GPPSignInButton没有文字

Question

我正在制作样本以使用Google+登录并阅读此文档：https://developers.google.com/+/mobile/ios/sign-in，集成有效，但登录按钮没有文字。并且我已经在GPPSignInButton

的故事板中将其子类化了

在我的viewDidLoad方法中，我定义了以下内容：

GPPSignIn *signIn = [GPPSignIn sharedInstance];
signIn.shouldFetchGooglePlusUser = YES;
signIn.shouldFetchGoogleUserEmail = YES;  // Uncomment to get the user's email
signIn.shouldFetchGoogleUserID = YES;

// You previously set kClientId in the "Initialize the Google+ client" step
signIn.clientID = kClientId;

// Uncomment one of these two statements for the scope you chose in the previous step
signIn.scopes = @[ kGTLAuthScopePlusLogin ];  // "https://www.googleapis.com/auth/plus.login" scope
//signIn.scopes = @[ @"profile" ];
// "profile" scope

// Optional: declare signIn.actions, see "app activities"
signIn.delegate = self;