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通知传值(NSNotificationCenter)

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2014-07-19 20:57?315人閱讀?評論(0)?收藏?舉報

NSNotificationCenteruitableviewcellNSNotificationios開發界面

通知傳值

//流程:
1.注冊通知
2.通知中心,發送一條消息通知----------其中name名字千萬不要寫錯了,會出現在3個地方
3.實現通知中心內部的方法,并實現傳值
4.第四步,消息發送完,要移除掉

代碼如下:

[objc]?view plaincopy

#import?"FirstViewController.h"??

#import?"SecondViewController.h"??

#import?"UIButton+Create.h"??

@interface?FirstViewController?()??

{??

????UILabel?*?_label;??

}??

@end??

@implementation?FirstViewController??

-?(void)dealloc??

{??

????[_label?release];??

????//第四步,消息發送完,要移除掉??

????[[NSNotificationCenter?defaultCenter]removeObserver:self?name:@"labelTextNotification"?object:nil];??

????[super?dealloc];??

}??

-?(id)initWithNibName:(NSString?*)nibNameOrNil?bundle:(NSBundle?*)nibBundleOrNil??

{??

????self?=?[super?initWithNibName:nibNameOrNil?bundle:nibBundleOrNil];??

????if?(self)?{??

????????//?Custom?initialization??

????}??

????return?self;??

}??

-?(void)viewDidLoad??

{??

????[super?viewDidLoad];??

??????

????self.view.backgroundColor?=?[UIColor?redColor];??

????self.navigationItem.title?=?@"首頁";??

??????

????_label?=?[[UILabel?alloc]initWithFrame:CGRectMake(50,?80,?200,?30)];??

????_label.backgroundColor?=?[UIColor?greenColor];??

????[self.view?addSubview:_label];??

??????

????UIButton?*?button?=?[UIButton?systemButtonWithFrame:CGRectMake(100,?120,?50,?50)?title:@"Push"?target:self?action:@selector(didClickButtonAction)];??

????[self.view?addSubview:button];??

??????

????//第二步,通知中心,發送一條消息通知----------其中name名字千萬不要寫錯了,會出現在3個地方??

????[[NSNotificationCenter?defaultCenter]addObserver:self?selector:@selector(showLabelText:)?name:@"labelTextNotification"?object:nil];??

??????

???

??????

????//?Do?any?additional?setup?after?loading?the?view.??

}??

-?(void)showLabelText:(NSNotification?*)notification??

{??

????//第三,實現通知中心內部的方法,并實現傳值??

????id?text?=?notification.object;??

????_label.text?=?text;??

}??

-?(void)didClickButtonAction??

{??

??????

????

????SecondViewController?*?secondVC?=?[[SecondViewController?alloc]init];??

????[self.navigationController?pushViewController:secondVC?animated:YES];??

????[secondVC?release];??

}??

-?(void)didClick:(NSString?*)text??

{??

????_label.text?=?text;??

}??

-?(void)didReceiveMemoryWarning??

{??

????[super?didReceiveMemoryWarning];??

????//?Dispose?of?any?resources?that?can?be?recreated.??

}??

@end??

[objc]?view plaincopy

#import?"SecondViewController.h"??

#import?"FirstViewController.h"??

#import?"UIButton+Create.h"??

@interface?SecondViewController?()??

{??

????UITextField?*?_textField;//創建一個輸入框??

}??

@end??

@implementation?SecondViewController??

-?(void)dealloc??

{??

????[_textField?release];??

????[super?dealloc];??

}??

-?(id)initWithNibName:(NSString?*)nibNameOrNil?bundle:(NSBundle?*)nibBundleOrNil??

{??

????self?=?[super?initWithNibName:nibNameOrNil?bundle:nibBundleOrNil];??

????if?(self)?{??

????????//?Custom?initialization??

????}??

????return?self;??

}??

-?(void)viewDidLoad??

{??

????[super?viewDidLoad];??

????self.view.backgroundColor?=?[UIColor?orangeColor];??

????self.navigationItem.title?=?@"第二頁";??

????

??????

????_textField?=?[[UITextField?alloc]initWithFrame:CGRectMake(50,?80,?200,?30)];??

????_textField.borderStyle?=?UITextBorderStyleRoundedRect;??

????[self.view?addSubview:_textField];??

??????

????UIButton?*?button?=?[UIButton?systemButtonWithFrame:CGRectMake(100,?120,?50,?50)?title:@"Back"?target:self?action:@selector(didClickButtonAction)];??

????[self.view?addSubview:button];??

???

??????

????//?Do?any?additional?setup?after?loading?the?view.??

}??

-?(void)didClickButtonAction??

{??

??????

????//第一步注冊通知??

????[[NSNotificationCenter?defaultCenter]postNotificationName:@"labelTextNotification"?object:_textField.text];??

????[self.navigationController?popToRootViewControllerAnimated:YES];??

}??

-?(void)didReceiveMemoryWarning??

{??

????[super?didReceiveMemoryWarning];??

????//?Dispose?of?any?resources?that?can?be?recreated.??

}??

@end??

轉載于:https://blog.51cto.com/9453125/1561046

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