ios - 将 PDF 转换为 UIImage

Question

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()
}

我的问题是 PDF 转换为图像，但如何在 View 中打开图像然后向左、向右、向上和向下滑动怎么可能

Answer 1

swift 3:

func convertPDFPageToImage(page:Int) {

    let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
    let filePath = documentsURL.appendingPathComponent("pathLocation").path

    do {

        let pdfdata = try NSData(contentsOfFile: filePath, options: NSData.ReadingOptions.init(rawValue: 0))

        let pdfData = pdfdata as CFData
        let provider:CGDataProvider = CGDataProvider(data: pdfData)!
        let pdfDoc:CGPDFDocument = CGPDFDocument(provider)!
        pageCount = pdfDoc.numberOfPages;
        let pdfPage:CGPDFPage = pdfDoc.page(at: page)!
        var pageRect:CGRect = pdfPage.getBoxRect(.mediaBox)
        pageRect.size = CGSize(width:pageRect.size.width, height:pageRect.size.height)

        print("\(pageRect.width) by \(pageRect.height)")

        UIGraphicsBeginImageContext(pageRect.size)
        let context:CGContext = UIGraphicsGetCurrentContext()!
        context.saveGState()
        context.translateBy(x: 0.0, y: pageRect.size.height)
        context.scaleBy(x: 1.0, y: -1.0)
        context.concatenate(pdfPage.getDrawingTransform(.mediaBox, rect: pageRect, rotate: 0, preserveAspectRatio: true))
        context.drawPDFPage(pdfPage)
        context.restoreGState()
        let pdfImage:UIImage = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()            

        self.imageView.image = pdfImage

    }
    catch {

    }

}