ios - 如何在 PDFView 中 swift 适应来自 UIImage 的 PDF？

Question

我有一个应用程序可以捕获图像并将其转换为 pdf。然后它显示在 PDFView 中。但是，PDF 不适合我的 PDFView 的尺寸。如何缩放 pdf 以适应 PDFView？

当从 imagePickerController 中选择图像时，将执行以下函数:

// OUTLETS
@IBOutlet weak var myPDFView: PDFView!


 func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {

    print("image selected ...")
    // Get picked image info dictionary
    let image = info[UIImagePickerControllerOriginalImage] as! UIImage

    // Add captured and selected image to your Photo Library
    UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)

    // Create PDFDocument object and display in PDFView
    let document = createPDFDataFromImage(image: image)

    myPDFView.document = document
    myPDFView.scaleFactorForSizeToFit

    // Dimiss imagePicker
    dismiss(animated: true, completion: nil)

}


  func createPDFDataFromImage(image: UIImage) -> PDFDocument{

    let document = PDFDocument.init()
    let imagePDF = PDFPage.init(image: image)

    document.insert(imagePDF!, at: 0)
    return document
}

Answer 1

你可以设置autoScales为真

这是我的代码

pdfView.document = createPDF(image: #imageLiteral(resourceName: "Image-1"))

pdfView.minScaleFactor = 0.1
pdfView.maxScaleFactor = 5

pdfView.autoScales = true
pdfView.displayMode = .singlePageContinuous
pdfView.displayDirection = .vertical

然后像这样从图像创建一个 PDFPage:

func createPDF(image: UIImage) -> PDFDocument {
    let document = PDFDocument()

    guard let cgImage = image.cgImage else { return document }

    let image = UIImage(cgImage: cgImage, scale: image.scale, orientation: .downMirrored)

    guard let imagePDF = PDFPage(image: image) else { return document }

    document.insert(imagePDF, at: document.pageCount)

    return document
}