Determining the Clicked Position in the WPF PDF Viewer

17 Jun 20262 minutes to read

Use the PageClicked event of the WPF PDF Viewer control to capture the exact location where the user clicks on a PDF page. The event provides pixel coordinates, which can be converted to PDF points and adjusted for the viewer’s zoom level to yield accurate positions on the document.

Refer to the code snippet below for implementation details

private void PdfViewer_PageClicked(object sender, Syncfusion.Windows.PdfViewer.PageClickedEventArgs args)
 {
     //Get the current point where the mouse is clicked. The value is in pixels.
     Point currentPointInPixels = args.Position;

     //Convert the point from pixels to points.
     PdfUnitConvertor convertor = new PdfUnitConvertor();
     System.Drawing.PointF currentPoint = convertor.ConvertFromPixels( new System.Drawing.PointF((float)currentPointInPixels.X, (float)currentPointInPixels.Y), PdfGraphicsUnit.Point);

     //Convert the point based on the zoom factor.
     float zoomFactor = (float)pdfViewer.ZoomPercentage / 100;
     System.Drawing.PointF finalPoint = new System.Drawing.PointF(currentPoint.X / zoomFactor, currentPoint.Y / zoomFactor);

     //Display the point through message box.
     MessageBox.Show("The point clicked is: " + finalPoint.ToString());
 }
Private Sub PdfViewer_PageClicked(sender As Object, args As Syncfusion.Windows.PdfViewer.PageClickedEventArgs)
    ' Get the current point where the mouse is clicked. The value is in pixels.
    Dim currentPointInPixels As Point = args.Position

    ' Convert the point from pixels to points.
    Dim convertor As New PdfUnitConvertor()
    Dim currentPoint As System.Drawing.PointF = convertor.ConvertFromPixels(New System.Drawing.PointF(CSng(currentPointInPixels.X), CSng(currentPointInPixels.Y)), PdfGraphicsUnit.Point)

    ' Convert the point based on the zoom factor.
    Dim zoomFactor As Single = CSng(pdfViewer.ZoomPercentage) / 100
    Dim finalPoint As New System.Drawing.PointF(currentPoint.X / zoomFactor, currentPoint.Y / zoomFactor)

    ' Display the point through message box.
    MessageBox.Show("The point clicked is: " & finalPoint.ToString())
End Sub