請代表打開由AppDelegate外部的URL標識的資源

Question

我有這樣的代碼，要求委託人打開由URL標識的資源，並希望將此代碼放在AppDelegate文件之外，即在不同的文件中：

-(BOOL)application:(UIApplication *)application 
       openURL:(NSURL *)url 
    sourceApplication:(NSString *)sourceApplication 
      annotation:(id)annotation { 

     NSLog(@"url --> %@", url); 
     //Do something... 
     return YES; 
    } 

它工作正常，如果它在AppDelegate，但如果我在另一個文件中有此方法，它將無法運行。

爲了給出更多關於爲什麼我使用這種方法的內容，涉及到一個認證過程。因此，在我的應用程序的某個時候，Safari會打開並提示用戶使用某些憑據。 然後我用URL Scheme +一些信息啓動我的應用程序，例如myurl://someinfo

Answer 1

將代碼留在AppDelegate中，而是在另一個類中使用該方法。

定義全球的AppDelegate在AppDelegate.h這樣

#define APP_DELEGATE ((AppDelegate *)[[UIApplication sharedApplication] delegate]) 

這樣做後，你可以調用AppDelegate.m的方法在代碼的任何地方，像這樣：

[APP_DELEGATE methodYouWantToCall]; 

Answer 2

好像使用NSNotificationCenter可能是您的要求的最佳選擇。

在AppDelegate中發佈使用NSNotificationCenter

-(BOOL)application:(UIApplication *)application 
      openURL:(NSURL *)url 
      sourceApplication:(NSString *)sourceApplication 
      annotation:(id)annotation 
{ 
    NSLog(@"url --> %@", url); 
    // Do something... 
    // 1 - Post recieved URL by usig NSNotificationCenter 
    [[NSNotificationCenter defaultCenter] postNotificationName:@"APP_LAUNCHED_BY_URL_SCHEMA_NOTIFICATION" object:url]; 
    return YES; 
} 

，並在自定義類中的通知（例如：視圖控制器）添加以下代碼

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 
    // 2 - Add observer to the notification name posted from AppDelegate 
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(appDidLaunchedByURLSchemaNotification:) name:@"APP_LAUNCHED_BY_URL_SCHEMA_NOTIFICATION" object:nil]; 
} 
-(void)appDidLaunchedByURLSchemaNotification:(NSNotification *)notification 
{ 
    // 3 - Here you can get the URL Object posted with notification,you will get this Callback on every launch of your application using Your Custom URL Scheme by other applications. 
    NSURL *url = notification.object; 
    NSLog(@"url --> %@", url); 
} 

請記住刪除添加的觀察者在自定義類的-dealloc

-(void)dealloc 
{ 
    [[NSNotificationCenter defaultCenter] removeObserver:self]; 
} 

H2H，玩得開心編碼:)

Answer 3

這與Naresh的回答非常相似，因爲所有來自NSNotificationCenter的通知都以相同的方式工作。

基本上，您將選擇通知的名稱（例如：@"NOTIFICACION_NAME"），然後您需要接收該事件的每個對象都將訂閱具有該名稱的所有通知。

所以，在你的應用程序代理，你將發佈（例如，「廣播」）這個名字的通知：

-(BOOL)application:(UIApplication *)application 
     openURL:(NSURL *)url 
     sourceApplication:(NSString *)sourceApplication 
     annotation:(id)annotation 
{ 
    // First, create a dictionary with all the data needed to pass. 
    NSDictionary *notificationInfo = @{ 
             @"url"    : url, 
             @"sourceApplication" : sourceApplication, 
             @"annotation"  : annotation 
             }; 
    // Post the notification to all objects that listen to it. 
    [[NSNotificationCenter defaultCenter] postNotificationName:@"NOTIFICATION_NAME" 
                 object:self 
                 userInfo:notificationInfo]; 
} 

現在，我們需要趕在你需要它的其他文件通知。所以：

- (instancetype)init { 
    self = [super init]; 
    if (self) { 

    // Subscribe to the notifications called "NOTIFICATION_NAME" 
    // The "object" parameter is nil so we get notification from all objects that post that particular notification name. 
    // It could also be [[UIApplication sharedApplication] delegate] to receive notifications only from the app delegate. 
    // If you process the event in a UIViewController, do this in viewDidLoad instead of init. 
    [[NSNotificationCenter defaultCenter] addObserver:self 
              selector:@selector(openedWithURLScheme:) 
               name:@"NOTIFICATION_NAME" 
               object:nil]; 
    } 
} 

- (void)dealloc { 
    // Unsubscribe from all notifications at dealloc time. If you don't do this, 
    // your app will crash when the app delegate posts the notifications 
    // after this particular object was deallocated. 
    // If it's a UIViewController, do this in viewDidUnload. 
    [[NSNotificationCenter defaultCenter] removeObserver:self]; 
} 

- (void)openedWithURLScheme:(NSNotification *)notification { 
    // The notification was received, so this method is called with the 
    // notification object as a parameter. Now we get the dictionary 
    // we sent with all the info. 
    NSDictionary *notificationInfo = notification.userInfo; 

    // Now get the data you need: 
    NSURL *url = notificationInfo[@"url"]; 
    NSString *sourceApplication = notificationInfo[@"sourceApplication"]; 
    id annotation = notificationInfo[@"annotation"]; 

    // Do what you need with that info... 
} 

在簡單的話：當你的應用程序代理接收到特定的方法，我們廣播接收到的「聽」（觀察）特定的通知每一個對象（通知）的信息。應該使用NSDictionary完成。

欲瞭解更多信息，請閱讀official documentation at Apple website。