> 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/guides/xamarin-forms-document-viewer.md).
# Document viewer for Xamarin.Forms (fully featured)
Learn how to customize a ContentPage in Xamarin with Microsoft's guide. Understand rendering on different platforms using ContentPage, ExportRenderer, and PageRenderer. Click for complete sample code!
Before you get started, we recommend you have a look at Microsoft's comprehensive guide on [Customizing a ContentPage](https://docs.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/custom-renderer/contentpage/). It is important that you understand how Xamarin renders the same page on different platforms using `ContentPage`, `ExportRenderer` and `PageRenderer`. In this guide, you will learn how to create a fully featured document viewer and editor as page renderer on each platform.
Complete sample code can be found here:
Get Xamarin.Forms sample
The rendering process can be taken advantage of to implement platform-specific customization by creating a custom renderer for a `ContentPage` on each platform. The process for doing this is as follows:
1. [Create](/xamarin/guides/xamarin-forms.md#creating-the-xamarinforms-page) a Xamarin.Forms page.
2. [Consume](/xamarin/guides/xamarin-forms.md#consuming-the-xamarinforms-page) the page from Xamarin.Forms.
3. [Create](/xamarin/guides/xamarin-forms.md#creating-the-page-renderer-on-each-platform) the custom renderer for the page on each platform.
## Create the Xamarin.Forms Page
An unaltered `ContentPage` can be added to the shared Xamarin.Forms project, as shown in the following XAML code example:
{% tabs %}
{% tab title="XAML" %}
{% code lineNumbers="true" %}
```xaml
```
{% endcode %}
{% endtab %}
{% endtabs %}
Similarly, the code-behind file for the `ContentPage` should also remain unaltered, as shown in the following code example:
{% tabs %}
{% tab title="C#" %}
{% code lineNumbers="true" %}
```csharp
public partial class AdvancedViewerPage : ContentPage
{
public AdvancedViewerPage()
{
// Document viewer contains toolbar, let's hide the global one
NavigationPage.SetHasNavigationBar(this, false);
InitializeComponent();
}
}
```
{% endcode %}
{% endtab %}
{% endtabs %}
An instance of the `AdvancedViewerPage` will be used to display document viewer on each platform. Customization of the control will be carried out in the custom renderer, so no additional implementation is required in the `AdvancedViewerPage` class.
## Consume the Xamarin.Forms Page
The empty `AdvancedViewerPage` must be displayed by the Xamarin.Forms application. This occurs when a button on the `MainPage` instance is tapped, which in turn executes the `OnOpenAdvancedViewerButtonClicked` method, as shown in the following code example:
{% tabs %}
{% tab title="C#" %}
{% code lineNumbers="true" %}
```csharp
async void OnOpenAdvancedViewerButtonClicked(object sender, EventArgs e)
{
await Navigation.PushAsync(new AdvancedViewerPage());
}
```
{% endcode %}
{% endtab %}
{% endtabs %}
This code simply navigates to the `AdvancedViewerPage`, on which custom renderers will customize the page's appearance on each platform.
## Create the Page Renderer on each Platform
The `AdvancedViewerPage` instance is rendered by platform-specific `AdvancedViewerPageRenderer` classes, which all derive from the `PageRenderer` class for that platform. This results in each `AdvancedViewerPage` instance being rendered with document viewer, as shown in the following GIF:
| Android | iOS |
| ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|  |  |
### Create the Page Renderer on iOS
The following code example shows the page renderer for the iOS platform:
{% tabs %}
{% tab title="C#" %}
{% code lineNumbers="true" %}
```csharp
[assembly: ExportRenderer(typeof(AdvancedViewerPage), typeof(AdvancedViewerPageRenderer))]
namespace CustomRenderer.iOS
{
public class AdvancedViewerPageRenderer : PageRenderer
{
private PTTabbedDocumentViewController mTabViewController;
protected override void OnElementChanged(VisualElementChangedEventArgs e)
{
base.OnElementChanged(e);
if (e.OldElement != null || Element == null)
{
return;
}
try
{
SetupUserInterface();
SetupEventHandlers();
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine(@" ERROR: ", ex.Message);
}
}
//...
}
}
```
{% endcode %}
{% endtab %}
{% endtabs %}
where the document viewer can be setup as follows:
{% tabs %}
{% tab title="C#" %}
{% code lineNumbers="true" %}
```csharp
void SetupUserInterface()
{
mTabViewController = new PTTabbedDocumentViewController();
UINavigationController navigationController = new UINavigationController(mTabViewController);
AddChildViewController(navigationController);
View.AddSubview(navigationController.View);
navigationController.DidMoveToParentViewController(this);
NSUrl fileURL = NSBundle.MainBundle.GetUrlForResource("sample", "pdf");
mTabViewController.OpenDocumentWithURL(fileURL);
}
```
{% endcode %}
{% endtab %}
{% endtabs %}
### Create the Page Renderer on Android
The following code example shows the page renderer for the Android platform:
{% tabs %}
{% tab title="C#" %}
{% code lineNumbers="true" %}
```csharp
[assembly: ExportRenderer(typeof(AdvancedViewerPage), typeof(AdvancedViewerPageRenderer))]
namespace CustomRenderer.Droid
{
public class AdvancedViewerPageRenderer : PageRenderer
{
private DocumentView mDocumentView;
public ViewerPageRenderer(Context context) : base(context)
{
}
protected override void OnElementChanged(ElementChangedEventArgs e)
{
base.OnElementChanged(e);
if (e.OldElement != null || Element == null)
{
return;
}
try
{
SetupUserInterface();
SetupEventHandlers();
AddView(view);
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine(@" ERROR: ", ex.Message);
}
}
//...
}
}
```
{% endcode %}
{% endtab %}
{% endtabs %}
where the document viewer can be setup as follows:
{% tabs %}
{% tab title="C#" %}
{% code lineNumbers="true" %}
```csharp
void SetupUserInterface()
{
activity = this.Context as Activity;
view = activity.LayoutInflater.Inflate(Resource.Layout.AdvancedViewerLayout, this, false);
mDocumentView = view.FindViewById(Resource.Id.document_view);
var context = this.Context;
FragmentManager childManager = null;
if (context is AppCompatActivity)
{
var activity = context as AppCompatActivity;
var manager = activity.SupportFragmentManager;
var fragments = manager.Fragments;
if (fragments.Count > 0)
{
childManager = fragments[0].ChildFragmentManager;
}
if (childManager != null)
{
mDocumentView.OpenDocument(GetFile(), "", GetConfig(), childManager);
}
}
}
```
{% endcode %}
{% endtab %}
{% endtabs %}
Click [here for ](https://github.com/ApryseSDK/xamarin-forms-sample/blob/master/ContentPage/Droid/DocumentView.cs)[`DocumentView`](https://github.com/ApryseSDK/xamarin-forms-sample/blob/master/ContentPage/Droid/DocumentView.cs)[ class](https://github.com/ApryseSDK/xamarin-forms-sample/blob/master/ContentPage/Droid/DocumentView.cs) implementation.
## Configure the Viewer
The document viewer is highly customizable and can be configured to remove/modify many components.
* For Android please see [this guide.](/xamarin/basic-operations/basics/fragment-config.md)
* For iOS, please see [this guide.](/xamarin/basic-operations/basics/viewer/viewer-configuration.md)
## Sample
Try out the complete sample here: [https://github.com/ApryseSDK/xamarin-forms-sample](https://github.com/ApryseSDK/xamarin-forms-sample/).
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