iOS傳值－NSNotification

標籤：

說明：通知在頁面傳值中，通知是非常簡單便捷的方式，具體過程是，發行者發布通知到通知中樞，訂閱者從發布中心獲得最新通知，具體結構如

實現代碼：

1，建立Single View Application工程，建立一個SecondViewController，用於作為發送端

2，在ViewController.m中添加UIButton用於跳轉到SecondViewController，UILabel用於顯示通知

@interface ViewController (){    UILabel *_label;}@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    //添加UIButton，用於跳轉到SecondViewController    UIButton *btn = [[UIButton alloc] initWithFrame:CGRectMake(20, 200, 300, 44)];    [btn setTitle:@"ToSecondViewController" forState:UIControlStateNormal];    btn.backgroundColor = [UIColor grayColor];    [btn addTarget:self action:@selector(toSecondViewController) forControlEvents:UIControlEventTouchUpInside];    [self.view addSubview:btn];        //添加UILabel，用於顯示SecondViewController傳過來的值    _label = [[UILabel alloc] initWithFrame:CGRectMake(20, 100, 300, 44)];    _label.backgroundColor = [UIColor yellowColor];    [self.view addSubview:_label];    }- (void)toSecondViewController {    SecondViewController *second = [[SecondViewController alloc] init];    [self presentViewController:second animated:YES completion:nil];}

 

3，在SecondViewController.m中添加UIButton，用於發送通知並且跳回ViewController，UILabel用於輸入通知數據

@interface SecondViewController (){    UITextField *_textField;}@end@implementation SecondViewController- (void)viewDidLoad {    [super viewDidLoad];    self.view.backgroundColor = [UIColor whiteColor];    //添加一個按鈕用於返回ViewController    UIButton *btn = [[UIButton alloc] initWithFrame:CGRectMake(20, 200, 300, 44)];    [btn setTitle:@"BackToViewController" forState:UIControlStateNormal];    btn.backgroundColor = [UIColor blueColor];    [btn addTarget:self action:@selector(postNotification) forControlEvents:UIControlEventTouchUpInside];    [self.view addSubview:btn];        //添加一個UITextField    _textField = [[UITextField alloc] initWithFrame:CGRectMake(20, 100, 300, 44)];    _textField.backgroundColor = [UIColor greenColor];    [self.view addSubview:_textField];}

4，在SecondViewController.m中實現發送通知方法

- (void)postNotification {    NSDictionary *dict = [[NSDictionary alloc] initWithObjectsAndKeys:_textField.text,@"test" ,nil];    //建立通知    NSNotification *notification =[NSNotification notificationWithName:@"getValue" object:nil userInfo:dict];    //通過通知中樞發送通知    [[NSNotificationCenter defaultCenter] postNotification:notification];    [self dismissViewControllerAnimated:YES completion:nil];}

5，在ViewController.m中註冊通知，並且實現註冊通知方法

#import "ViewController.h"#import "SecondViewController.h"@interface ViewController (){    UILabel *_label;}@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    //添加UIButton，用於跳轉到SecondViewController    UIButton *btn = [[UIButton alloc] initWithFrame:CGRectMake(20, 200, 300, 44)];    [btn setTitle:@"ToSecondViewController" forState:UIControlStateNormal];    btn.backgroundColor = [UIColor grayColor];    [btn addTarget:self action:@selector(toSecondViewController) forControlEvents:UIControlEventTouchUpInside];    [self.view addSubview:btn];        //添加UILabel，用於顯示SecondViewController傳過來的值    _label = [[UILabel alloc] initWithFrame:CGRectMake(20, 100, 300, 44)];    _label.backgroundColor = [UIColor yellowColor];    [self.view addSubview:_label];            //註冊通知    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(getNotification:) name:@"getValue" object:nil];    }- (void)toSecondViewController {    SecondViewController *second = [[SecondViewController alloc] init];    [self presentViewController:second animated:YES completion:nil];}//實現註冊通知方法，給label賦值-(void)getNotification:(NSNotification*)notification{    NSDictionary *dict = [notification userInfo];    _label.text = [dict objectForKey:@"test"];    }@end

源碼地址:https://github.com/rokistar/PassValueUsingNotification

 

iOS傳值－NSNotification