iOS之页面传值

//声明一个文本框和一个按钮

@property(strong,nonatomic)UITextField *textName;

@property(strong,nonatomic)UIButton *button;

ViewController.m

- (void)viewDidLoad {

    [super viewDidLoad];

    // Do any additional setup after loading the view, typically from a nib.

    self.textName=[[UITextField alloc] initWithFrame:CGRectMake(100, 100, 150, 40)];

    self.textName.borderStyle=1;

    self.button=[[UIButton alloc] initWithFrame:CGRectMake(100, 200, 100, 40)];

    self.button.backgroundColor=[UIColor redColor];

    [self.button setTitle:@"按钮" forState:UIControlStateNormal];

    [self.button addTarget:self action:@selector(nextPage) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:self.textName];

    [self.view addSubview:self.button];

    //指定代理

//    self.textName.delegate=self;

}

-(void)nextPage

{

    secondViewController *second=[[secondViewController alloc] init];

    second.str=self.textName.text;

    //代理

//    second.delegate=self;

    second.myblock=^(NSString *str)

    {

        self.textName.text=str;

    };

    [self presentViewController:second animated:YES completion:^{

        NSLog(@"转到下一页");

    }];

}

//协议方法的实现

-(void)postValue:(NSString *)value

{

    self.textName.text=value;

}

secondViewController.h

typedef void(^ValueBlock)(NSString *str);

//代理传值中的协议

@protocol postValueDelegate <NSObject>

-(void)postValue:(NSString *)value;

@end

//遵循协议

@interface secondViewController : UIViewController<UITextFieldDelegate>

@property(strong,nonatomic)NSString *str;

@property(strong,nonatomic)UITextField *txt2;

@property(strong,nonatomic)UIButton *button2;

//用协议定义的一个属性

@property(strong,nonatomic)id<postValueDelegate> delegate;

//代码块定义的一个属性

@property(strong,nonatomic)ValueBlock myblock;

secondViewController.m

- (void)viewDidLoad {

    [super viewDidLoad];

    // Do any additional setup after loading the view.

    self.view.backgroundColor=[UIColor grayColor];

    self.txt2=[[UITextField alloc] initWithFrame:CGRectMake(100, 100, 150, 40)];

    self.txt2.borderStyle=1;

    [self.view addSubview:self.txt2];

//    self.button2=[[UIButton alloc] initWithFrame:CGRectMake(100, 200, 100, 40)];

//    [self.button2 setTitle:@"返回" forState:UIControlStateNormal];

//    [self.button2 addTarget:self action:@selector(backPage) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:self.button2];

    //属性传值

    self.txt2.text=self.str;

    NSLog(@"str=%@",self.str);

    self.txt2.delegate=self;

}

//-(void)backPage

//{

//    //代理传值

//    if (self.delegate)

//    {

//        [self.delegate postValue:self.txt2.text];

//    }

//    

//    

//    [self dismissViewControllerAnimated:YES completion:^{

//        NSLog(@"返回");

//    }];

//}

-(BOOL)textFieldShouldReturn:(UITextField *)textField

{

    //代码块传值

    if (self.myblock)

    {

        self.myblock(textField.text);

    }

    if ([textField isFirstResponder])

    {

        [textField resignFirstResponder];

    }

    [self dismissViewControllerAnimated:YES completion:^{

        NSLog(@"返回");

    }];

    return YES;

}