逆向传值的几种方法整理 iOS

第一种：代理传值

第二个控制器：

@protocol WJSecondViewControllerDelegate <NSObject>
- (void)changeText:(NSString*)text;
@end
 @property(nonatomic,assign)id<WJSecondViewControllerDelegate>delegate;

- (IBAction)buttonClick:(UIButton*)sender {
_str = sender.titleLabel.text;
[self.delegate changeText:sender.titleLabel.text];
[self.navigationController popViewControllerAnimated:YES];
}

第一个控制器:

- (IBAction)pushToSecond:(id)sender {
WJSecondViewController *svc = [[WJSecondViewController alloc]initWithNibName:@"WJSecondViewController" bundle:nil];
svc.delegate = self;
svc.str = self.navigationItem.title;
[self.navigationController pushViewController:svc animated:YES];
[svc release];
}
- (void)changeText:(NSString *)text{
self.navigationItem.title = text;
}

第二种：通知传值

第一个控制器：

 //注册监听通知
 [[NSNotificationCenter defaultCenter] addObserver:self         selector:@selector(limitDataForModel:) name:@"NOV" object:nil];
- (void)limitDataForModel:(NSNotification *)noti{
self.gamesInfoArray = noti.object;
}

第二个控制器：

//发送通知
  [[NSNotificationCenter defaultCenter]     postNotificationName:@"NOV" object:gameArray];

第三种：单例传值

Single是一个单例类，并且有一个字符串类型的属性titleName
在第二个控制器：

- (IBAction)buttonClick:(UIButton*)sender {
Single *single = [Single sharedSingle];
single.titleName = sender.titleLabel.text;
[self.navigationController popViewControllerAnimated:YES];
}

第一个控制器：

- (void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
Single *single = [Single sharedSingle];
self.navigationItem.title = single.titleName;
}

第四种：block传值

第二个控制器：

@property (nonatomic,copy) void (^changeText_block)(NSString*);
- (IBAction)buttonClick:(UIButton*)sender {
_str = sender.titleLabel.text;
self.changeText_block(sender.titleLabel.text);
[self.navigationController popViewControllerAnimated:YES];
}

第一个控制器：

- (IBAction)pushToSecond:(id)sender {
WJSecondViewController *svc = [[WJSecondViewController alloc]initWithNibName:@"WJSecondViewController" bundle:nil];
svc.str = self.navigationItem.title;
[svc setChangeText_block:^(NSString *str) {
    >self.navigationItem.title = str;
}]；
[self.navigationController pushViewController:svc animated:YES];
}

第五种：extern传值

第二个控制器：

 extern NSString *btn;
- (IBAction)buttonClick:(UIButton*)sender {
btn = sender.titleLabel.text;
[self.navigationController popViewControllerAnimated:YES];
}

第一个控制器:

NSString *btn = nil;
- (void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
self.navigationItem.title = btn;
}

第六种：KVO传值

第一个控制器:

- (void)viewDidLoad {
[super viewDidLoad];
 _vc =[[SecondViewController alloc]init];
//self监听vc里的textValue属性
[_vc addObserver:self forKeyPath:@"textValue" options:0 context:nil];   
}

第二个控制器:

- (IBAction)buttonClicked:(id)sender {
self.textValue = self.textField.text;
[self.navigationController popViewControllerAnimated:YES];
}