swift draw image on pdf

swift_draw_image_on_pdf.swift

    func drawOnPDF(path: String) {
        
        // Get existing Pdf reference
        let pdf = CGPDFDocumentCreateWithURL(NSURL(fileURLWithPath: path))
        
        // Get page count of pdf, so we can loop through pages and draw them accordingly
        let pageCount = CGPDFDocumentGetNumberOfPages(pdf);
        
        // Write to file
        UIGraphicsBeginPDFContextToFile(path, CGRectZero, nil)
        
        // Write to data
        //var data = NSMutableData()
        //UIGraphicsBeginPDFContextToData(data, CGRectZero, nil)
        
        for index in 1...pageCount {
            let page = CGPDFDocumentGetPage(pdf, index)
            let pageFrame = CGPDFPageGetBoxRect(page, kCGPDFMediaBox)
                    
            UIGraphicsBeginPDFPageWithInfo(pageFrame, nil)
                    
            var ctx = UIGraphicsGetCurrentContext()
            
            // Draw existing page
            CGContextSaveGState(ctx);
            CGContextScaleCTM(ctx, 1, -1);
            CGContextTranslateCTM(ctx, 0, -pageFrame.size.height);
            CGContextDrawPDFPage(ctx, page);
            CGContextRestoreGState(ctx);
            
            // Draw image on top of page
            var image = UIImage(named: "signature3")
            image?.drawInRect(CGRectMake(100, 100, 100, 100))
            
            // Draw red box on top of page
            //UIColor.redColor().set()
            //UIRectFill(CGRectMake(20, 20, 100, 100));
        }
        
        
        UIGraphicsEndPDFContext()
    }

Thanks man.. have been searching for this. What if I want to draw a semi transparent rectangle not an image?

Exactly what I was looking for. Even the PDF-on-top transparency works. Thanks!

how do you apply this to a uiview?

Thank you very much, you are a lifesaver!

I did convert it correctly to Swift 4.2

   func drawOnPDF(path: String , signatureImage:UIImage) {
        
        // Get existing Pdf reference
    let pdf = CGPDFDocument(NSURL(fileURLWithPath: path))
        
        // Get page count of pdf, so we can loop through pages and draw them accordingly
    let pageCount = pdf?.numberOfPages
    
    
        // Write to file
        UIGraphicsBeginPDFContextToFile(path, CGRect.zero, nil)
        
        // Write to data
        //var data = NSMutableData()
        //UIGraphicsBeginPDFContextToData(data, CGRectZero, nil)
        
        for index in 1...pageCount! {
            
            let page =  pdf?.page(at: index)

            let pageFrame = page?.getBoxRect(.mediaBox)

            
            UIGraphicsBeginPDFPageWithInfo(pageFrame!, nil)
                    
            let ctx = UIGraphicsGetCurrentContext()
            
            // Draw existing page
            ctx!.saveGState()
            
            ctx!.scaleBy(x: 1, y: -1)
          
            ctx!.translateBy(x: 0, y: -pageFrame!.size.height)
            //CGContextTranslateCTM(ctx, 0, -pageFrame.size.height);
            ctx!.drawPDFPage(page!)
            ctx!.restoreGState()
            
            // Draw image on top of page
            let image = signatureImage
            image.draw(in: CGRect(x: 100, y: 100, width: 100, height: 100))
            // Draw red box on top of page
            //UIColor.redColor().set()
            //UIRectFill(CGRectMake(20, 20, 100, 100));
        }
        
        
        UIGraphicsEndPDFContext()
    }

This works only on first page of the pdf file. Using this code actually removes the actual content on pdf and replaces it with the new image if there more than one pages in the pdf.

thank you, it work to me .

What is the path?

@MerrickWang1, path is location to pdf file stored on local

Thanks :)