openURL回调？

Question

用户拒绝定位，我将用户发送到设置应用程序上的位置设置：

UIApplication.sharedApplication().openURL(NSURL(string:"prefs:root=LOCATION_SERVICES")!)

用户从设置应用程序授权定位，返回我的应用程序并在左上角显示Back to App

我怎么知道他回到应用程序了？viewDidAppear不起作用

Answer 1

你可以通过检查AppDelegate's 来轻松地检测：-

func applicationWillEnterForeground(application: UIApplication!) {

或者通过NSNotificationCenter在视图控制器的viewDidLoad()中注册通知：-

NSNotificationCenter.defaultCenter().addObserver(self, selector: "applicationWillEnterForeground", name: UIApplicationWillEnterForegroundNotification, object: nil)


//calling selector method
 func applicationWillEnterForeground() {
            println("did enter foreground")
        }

Answer 2

试试UIApplicationDelegate applicationDidBecomeActive。

Answer 3

在viewController中使用NSNotificationCenter

在viewDidLoad上调用它

- (void)registerAppEnterForeground
{
    [[NSNotificationCenter defaultCenter]
     addObserver:self
     selector:@selector(applicationWillEnterForeground)
     name:UIApplicationWillEnterForegroundNotification
     object:nil];
}


-(void)applicationWillEnterForeground
{
 /*HANDLE YOUR CODE HERE*/
}