应用程序更新后，WKWebView 在 web 视图中不显示 pdf 文件

Question

. Answers to this question are eligible for a +50 reputation bounty. TJ Rogers wants to to this question.

I just recently updated my app, and when I did so, I noticed that a web view that had been working just fine before the update no longer displays pdfs as it should. I made no modification to this portion of my code, so I'm guessing that this is an issue I'm having with with the current version of iOS, Swift, or both.

I'm running iOS 15 and Xcode 12.5.1

I also notice that if I revert to the old deprecated UIWebView, and change "characterEncodingName" to "textEncodingName" then it works just fine. But I'm not happy with this solution, because I'm not thrilled with reverting to deprecated code. I'm copying the code below that no longer works. Any feedback would be greatly appreciated.

import Foundation
import UIKit
import Parse
import MessageUI
import WebKit


class DocView: UIViewController, MFMailComposeViewControllerDelegate {
    
    @IBOutlet var webView: WKWebView!
    @IBOutlet var emailButton: UIBarButtonItem!
    @IBOutlet var navBar: UINavigationItem!
    
    var selectionPrev : String = String()
    var attachment : Data = Data()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        self.navigationController?.isNavigationBarHidden = false
        self.navBar.title = selectionPrev
        
        var query : PFQuery = PFQuery()
        do {
            let predicate = NSPredicate(format:"docName = %@", selectionPrev)
            query = PFQuery(className: "ParseDocs", predicate: predicate)
            query.limit = 1000
            let docsArray = try query.findObjects()
            for item in docsArray {
                let doc = item["docFile"] as! PFFile
                doc.getDataInBackground(block: {
                    (imageData: Data?, error: Error?) -> Void in
                    if (error == nil) {
                        self.attachment = imageData!
                        self.webView.load(imageData!, mimeType: "application/pdf", characterEncodingName: "utf-8", baseURL: URL(string: "http://www.dummyaddress.com")!)
                    } else {
                        print("error")
                    }
                    
                })
            }
        } catch {
            print("Error")
        }
        
        webView.contentMode = .scaleAspectFill
        
    }
}

Answer 1

characterEncodingName is supported from 9.0 to further no need to change to textEncodingName there is may be some other issue.