//1.storyboard

    //(1)

    //此处bundle:nil 等价于 [NSBundle mainBundle]

    //    SecondViewController *secondVc = [[UIStoryboard storyboardWithName:@"Main" bundle:nil]instantiateViewControllerWithIdentifier:@"Second"];

    //    SecondViewController *secondVc = [[UIStoryboard storyboardWithName:@"Main" bundle:[NSBundle mainBundle]]instantiateViewControllerWithIdentifier:@"Second"];

    //(2)

    //SecondViewController *secondVc = [[UIStoryboard storyboardWithName:@"SecondSB" bundle:nil]instantiateViewControllerWithIdentifier:@"Second"];

    //(3)

    //    SecondViewController *secondVc = [[UIStoryboard storyboardWithName:@"SecondSB" bundle:nil]instantiateInitialViewController];

    //2.与控制器同名的XIB文件 SecondViewController.xib init或initWithNibName加载

    //(1)

    //    SecondViewController *secondVc = [[SecondViewController alloc]init];

    //(2)

    //    SecondViewController *secondVc = [[SecondViewController alloc]initWithNibName:@"SecondViewController" bundle:nil];

    //3.与控制器不同名的XIB文件 View.xib loadNibNamed加载控制器的view

    /*

     在创建控制器的时候直接指定要加载xib作为控制器的view,名称不相干

     > 需要修改xib文件的fileOwner进行关联

     > 需要将fileOwner里面的view指向xib里面的view

     */

    //（1）initWithNibName---注重file owner

    SecondViewController *secondVc = [[SecondViewController alloc]initWithNibName:@"Second" bundle:nil];

    //（2）

    //    SecondViewController *secondVc = [[SecondViewController alloc]init];

    //    secondVc.view = [[[NSBundle mainBundle]loadNibNamed:@"SecondViewController" owner:nil options:nil] lastObject];

    //4.与控制器不同名的XIB文件 删除View,创建控制器  loadNibNamed---注重xib中内容

    //    SecondViewController *secondVc = [[[NSBundle mainBundle]loadNibNamed:@"SecondVC" owner:nil options:nil] lastObject];

Storyboard & XIB 自己的理解