text: 
  #import <UIKit/UIKit.h>
  
  @interface XLsn0wMiddleTabBarController : UITabBarController
  
  @end
  
  /*
   //创建窗口
   self.window = [[UIWindow alloc] init];
   self.window.frame = [UIScreen mainScreen].bounds;
   self.window.backgroundColor = [UIColor whiteColor];
   [self.window makeKeyAndVisible];
   //设置窗口的根控制器
   self.window.rootViewController = [[MiddleTabBarController alloc] init];
  */
  