改变输入框的placehould的颜色

UIColor *color = [UIColor whiteColor];

    _usernameTextField.attributedPlaceholder = [[NSAttributedString alloc] initWithString:@"请输入账号" attributes:@{NSForegroundColorAttributeName: color}];

附带找window的跟视图控制器

UIWindow *window = [UIApplication sharedApplication].keyWindow;

    UINavigationController *nav = [[UINavigationController alloc]initWithRootViewController:loginVC];

    window.rootViewController = nav;

改变输入框的placehould的颜色

原文：http://www.cnblogs.com/Lovexiaohuzi/p/5552472.html