我想要得到我之后收到的东西
 pdfView.autoScales = true
无法改变比例。
在@carmine的帮助下,我们得到了:
import UIKit
import PDFKit
class ViewController: UIViewController {
@IBOutlet weak var pdfView: PDFView!
override func viewDidLoad() {
    super.viewDidLoad()
    setPdfFile()
}
override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
    super.viewWillTransition(to: size, with: coordinator)
    self.pdfView.autoScales = true
}
func setPdfFile() {
    if let path = Bundle.main.path(forResource: "Swift.org - Getting Started", ofType: "pdf") {
        let url = URL(fileURLWithPath: path)
        if let pdfDocument = PDFDocument(url: url) {
            pdfView.autoScales = true
            pdfView.displayMode = .singlePageContinuous
            pdfView.displayDirection = .vertical
            pdfView.document …