IOS - 通知(NSNotification)

標籤：

#import "ViewController.h"#import "SViewController.h"@interface ViewController ()@property (weak, nonatomic) IBOutlet UILabel *showLabel;@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view, typically from a nib.    //1.註冊為觀察者，監聽B視圖中的通知    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(AMethod:) name:@"MyNotificationName" object:nil];}-(void)AMethod:(NSNotification *)notification{    //2.擷取通知攜帶的資料，更新label的文本資訊    NSDictionary *dictData = [notification userInfo];    NSString *str = [dictData objectForKey:@"MyUserInfoKey"];    self.showLabel.text = str;}- (IBAction)goSVC:(id)sender {        SViewController *svc = [[SViewController alloc] init];        [self presentViewController:svc animated:YES completion:^{            } ];}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    //3.移除所有通知    [[NSNotificationCenter defaultCenter]removeObserver:self];}@end-----------#import "SViewController.h"@interface SViewController ()@property (strong, nonatomic) UITextField *textField;@end@implementation SViewController- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view.    self.view.backgroundColor = [UIColor redColor];        self.textField = [[UITextField alloc] initWithFrame:CGRectMake(20, 200, 100, 30)];    self.textField.backgroundColor = [UIColor whiteColor];    [self.view addSubview:self.textField];        UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];    btn.frame = CGRectMake(50, 60, 30, 20);    [btn setTitle:@"go" forState:UIControlStateNormal];        [self.view addSubview:btn];        [btn addTarget:self action:@selector(clickGoVC:) forControlEvents:UIControlEventTouchUpInside];    }- (void)clickGoVC:(id)sender {        //返回視圖A並發布通知    [self dismissViewControllerAnimated:YES completion:^{        //1.建立userInfo攜帶的資訊        NSString *str = self.textField.text;        NSDictionary *dictData = [NSDictionary dictionaryWithObject:str forKey:@"MyUserInfoKey"];        //2.發布資訊        [[NSNotificationCenter defaultCenter] postNotificationName:@"MyNotificationName" object:nil userInfo:dictData];    }];}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end

 

IOS - 通知(NSNotification)