> For the complete documentation index, see [llms.txt](https://docs.apryse.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.apryse.com/xamarin/get-started/xamarin-android/customize-android.md).

# Step 3: Customize Xamarin.Android document viewer

Learn how to customize a document viewer in Xamarin.Android with Apryse. Customize appearance, functionality, annotations, and more using open-source tools. Click to optimize your app now! The Apryse

{% hint style="info" %}
\*\*This tutorial only applies to Xamarin.Android. See Xamarin.iOS equivalent here. \*\*
{% endhint %}

After you have [added Apryse to your project](/xamarin/get-started/xamarin-android/integrate-android.md) and [added a document viewer](/xamarin/get-started/xamarin-android/view-android.md), learn how to customize it for your app.

## Customize a document viewer

Apryse includes [DocumentActivity](/xamarin/guides/android/basics/open.md#activity) and [PdfViewCtrlTabHostFragment2](/xamarin/guides/android/basics/open.md#fragment) for showing documents. To customize their appearance and function, see [**Customizing a document viewer**](/xamarin/viewer/viewer-config.md#android).

Apryse also includes a low-level `ViewGroup` ([PDFViewCtrl](/xamarin/guides/android/basics/open.md#view)) to show documents. If you are using it, please see [**Customizing a PDFViewCtrl**](/xamarin/viewer/custom-viewer.md#android).

## Customize individual components

Apryse includes a rich set of controls. They are used by the [DocumentActivity](/xamarin/guides/android/basics/open.md#activity) and [PdfViewCtrlTabHostFragment2](/xamarin/guides/android/basics/open.md#fragment), and can also be used independently. To learn more about them, please see a detailed list at [components overview guide](/xamarin/ui-customization/ui-components.md#android).

## Customize how users interact with annotations

To change the way users interact with annotations, including restricting which annotations can be created and edited, see [**Customizing annotation and PDF interaction**](/xamarin/annotation/annotation/customization.md).

## Customize annotation appearances

To change the way an annotation appears, see the [**Custom annotation appearance**](/xamarin/annotation/custom-annot-appearance.md) guide.

## Customize by modifying the source code

[Apryse's Mobile SDK for Android](/android/get-started/get-started.md) tools and demo package are completely open source. Any and all changes are possible by editing the source code directly. All source code can be found in `/lib/src`.

You can also integrate with source code directly in your application for easy code modification as described here: [How to integrate the Apryse libraries from source](/android/get-started/faq/run-tools-source.md).

## Next step

<a href="/xamarin/guides.md" class="button primary">Guides</a><a href="/xamarin/guides/api.md" class="button primary">API docs</a><a href="/xamarin/get-started/samples.md" class="button primary">Samples</a>


---

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