我目前在 Controller 中显示来自 UIWebView 的 URL 内容，我想知道，如果没有连接到设备，我如何显示一条消息或显示一个警告对话框，你需要互联网连接才能显示内容？
我有以下代码:
import UIKit
class SecondView: UICollectionViewController {
override func viewDidLoad() {
super.viewDidLoad()
let myWebView:UIWebView = UIWebView(frame: CGRectMake(0, 0, UIScreen.mainScreen().bounds.width, UIScreen.mainScreen().bounds.height))
myWebView.loadRequest(NSURLRequest(URL: NSURL(string: "http://www.google.com")!))
self.view.addSubview(myWebView)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
}
谢谢!
这里是完整的工作代码:
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(sizeofValue(zeroAddress))
zeroAddress.sin_family = sa_family_t(AF_INET)
let defaultRouteReachability = withUnsafePointer(&zeroAddress) {
SCNetworkReachabilityCreateWithAddress(nil, UnsafePointer($0)).takeRetainedValue()
}
var flags: SCNetworkReachabilityFlags = 0
if SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) == 0 {
return false
}
let isReachable = (flags & UInt32(kSCNetworkFlagsReachable)) != 0
let needsConnection = (flags & UInt32(kSCNetworkFlagsConnectionRequired)) != 0
return (isReachable && !needsConnection) ? true : false
}
}
class SecondView: UICollectionViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewDidAppear(animated: Bool) {
if Reachability.isConnectedToNetwork() {
let myWebView:UIWebView = UIWebView(frame: CGRectMake(0, 0, UIScreen.mainScreen().bounds.width, UIScreen.mainScreen().bounds.height))
myWebView.loadRequest(NSURLRequest(URL: NSURL(string: "http://www.google.com")!))
self.view.addSubview(myWebView)
} else {
var alert = UIAlertController(title: "Alert", message: "you need internet connection to display the content", preferredStyle: UIAlertControllerStyle.Alert)
alert.addAction(UIAlertAction(title: "Ok", style: UIAlertActionStyle.Default, handler: nil))
self.presentViewController(alert, animated: true, completion: nil)
}
}
}