> 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/viewer-components/user-bookmarks-i.md).

# User-defined bookmarks for Xamarin

Learn how to manage user-defined bookmarks in Xamarin.iOS with the PTBookmarkViewController class. Enhance your PDF viewer app with this feature today! The Apryse Xamarin SDK streamlines secure, serve

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

The [`PTBookmarkViewController`](https://sdk.apryse.com/api/xamarinios/tools/api/pdftron.PDF.Controls.PTBookmarkViewController.html) class shows a list of user-defined bookmarks that can be used to navigate through the document. The user-defined bookmarks are Apryse specific features that may not be shown in other PDF viewer apps. If you want to manage PDF bookmarks so that they can be processed in other standard PDF viewers, see the [outline view controller guide](/xamarin/guides/ios/bookmark/outline.md#ui-component).

![](https://653871032-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FgjsBtuYmcKhWOdM9VCg4%2Fuploads%2Fgit-blob-0c6671767140fba510adb152c66b82b412cd37b6%2F57576f04ec374441f9486f31f92fdcb519bf9119-1242x2208.png?alt=media)

*The user bookmarks control is part of the Tools library, so make sure you have* [*added the Tools library to your project*](/xamarin/ui-customization/setup.md)*.*

## Show a bookmark view controller

To create a new bookmark view controller instance and display it from another view controller, supply a `PTPDFViewCtrl` instance to the `PTBookmarkViewController` designated initializer:

{% tabs %}
{% tab title="C#" %}
{% code lineNumbers="true" %}

```csharp
var bookmarkViewController = new pdftron.PDF.Controls.PTBookmarkViewController (mPdfViewCtrl);
bookmarkViewController.BookmarkViewControllerBookmarkSelected += (sender, e) => {
    // perform custom action
    this.DismissViewController (true, null);
};
bookmarkViewController.BookmarkViewControllerDidCancel += (object sender, EventArgs e) => {
    this.DismissViewController (true, null);
};

var navigationController = new UINavigationController (bookmarkViewController);
if (UserInterfaceIdiomIsPad)
{
    navigationController.ModalPresentationStyle = UIModalPresentationStyle.Popover;
    navigationController.PopoverPresentationController.BarButtonItem = bookmarksButton;
}

this.PresentViewController (navigationController, true, null);
```

{% endcode %}
{% endtab %}
{% endtabs %}

{% hint style="info" %}
**The bookmark view controller must be pushed onto a navigation controller's stack before being shown.**
{% endhint %}

{% hint style="info" %}
**Presenting on iPads:**

The bookmark view controller is designed to be presented in a popover on iPads. To do so, you must provide the `PTBookmarkViewController`'s [`PopoverPresentationController`](https://docs.microsoft.com/en-us/dotnet/api/uikit.uipopoverpresentationcontroller) with either:

* a [`SourceRect`](https://docs.microsoft.com/en-us/dotnet/api/uikit.uipopoverpresentationcontroller.sourcerect#UIKit_UIPopoverPresentationController_SourceRect) AND
* a [`SourceView`](https://docs.microsoft.com/en-us/dotnet/api/uikit.uipopoverpresentationcontroller.sourceview#UIKit_UIPopoverPresentationController_SourceView)

OR

* a [`BarButtonItem`](https://docs.microsoft.com/en-us/dotnet/api/uikit.uipopoverpresentationcontroller.barbuttonitem#UIKit_UIPopoverPresentationController_BarButtonItem)

as in the example above.
{% endhint %}

You can set a delegate to be notified by the bookmark view controller when bookmarks are selected with the `PTBookmarkViewControllerDelegate` protocol. (See the CompleteReader example for usage of a `PTBookmarkViewController`.


---

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