这对我有用:
//Step 1. create and store an ACAccountStore in an ivar
ACAccountStore* as = [[ACAccountStore alloc] init];
self.accountStore = as;
[as release];
//Step 2. Get the facebook account type
//Do not use the constant if you are in iOS5, use this string:@"com.apple.facebook"
ACAccountType* at = [self.accountStore accountTypeWithAccountTypeIdentifier: @"com.apple.facebook"];
//Step 3. request access to the facebook account, passing your facebook app id
__block typeof(self) bself = self;
[self.accountStore requestAccessToAccountsWithType:at
options:@{(NSString *)ACFacebookAppIdKey: kFBAppId }
completion:^(BOOL granted, NSError *error)
{
//Step 4. Check if the account is integrated natively
//Note: if granted is NO, check for the error to see what's going on.
BOOL nativeAccount = granted == YES && [bself.accountStore accountsWithAccountType:at];
//Step 5. clean the account store.
bself.accountStore = nil;
}];