Google+登录按钮自定义

是的,有办法直接登录Google+.

在AppDelegate,添加这个,

- (BOOL)application:(UIApplication *)application
            openURL:(NSURL *)url
  sourceApplication:(NSString *)sourceApplication
         annotation:(id)annotation
{
       return [GPPURLHandler handleURL:url
                      sourceApplication:sourceApplication
                             annotation:annotation];   
}

并且您的登录视图控制器应该添加此代码部分.

- (void)loginWithGooglePlus
{
    [GPPSignIn sharedInstance].clientID = kClientID;
    [GPPSignIn sharedInstance].scopes= [NSArray arrayWithObjects:kGTLAuthScopePlusLogin, nil];
    [GPPSignIn sharedInstance].shouldFetchGoogleUserID=YES;
    [GPPSignIn sharedInstance].shouldFetchGoogleUserEmail=YES;
    [GPPSignIn sharedInstance].delegate=self;

    [[GPPSignIn sharedInstance] authenticate];
}

- (void)finishedWithAuth:(GTMOAuth2Authentication *)auth
                   error:(NSError *)error
{
    if (!error)
    {
        NSLog(@"Google+ login successful");
    }
    else
    {
        NSLog(@"Error: %@", error);
    }
}

kClientID是您从Google注册的应用中获取的应用客户端ID.当然你需要设置delegate(GPPSignInDelegate).