加载custom bundle

NSString *resourceBundle = [[NSBundle mainBundle] pathForResource:@"Resources" ofType:@"bundle"];
NSLog(@"resourceBundle: %@", resourceBundle);
NSString *earth = [[NSBundle bundleWithPath:resourceBundle] pathForResource:@"Resource" ofType:@"jpg" inDirectory:@"Images/MoreImages"];

使用Custom bundle，访问内部的子文件夹，需要指定inDirectory参数