.UWP.ExportRenderer(typeof(Telerik.XamarinForms.Chart.RadPieChart), typeof(Telerik.XamarinForms.ChartRenderer.UWP.PieChartRenderer))]
See the native UWP RadChart documentation for more information.