犹豫在初始化导航栏的时候 设置了[UIBarButtonItem appearance] 为clearColor
所以导致在在h5里的界面弹出的输入框中, 完成 和 清除 按钮一直不能正常显示, 都是半透明状态, 而单纯加载本地的html5
UIBarButtonItem *item = [UIBarButtonItem appearance];
NSMutableDictionary *attrs = [NSMutableDictionary dictionary];
attrs[NSForegroundColorAttributeName] = [UIColor blueColor];
[item setTitleTextAttributes:attrs forState:UIControlStateNormal];
