我是 facebook SDK 和 iOS 开发人员的新手，当用户登录 facebook 时，我的应用程序出现问题，当我使用相同的帐户 fb 登录时，我的应用程序总是显示此登录对话框：
我希望我的应用程序仅在第一次登录 fb 帐户时显示该对话框，但我不知道该怎么做，这是我的代码：
- (void)sessionStateChanged:(FBSession *)session state:(FBSessionState) state error:(NSError *)error {
switch (state) {
case FBSessionStateOpen:
if (!error) {
mainViewController *mainView = [self.storyboard instantiateViewControllerWithIdentifier:@"mainView"];
[self.navigationController pushViewController:mainView animated:YES];
// We have a valid session
NSLog(@"User session found");
}
break;
case FBSessionStateClosed:
case FBSessionStateClosedLoginFailed:
[FBSession.activeSession closeAndClearTokenInformation];
break;
default:
break;
}
[[NSNotificationCenter defaultCenter]
postNotificationName:FBSessionStateChangedNotification
object:session];
if (error) {
UIAlertView *alertView = [[UIAlertView alloc]
initWithTitle:@"Error"
message:error.localizedDescription
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles:nil];
[alertView show];
}
}
- (BOOL)openSessionWithAllowLoginUI:(BOOL)allowLoginUI {
NSArray *permissions = [[NSArray alloc] initWithObjects:
@"email",
@"user_likes",
nil];
return [FBSession openActiveSessionWithReadPermissions:permissions
allowLoginUI:allowLoginUI
completionHandler:^(FBSession *session,
FBSessionState state,
NSError *error) {
[self sessionStateChanged:session
state:state
error:error];
}];
}
- (IBAction)authLogin:(id)sender {
[self openSessionWithAllowLoginUI:YES];
}
我使用 fb sdk 3.2 和 ios 模拟器 6.1