往UISegmentedControl上添加几个控制器

 #import "RootViewController.h"

 #import "LoginViewController.h"

 #import "RegistViewController.h"

 #import "PasswardViewController.h"

 #import "RootView.h"

 @interface RootViewController ()

 @property (nonatomic, strong) RootView *rootView;

 @property (nonatomic, strong) LoginViewController *loginVC;

 @property (nonatomic, strong) RegistViewController *registVC;

 @property (nonatomic, strong) PasswardViewController *passwardVC;

 @end

 @implementation RootViewController

 - (void)loadView {

     self.rootView = [[RootView alloc] initWithFrame:[UIScreen mainScreen].bounds];

     self.view = self.rootView;

 }

 - (void)viewDidLoad {

     [super viewDidLoad];

     // 初始化视图控制器

     self.loginVC = [[LoginViewController alloc] init];

     self.registVC = [[RegistViewController alloc] init];

     self.passwardVC = [[PasswardViewController alloc] init];

     // segment添加一个事件

     [self.rootView.segment addTarget:self action:@selector(click:) forControlEvents:UIControlEventValueChanged];

 }

 // 实现点击事件

 - (void)click:(UISegmentedControl *)sender {

     switch (sender.selectedSegmentIndex) {

         case :

             // 移除父视图中最上面的子视图

             [[self.rootView.subviews objectAtIndex:] removeFromSuperview];

             // 添加新视图

             [self.rootView addSubview:self.loginVC.view];

             // 把分段选择器显示在最外层

             [self.rootView bringSubviewToFront:self.rootView.segment];

             break;

         case :

             // 移除父视图中最上面的子视图

             [[self.rootView.subviews objectAtIndex:] removeFromSuperview];

             // 添加新视图

             [self.rootView addSubview:self.registVC.view];

             // 把分段选择器显示在最外层

             [self.rootView bringSubviewToFront:self.rootView.segment];

             break;

         case :

             // 移除父视图中最上面的子视图

             [[self.rootView.subviews objectAtIndex:] removeFromSuperview];

             // 添加新视图

             [self.rootView addSubview:self.passwardVC.view];

             // 把分段选择器显示在最外层

             [self.rootView bringSubviewToFront:self.rootView.segment];

             break;

         default:

             break;

     }

 }

 @end