一：两个view之间的数据相互传递。1）这里两个view间切换主要用到的是每个类对象固有的属性(modalTransitionStyle)来设置过渡模式（也就是过渡(切换)到别的界面）。2）还会用到委托(delegate)来响应事件方法。3）要特别注意协议delegate：[plain] view plaincopy@protocol delegate 
     
        -(void)myupdata:(NSString *)str;  @end  在此程序中的作用：是从视图2（MyModalTransition (定义一个id 类型遵循上诉协议的属性：mydelegate  。mydalegate会得到视图1类，从而调用其实现的方法。)）返回到视图1（MyObserver（遵循上诉协议实现其myupdata方法））的重要渠道。二：新建程序：第一个viewMyObserver.h[plain] view plaincopy#import 
      
         #import "MyClass.h"  #import "MyModalTransition.h"  @interface MyObserver : UIViewController 
       
         {      UITextField *mytext01;  }  @property(retain) MyClass *myclass;  //定义另一个类MyModalTransition的属性  @property(nonatomic,retain) MyModalTransition *mymtra;  @property (nonatomic, strong) IBOutlet UITextField *mytext01;  -(void)myupdata:(NSString*) str;- (IBAction)btnpress:(id)sender;  -(void)exit;  @end  MyObserver.m[plain] view plaincopy#import "MyObserver.h"    @implementation MyObserver  @synthesize mytext01;  @synthesize mymtra;  - (void)viewDidLoad  {      //点击屏幕键盘的return键时，键盘响应exit方法，放弃第一响应者退出            [self.mytext01 addTarget:self action:@selector(exit) forControlEvents:UIControlEventEditingDidEndOnExit];            [super viewDidLoad];      // Do any additional setup after loading the view from its nib.  }    -(void)myupdata:(NSString *)str{      self.mytext01.text=str;      //放弃过渡模式，开始开始显示第一个view      [self dismissModalViewControllerAnimated:YES];  }    - (IBAction)btnpress:(id)sender {            self.mymtra=[[MyModalTransition alloc] init];      //定义模型过渡样式      mymtra.modalTransitionStyle=UIModalTransitionStylePartialCurl;      //mymtra.modalTransitionStyle=UIModalTransitionStyleCoverVertical;      //数据传递      mymtra.message=self.mytext01.text;      //把当前类self传给另一个视图的委托      mymtra.mydelegate=self;            //呈现模型      [self presentModalViewController:mymtra animated:YES];  }  -(void)exit{  //放弃第一响应者身份      [self resignFirstResponder];  }  第二个viewMyModalTransition.h[plain] view plaincopy#import 
        
           //在这定义协议的原因是：这样mydelegate属性遵循协议的时候本身就有了myupdata方法，其实现部分就是在上一个视图MyObserver里。当mydelegate获得MyObserver时就可以调用这个方法了。  @protocol delegate 
         
            -(void)myupdata:(NSString *)str;  @end    @interface MyModalTransition : UIViewController {      UITextField *mytext02;  }  //遵循delegate协议就拥有了其myupdata方法  @property(assign) id 
          
           mydelegate; @property (nonatomic, strong) IBOutlet UITextField *mytext02; @property(copy) NSString *message; - (IBAction)btnbackpress:(id)sender; @end MyModalTransition.m[plain] view plaincopy#import "MyModalTransition.h" @implementation MyModalTransition @synthesize mytext02; @synthesize mydelegate; @synthesize message; //点击按钮 - (IBAction)btnbackpress:(id)sender { NSString *str=mytext02.text; //值传递 [self.mydelegate myupdata:str]; } #pragma mark - View lifecycle - (void)viewDidLoad { self.mytext02.text=message; [super viewDidLoad]; // Do any additional setup after loading the view from its nib. } 运行结果：