登录后Facebook SDK Objective-C触发事件

Question

我是IOS应用程序开发新手，这是我第一次将Facebook SDK集成到应用程序中。 我使用我的初始视图控制器通过Facebook SDK对用户进行身份验证，并在身份验证后将其重定向到另一个视图控制器。另外，一旦他点击注销，我希望能够将用户重定向回该初始视图控制器。

我用下面的代码（viewDidLoad函数内），以Facebook登录按钮添加到我的观点：

FBSDKLoginButton *loginButton = [[FBSDKLoginButton alloc] init]; 

// setting the facebook button position 
float screenHeight = [[UIScreen mainScreen] bounds].size.height; 
float screenWidth = [[UIScreen mainScreen] bounds].size.width; 
CGPoint origin = CGPointMake(screenWidth/2, screenHeight - 100); 

// Optional: Place the button in the center of your view. 
loginButton.center = origin; 
[self.view addSubview:loginButton]; 

按钮工作正常，但我注意到，之后我登录时，所有视图控制器生命周期函数中的[FBSDKAccessToken currentAccessToken]是nil。基本上，我的页面加载后，似乎这个值由Facebook SDK初始化。

有没有什么办法可以在访问令牌被初始化后执行一个函数，以便我可以成功地重定向到不同的控制器？或者是否有任何功能可以帮助我实现这种行为？ 同样，我希望能够将用户重定向到这个初始视图控制器，一旦他从不同的视图点击注销按钮。

Answer 1

我发现，到目前为止，这个问题最简单的办法是设置视图控制器作为登录按钮的代表，并实现以下功能：

首先，你必须使用此协议：

@interface LoginController()<FBSDKLoginButtonDelegate> 

然后，设置视图控制器作为按钮的委托

loginButton.delegate = self; 

最后，你必须确保实施以下2种方法

- (void) loginButton:(FBSDKLoginButton *)loginButton 
didCompleteWithResult:(FBSDKLoginManagerLoginResult *)result 
       error:(NSError *)error{ 
    //use your custom code here 
    //redirect after successful login 
} 
- (void) loginButtonDidLogOut:(FBSDKLoginButton *)loginButton{ 
    //use your custom code here 
    //redirect after successful logout 
} 

Answer 2

我想你必须使用FBGraphApi，它会在用户登录成功时给你回电。

试试下面的代码：

-(void)FBLoginWithViewController:(UIViewController *)viewController withCompletion:(FBDataBlock)block 
{ 
    [login logInWithReadPermissions: @[@"public_profile"] 
      fromViewController:viewController 
      handler:^(FBSDKLoginManagerLoginResult *permissionResult, NSError *error) { 
       if (error) { 

        block(permissionResult,error,nil); 

       } else if (permissionResult.isCancelled) { 

        block(permissionResult,error,nil); 

       } else { 

        [[[FBSDKGraphRequest alloc] initWithGraphPath:@"me" parameters:@{ @"fields" : @"id,name,picture,email,friends"}] 
         startWithCompletionHandler:^(FBSDKGraphRequestConnection *connection, id response, NSError *error) { 

           block(permissionResult,error,response); 
         }]; 
       } 
      }]; 

} 

通过调用上面的函数，你会得到回电ComplitionBlock。

Answer 3

以下是获取用户信息的完整且完整的代码。

FBSDKLoginManager *login = [[FBSDKLoginManager alloc] init]; 
[login 
logInWithReadPermissions: @[@"public_profile", @"user_friends", @"email"] 
fromViewController:self 
handler:^(FBSDKLoginManagerLoginResult *result, NSError *error) { 
    if (error) { 
     DLog(@"Process error======%@",error.description); 
     indicators.hidden=YES; 
     [indicators stopAnimating]; 
    } else if (result.isCancelled) { 
     DLog(@"Cancelled"); 
     indicators.hidden=YES; 
     [indicators stopAnimating]; 
    } else { 

     if ([FBSDKAccessToken currentAccessToken]) { 



      [[[FBSDKGraphRequest alloc] initWithGraphPath:@"me" parameters:@{@"fields": @"id, name, link, first_name, last_name, picture.type(large), email, birthday, bio ,location ,friends ,hometown , gender ,friendlists"}] 
       startWithCompletionHandler:^(
              FBSDKGraphRequestConnection *connection, id result, NSError *error) { 
        if (!error) 
        { 

