我正在创建一个Facebook应用程序.我已经使用FBSDKLoginManager类实现了登录.当我第一次登录Facebook时,成功块返回FBSDKLoginManagerLoginResult对象,该对象包含访问令牌对象(FBSDKAccessToken对象),该对象使用完整的方式共享包含.But在第二次(重新启动应用程序后),当我尝试获取访问令牌使用函数[FBSDKAccessToken currentAccessToken]返回nil.那么如何获得访问令牌(FBSDKAccessToken对象)第二次没有再次登录Facebook.
解决方法
尝试这段代码.基于Facebook SDK 4.0版
AppDalegate.m
- (BOOL)application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation {
return [[FBSDKApplicationDelegate sharedInstance] application:application
openURL:url
sourceApplication:sourceApplication
annotation:annotation];
}
ViewController.m
- (IBAction)btnFacebookPressed:(id)sender {
FBSDKLoginManager *login = [[FBSDKLoginManager alloc] init];
[login logInWithReadPermissions:@[@"email"] handler:^(FBSDKLoginManagerLoginResult *result,NSError *error)
{
if (error)
{
// Process error
}
else if (result.isCancelled)
{
// Handle cancellations
}
else
{
if ([result.grantedPermissions containsObject:@"email"])
{
NSLog(@"result is:%@",result);
[self fetchUserInfo];
}
}
}];
}
-(void)fetchUserInfo
{
if ([FBSDKAccessToken currentAccessToken])
{
NSLog(@"Token is available : %@",[[FBSDKAccessToken currentAccessToken]tokenString]);
[[[FBSDKGraphRequest alloc] initWithGraPHPath:@"me" parameters:@{@"fields": @"id,name,link,first_name,last_name,picture.type(large),email,birthday,bio,location,friends,hometown,friendlists"}]
startWithCompletionHandler:^(FBSDKGraphRequestConnection *connection,id result,NSError *error) {
if (!error)
{
NSLog(@"resultis:%@",result);
}
else
{
NSLog(@"Error %@",error);
}
}];
}
}
viewDidLoad调用此方法后,您可以在登录后获取访问令牌
[self fetchUserInfo];
