RadPdfViewer : Get PDF coordinates based on mouse position

Hello Andrea,

Thank you for contacting us. 

If I understand your requirement correctly, you want to get the document location clicked position and convert the coordinates to start from the bottom left position. I am assuming that you want to do this on mouse click. In this case, first, you will need to convert the mouse click position to document location. In the following code snippet, the e.Location will be the mouse position from the Click event handler arguments.

var tt = element.TotalTransform;               
tt.Scale(this.radPdfViewer1.ScaleFactor, this.radPdfViewer1.ScaleFactor);
tt.Invert();
var pointInDoc = tt.TransformPoint(e.Location);

To convert the documentation location you need only to transform the Y value. For this purpose, you need the height of the current page. You can get it from the current page element.

Location documentlocation = new Location()
                {
                    Left = pointInDoc.X,
                    Top = pointInDoc.Y,
                    Page = element.Page,
                };
RadFixedPageElement element = radPdfViewer1.ElementTree.GetElementAtPoint(args.Location) as RadFixedPageElement;
var transformtPoint = element.Size.Height - documentlocation.Top;

Here is the result from my side:

I am also attaching the sample project which I used to test your requirement. I am not sure that this will cover all your cases, but I think it will be a good starting point. You can extend the approach to fit your application.

I hope that I was able to help you.

Regards,
Dinko | Tech Support Engineer
Progress Telerik