小编Mr *_*ite的帖子

我已经在xcode 9中使用wkwebiew完成了webview应用程序。在网站上，有一些部分需要下载pdf文件，该pdf文件只能查看，但如何制作可以下载到我们的iphone。可以给我一些提示吗，这是我的代码

class ViewController: UIViewController,WKNavigationDelegate,UIWebViewDelegate {

@IBOutlet weak var activityIndicator: UIActivityIndicatorView!
@IBOutlet weak var webView: WKWebView!
@IBOutlet var containerView: UIView? = nil
@IBOutlet weak var backButton: UIButton!
@IBOutlet weak var forwardButton: UIButton!

override func viewDidLoad() {
    super.viewDidLoad()

    //webview
    self.view.addSubview(self.activityIndicator)
    self.view.addSubview(self.webView)
    let url:URL = URL(string : "https://www.facebook.com")!
    let urlRequest : URLRequest = URLRequest(url: url)
    webView.load(urlRequest)
    webView.navigationDelegate = self


    //activity indicator
    self.webView.addSubview(self.activityIndicator)
    self.activityIndicator.startAnimating()
    self.webView.navigationDelegate = self
    self.activityIndicator.hidesWhenStopped = true
    self.webView.navigationDelegate=self;


    //refresh
    webView.scrollView.bounces = true
    let refreshControl = UIRefreshControl()
    refreshControl.addTarget(self, action: #selector(ViewController.refreshWebView), for: …

我想在xcode 9中实现可达性功能，但是在达到可达性类时出现此错误，如何解决此错误？“类型为“ SCNetworkReachability的值？” 没有成员“ takeRetainedValue””。这是我的代码

import UIKit
import Foundation
import SystemConfiguration

public class reachability {

    class func isConnectedToNetwork() -> Bool {

        var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
        zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress))
        zeroAddress.sin_family = sa_family_t(AF_INET)


        let defaultRouteReachability = withUnsafePointer(&zeroAddress) {
            SCNetworkReachabilityCreateWithAddress(nil, UnsafePointer($0)).takeRetainedValue()
        }

        var flags: SCNetworkReachabilityFlags = SCNetworkReachabilityFlags(rawValue: 0)
        if SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) == 0 {
            return false
        }

        let isReachable = (flags.rawValue & UInt32(kSCNetworkFlagsReachable)) != 0 …