Swift 4您可以使用图像注释PDF吗？ [英] Swift 4 Can you annotate a PDF with an image

问题描述

我对Swift编程很新，我已经创建了一个应用程序，用于简化任务，我以编程方式填写现有PDF上的字段。我已经将签名捕获为UIImage，我想将其作为注释添加到PDF中，就像其他字段一样。这可能吗？

I'm fairly new to Swift programming and I've created an app for work to simplify a task where I programmatically fill-in fields on an existing PDF. I've captured a signature as a UIImage and I'd like to add this to the PDF as an annotation like the rest of the fields. Is this possible?

// Annotate Signature
let signatureFieldBounds = CGRect(x:390, y:142, width:100, height:30)
let signatureField = PDFAnnotation(bounds: signatureFieldBounds, forType: .stamp, withProperties: nil)
signatureField.fieldName = FieldNames.signature.rawValue
signatureField.backgroundColor = UIColor.clear
sigImage?.draw(in: signatureFieldBounds)

page.addAnnotation(signatureField)

我也尝试过：signatureField.stampName = sigImage as！ UIImage而不是绘制函数但这会给出错误'无法分配类型'UIImage的值'来键入'String？''

I've also tried: signatureField.stampName = sigImage as! UIImage instead of the draw function but this gives the error 'Cannot assign value of type 'UIImage' to type 'String?''

屏幕截图显示了我注释的内容：

The screenshot shows what I get annotated:

任何帮助都可以非常感谢!!

Any help at all would be greatly appreciated!!

推荐答案

这对我来说也很棘手，但我想出来了。

This was tricky for me too, but I figured it out.

创建自定义PDFAnnotation，然后覆盖draw方法以在pdf上下文中绘制图像。

Create a custom PDFAnnotation, then override the draw method to draw the image in the pdf context.

class ImageStampAnnotation: PDFAnnotation {

var image: UIImage!

// A custom init that sets the type to Stamp on default and assigns our Image variable
init(with image: UIImage!, forBounds bounds: CGRect, withProperties properties: [AnyHashable : Any]?) {
    super.init(bounds: bounds, forType: PDFAnnotationSubtype.stamp, withProperties: properties)

    self.image = image
}

required init?(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
}


override func draw(with box: PDFDisplayBox, in context: CGContext) {

    // Get the CGImage of our image
    guard let cgImage = self.image.cgImage else { return }

    // Draw our CGImage in the context of our PDFAnnotation bounds
    context.draw(cgImage, in: self.bounds)

 } 
}

然后，只需将其添加到文档中

Then, just add it to the document

guard let signatureImage = signatureImage, let page = pdfContainerView.currentPage else { return }
    let pageBounds = page.bounds(for: .cropBox)
    let imageBounds = CGRect(x: pageBounds.midX, y: pageBounds.midY, width: 200, height: 100)
    let imageStamp = ImageStampAnnotation(with: signatureImage, forBounds: imageBounds, withProperties: nil)
    page.addAnnotation(imageStamp)

我写了一篇关于我是如何做到的中篇文章，为它添加了一个手势识别器和一个抓住签名的画布：
https://medium.com/@rajejones/add-a-signature-to-pdf- using-pdfkit-with-swift-7f13f7faad3e

I wrote a medium article on how I did it, added a gesture recognizer to it and a canvas to grab a signature: https://medium.com/@rajejones/add-a-signature-to-pdf-using-pdfkit-with-swift-7f13f7faad3e

这篇关于Swift 4您可以使用图像注释PDF吗？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！