我只是想知道是否可以像使用字体一样全局更改UINavigationBar's
标题:textAlignment
NSMutableDictionary *titleBarAttributes = [NSMutableDictionary dictionaryWithDictionary: [[UINavigationBar appearance] titleTextAttributes]];
[titleBarAttributes setValue:[UIFont fontWithName:myFontName] forKey:NSFontAttributeName];
[[UINavigationBar appearance] setTitleTextAttributes:titleBarAttributes];
[titleBarAttributes setValue:NSTextAlignmentLeft forKey:NSTextAlignment]
UIAppereance是否存在类似的东西?