New Xamarin.Forms Guide: Custom Renderers

Xamarin.Forms user interfaces are rendered using the native controls of the target platform, allowing Xamarin.Forms applications to retain the appropriate look and feel for each platform. Custom Renderers let developers override this process to customize the appearance and behavior of Xamarin.Forms controls on each platform.

A new guide on creating custom renderers has recently been published. The guide describes the motivation for custom renderers, the base classes and native controls used for renderers, and custom renderers for specific controls.

Over time the guide will be expanded to cover additional custom renderers.

Exploring the guide

The guide includes the following topics:

• Introduction to Custom renderers

  Custom renderers provide a powerful approach for customizing the appearance and behavior of Xamarin.Forms controls. They can be used for small styling changes or sophisticated platform-specific layout and behavior customization. This article provides an introduction to custom renderers, and outlines the process for creating a custom renderer.

• Renderer Base Classes and Native Controls

  Every Xamarin.Forms control has an accompanying renderer for each platform that creates an instance of a native control. This article lists the renderer and native control classes that implement each Xamarin.Forms page, layout, view, and cell.

• Customizing an Entry

  The Xamarin.Forms Entry control allows a single line of text to be edited. This article demonstrates how to create a custom renderer for the Entry control, enabling developers to override the default native rendering with their own platform-specific customization.

• Customizing a ContentPage

  A ContentPage is a visual element that displays a single view and occupies most of the screen. This article demonstrates how to create a custom renderer for the ContentPage page, enabling developers to override the default native rendering with their own platform-specific customization.

• Customizing a ListView

  A Xamarin.Forms ListView is a view that displays a collection of data as a vertical list. This article demonstrates how to create a custom renderer that encapsulates platform-specific list controls and native cell layouts, allowing more control over native list control performance.

• Customizing a ViewCell

  A Xamarin.Forms ViewCell is a cell that can be added to a ListView or TableView, which contains a developer-defined view. This article demonstrates how to create a custom renderer for a ViewCell that's hosted inside a Xamarin.Forms ListView control. This stops the Xamarin.Forms layout calculations from being repeatedly called during ListView scrolling.

Exploring the samples

Along with the guide there are also sample apps that demonstrate the concepts explained in the guide:

• Entry Custom Renderer

  This sample demonstrates a custom renderer for the Entry control, enabling developers to override the default native rendering with their own platform-specific customization.

• ContentPage Custom Renderer

  This sample demonstrates a custom renderer for a ContentPage, enabling developers to override the default native rendering with their own platform-specific customization.

• ListView Custom Renderer

  This sample demonstrates a custom renderer that encapsulates platform-specific list controls and native cell layouts.

• ViewCell Custom Renderer
  This sample demonstrates a custom renderer for a ViewCell that's hosted inside a Xamarin.Forms ListView control, enabling developers to override the default native rendering with their own platform-specific customization.