在我的新 iOS 应用程序中,我必须登录 Facebook 并获取用户详细信息。我在这里阅读了教程 - http://developers.facebook.com/docs/tutorials/ios-sdk-tutorial/authenticate/并研究了 Scrumptious 和其他示例。但我无法理解流程。
我创建了一个示例项目来进行 Facebook 登录(下面的代码) - 但有以下主要问题:
- 为什么当我再次单击登录按钮时应用程序要求授权 - 在我在 Facebook 上单击一次“确定”后
下面是我的代码 -
@implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// See if the app has a valid token for the current state.
if (FBSession.activeSession.state == FBSessionStateCreatedTokenLoaded)
{
// To-do, show logged in view --- LOGGED IN : Already Login
// Yes, so just open the session (this won't display any UX).
UIWindow *window = [UIApplication sharedApplication].keyWindow;
ViewController *rootViewController = (ViewController *)window.rootViewController;
[rootViewController openSession];
}
return YES;
}
- (BOOL)application:(UIApplication *)application
openURL:(NSURL *)url
sourceApplication:(NSString *)sourceApplication
annotation:(id)annotation
{
return [FBSession.activeSession handleOpenURL:url];
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
[FBSession.activeSession handleDidBecomeActive];
}
@implementation ViewController
@synthesize lblStatus;
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
lblStatus.text = @"Login Now";
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (IBAction)login:(id)sender
{
[self openSession];
}
- (void)sessionStateChanged:(FBSession *)session
state:(FBSessionState) state
error:(NSError *)error
{
switch (state) {
case FBSessionStateOpen:
{
// Connection is Open
lblStatus.text = @"FBSessionStateOpen";
}
break;
case FBSessionStateClosed:
case FBSessionStateClosedLoginFailed:
{
[FBSession.activeSession closeAndClearTokenInformation];
// Connection is Closed / Login Failed
lblStatus.text = @"FBSessionStateClosed";
}
break;
default:
break;
}
}
- (void)openSession
{
[FBSession openActiveSessionWithReadPermissions:nil
allowLoginUI:YES
completionHandler:
^(FBSession *session,
FBSessionState state, NSError *error)
{
[self sessionStateChanged:session state:state error:error];
}];
}
答案---->
感谢 nerowolfe 的建议。
以下是我连接到 Facebook 的完整解决方案。我的下一个任务是现在获取用户数据。
@implementation AppDelegate
- (BOOL)application:(UIApplication *)application
openURL:(NSURL *)url
sourceApplication:(NSString *)sourceApplication
annotation:(id)annotation
{
return [FBSession.activeSession handleOpenURL:url];
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
[FBSession.activeSession handleDidBecomeActive];
}
--------------------------
@implementation ViewController
@synthesize lblStatus;
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
lblStatus.text = @"Login Now";
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (IBAction)login:(id)sender
{
[self openSession];
}
- (void)sessionStateChanged:(FBSession *)session
state:(FBSessionState) state
error:(NSError *)error
{
switch (state) {
case FBSessionStateOpen:
{
// Connection is Open
lblStatus.text = @"FBSessionStateOpen";
}
break;
case FBSessionStateClosed:
case FBSessionStateClosedLoginFailed:
{
[FBSession.activeSession closeAndClearTokenInformation];
// Connection is Closed / Login Failed
lblStatus.text = @"FBSessionStateClosed";
}
break;
default:
break;
}
}
- (void)openSession
{
if(FBSession.activeSession.isOpen)
{
[FBSession openActiveSessionWithReadPermissions:nil
allowLoginUI:NO
completionHandler:
^(FBSession *session,
FBSessionState state, NSError *error)
{
[self sessionStateChanged:session state:state error:error];
}];
}
else
{
[FBSession openActiveSessionWithReadPermissions:nil
allowLoginUI:YES
completionHandler:
^(FBSession *session,
FBSessionState state, NSError *error)
{
[self sessionStateChanged:session state:state error:error];
}];
}
}
- (IBAction)logout:(id)sender
{
[FBSession.activeSession closeAndClearTokenInformation];
if(FBSession.activeSession.isOpen)
lblStatus.text = @"Open Still";
else
lblStatus.text = @"Close";
}