Working with magnification in Xamarin Pdf Viewer (SfPdfViewer)

19 May 20212 minutes to read

Magnification of the PDF document can be done in multiple ways and the different ways are explained below. By default, the PdfViewer supports panning and Ctrl+ mouse scroll (in XForms.UWP) to manipulate the magnification of the document.

Set custom zoom percentage

The users can set custom magnification factor between 100 and 300 to magnify the document displayed. The following code explains this,

<syncfusion:SfPdfViewer x:Name="pdfViewerControl" InputFileStream="{Binding PdfDocumentStream}" ZoomPercentage="150" />
pdfViewerControl.ZoomPercentage = 150;

Get custom zoom factor

The following code explains accessing zoom factor in which the document is displayed in the viewer.

<Entry Keyboard="Numeric" FontSize="18" x:Name="zoomPercentage" HorizontalTextAlignment="Center" VerticalOptions="Center" Text="{Binding ZoomPercentage, Source={x:Reference Name=pdfViewerControl}}"/>
int zoom = pdfViewerControl.ZoomPercentage;

On binding entry control to the ZoomPercentage property of the PDF Viewer instance, the current zoom percentage being displayed in PDF Viewer is displayed in the entry control, and the PDF Viewer will be zoomed based on the value entered.

Set maximum zoom percentage

The Xamarin PDF Viewer control allows you to set the maximum zoom percentage value for the PDF document being displayed. The following code example will set the maximum zoom percentage of PDF Viewer instance to 200.

<syncfusion:SfPdfViewer x:Name="pdfViewerControl" InputFileStream="{Binding PdfDocumentStream}" MaximumZoomPercentage="200" />
pdfViewerControl.MaximumZoomPercentage = 200;

Set minimum zoom percentage

The PDF Viewer control allows you to set the minimum zoom percentage value for the PDF document being displayed. The following code example will set the minimum zoom percentage of PDF Viewer instance to 10.

<syncfusion:SfPdfViewer x:Name="pdfViewerControl" InputFileStream="{Binding PdfDocumentStream}" MinimumZoomPercentage="10" />
pdfViewerControl.MinimumZoomPercentage = 10;

How to enable or disable the double-tap zoom

You can enable or disable the zooming of a PDF document on double-tap by setting the EnableDoubleTapZooming property of the PDF viewer to true or false respectively.

NOTE

The default value of the EnableDoubleTapZooming API is set to true.

//Disable the double-tap zoom
pdfViewer.EnableDoubleTapZooming = false;

NOTE

At present, this feature is available only in iOS

NOTE

You can also explore our Xamarin.Forms PDF Viewer example to knows the functionalities of each feature.