如何禁用编辑 PDF 注释？

Question

我正在 Swift 4.2 中构建 iOS 应用程序，可以对 PDF 文件进行签名。但如果将签名嵌入为 PDFAnnotation，它可以在苹果的预览应用程序或其他可以编辑 pdf 的应用程序中进行编辑。如何禁用编辑 PDFAnnoations ??

"Signature" 由 UIImage 转换手写 beizerpaths 创建。

class SignatureAnnotation: PDFAnnotation {

    var image: UIImage!

    init(with image: UIImage!, forBounds bounds: CGRect, withProperties properties: [AnyHashable : Any]?) {
        super.init(bounds: bounds,
                   forType: PDFAnnotationSubtype.freeText,
                   withProperties: properties) 
        self.image = image
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError()
    }

    override func draw(with box: PDFDisplayBox, in context: CGContext) {
        guard let cgImage = self.image.cgImage else { return }
        context.draw(cgImage, in: self.bounds)
    }

}

func embedSignatureToPDF() {
    let page = pdfView.currentPage
    let signatureAnnotation = SignatureAnnotation(with: signature, forBounds: signatureRect, withProperties: nil)
        page.addAnnotation(signatureAnnotation)
}

Answer 1

我终于找到解决办法了！

这里的思路是不使用PDFAnnotation！

签名是一张图片所以当用户保存 PDF

您将使用签名图片创建新的 PDF 并将其保存到同一个 PDF 文件

把你的签名放在你想要的地方你需要修改 X 和 Y image.draw(in: CGRect(x: 100, y: 100, width: 100, height: 100))

下面的代码将获取PDF的路径通常，它保存在文档文件夹中你只需要发送文件的路径还有签名图片该函数会将图像添加到 PDF 上方并保存

   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()
    }

Answer 2

把注解类型改成按钮怎么样？每次点击签名都会叠加，但是不能编辑

init(with image: UIImage!, forBounds bounds: CGRect, withProperties properties: [AnyHashable : Any]?) {
    super.init(bounds: bounds, forType: PDFAnnotationSubtype.widget, withProperties: properties)
    self.image = image
    self.isReadOnly = true
    self.widgetFieldType = .button
}

如何禁用编辑 PDF 注释？

How do I disable to edit PDFAnnotations?

pdf

pdf-annotations

swift

ios-pdfkit