         // NSLog(@"fetched user:%@", result); 

         // [self fetchingFacebookFriends]; 

         [defFacebookData setObject:[result objectForKey:@"email"] forKey:@"fbEmail"]; 

         [defFacebookData setObject:[result objectForKey:@"id"] forKey:@"fbID"]; 


         //PASS ID 
         getFbid = [result objectForKey:@"id"]; 
    NSLog(@"getFbid========>%@",getFbid); 

         //PASS FIRST NAME 
         getFbFirstName=[result objectForKey:@"first_name"]; 

    NSLog(@"first======>%@",getFbFirstName); 

         //PASS LAST NAME 
         getFBlastName=[result objectForKey:@"last_name"]; 
    NSLog(@"first======>%@",getFBlastName); 

         //PASS EMAIL 
         getFbemail=[result objectForKey:@"email"]; 
    NSLog(@"first======>%@",getFbemail); 

         //PASS PHONE 
         getfbGender=[result objectForKey:@"gender"]; 
    NSLog(@"first======>%@",getfbGender); 


         [defFacebookData setObject:[result objectForKey:@"name"] forKey:@"fbName"]; 

         // Image 
         FBSDKGraphRequest *request = [[FBSDKGraphRequest alloc] 
                initWithGraphPath:[NSString stringWithFormat:@"me/picture?type=large&redirect=false"] 
                parameters:nil 
                HTTPMethod:@"GET"]; 
         [request startWithCompletionHandler:^(FBSDKGraphRequestConnection *connection, 
                  id fbImageResult, 
                  NSError *error) { 

NSString *strURL = [NSString stringWithFormat:@"%@",[[fbImageResult objectForKey:@"data"] objectForKey:@"url"]]; 

    NSLog(@"strURL=====>%@",strURL); 

[defFacebookData setObject:strURL forKey:@"fbImage"]; 

          [defFacebookData synchronize]; 


          NSDictionary *fbdict=[NSDictionary dictionaryWithObjectsAndKeys:getFbid,@"id",getFbFirstName,@"first_name",getFBlastName,@"last_name",getFbemail,@"email",getfbGender,@"gender",strURL,@"fbImage", nil]; 

          NSLog(@"done=========>%@",fbdict); 

    UIStoryboard*storyboard=[AppDelegate storyBoardType]; 

    NSUserDefaults *defaults =[NSUserDefaults standardUserDefaults]; 


    BOOL fblogin =[defaults boolForKey:@"KeyEditProfile"]; 

     if (fblogin) 
      { 

       UIStoryboard*Storyboard=[AppDelegate storyBoardType]; 
       DashboardVC* tabbarController = (DashboardVC*)[Storyboard instantiateViewControllerWithIdentifier:@"DashboardVCId"]; 



       indicators.hidden=YES; 
       [indicators stopAnimating]; 

       [self.navigationController pushViewController:tabbarController animated:YES]; 

     } 

    else 
    { 
    EditFBVC *cpvc=(EditFBVC*)[storyboard instantiateViewControllerWithIdentifier:@"EditFBVCId"]; 
    NSLog(@"get fb id ===%@",getFbid); 


    cpvc.dictFacebookdict =fbdict; 

    cpvc.strFBlogin =@"fbAllDataValue"; 

     indicators.hidden=YES; 
     [indicators stopAnimating]; 

    [self.navigationController pushViewController:cpvc animated:YES]; 

    } 
         }]; 
        } 
        else{ 

         DLog(@"error is %@", error.description); 
        } 
       }]; 
     } 
    } 
}];