> 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/file-comparison-i.md).

# Compare PDF files in Xamarin

Learn how to use the Apryse SDK for powerful file comparison in Xamarin.iOS. Create a file comparison view controller and retrieve the output with customizable colors. See sample code for generating v

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

The Apryse SDK provides powerful file comparison functionality. An example of this capability is shown below by comparing two PDF pages and highlighting the difference between them in red.

| File 1                                                                                                                                                                                                                                           | File 2                                                                                                                                                                                                                                           | Difference                                                                                                                                                                                                                                       |
| ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| ![](https://653871032-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FgjsBtuYmcKhWOdM9VCg4%2Fuploads%2Fgit-blob-a3fd7c34d0ff2a47e6601b447be105a324c06894%2Ffa37a99afc74d0f696f8e308cd3b454c8f31c321-1400x1314.png?alt=media) | ![](https://653871032-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FgjsBtuYmcKhWOdM9VCg4%2Fuploads%2Fgit-blob-40d2ec0260cda7b9d3c91aa3c985c8ba78d956a1%2F9c80c17e2ad977f79cb9e3d34b3ab0f5d0368aaa-1400x1314.png?alt=media) | ![](https://653871032-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FgjsBtuYmcKhWOdM9VCg4%2Fuploads%2Fgit-blob-6f241352dd19f13186e41fd9c0ad6f03d02395bb%2Ff8761eb598ae30bbba73fcee581ebcac7c18c186-1400x1314.png?alt=media) |

## Show a file comparison view controller

The [`PTDiffViewController`](https://sdk.apryse.com/api/xamarinios/tools/api/pdftron.PDF.Controls.PTDiffViewController.html) class shows a control to select two documents and create a new file showing the visual difference between them with customizable colors.

![](https://653871032-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FgjsBtuYmcKhWOdM9VCg4%2Fuploads%2Fgit-blob-2727db11cebe81b27da1067349242ce355ea58cf%2Ffaee6f763f2c48ed2ea67aa5a9c43a3d6fe9a5b4-750x1624.png?alt=media)

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

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

```csharp
// Initialize a file comparison view controller.
var diffController = new PTDiffViewController();

diffController.DidCreateDiffFileAtURL += (sender, e) =>
{
    // Handle created diff file.
};

var navigationController = new UINavigationController(diffController);
if (!UserInterfaceIdiomIsPhone)
{
    navigationController.ModalPresentationStyle = UIModalPresentationStyle.Popover;

    navigationController.PopoverPresentationController.SourceView = btn;
    navigationController.PopoverPresentationController.SourceRect = btn.Bounds;
}

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

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

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

{% hint style="info" %}
**Retrieving the file comparison output.**

The `PTDiffViewController` creates an output file showing the visual difference between the two documents in a temporary directory and returns an [`NSURL`](https://developer.apple.com/foundation/nsurl/) with the file's location via a delegate method. To save and display the file, you must conform to the `PTDiffViewControllerDelegate` protocol.
{% endhint %}

## File comparison sample code

The following sample code demonstrates how to use `PDFNet` to generate a document displaying the visual difference between two PDF pages:

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

```csharp
// Xamarin sample code coming soon
```

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


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