iOS利用通知逆传值

直接创建两个控制器,点击跳转第二个界面,然后点击按钮进行传值

#import "ViewController.h"

#import "TWOOViewController.h"

@interface ViewController ()

@property(nonatomic,weak)UILabel * label;

@end

@implementation ViewController

- (void)viewDidLoad {

[super viewDidLoad];

UIButton * nextBtn = [[UIButton alloc]initWithFrame:CGRectMake(0, 50, self.view.bounds.size.width, 50)];

nextBtn.backgroundColor = [UIColor redColor];

[nextBtn addTarget:self action:@selector(nextBtnClick:) forControlEvents:UIControlEventTouchUpInside];

[nextBtn setTitle:@"下一个界面" forState:UIControlStateNormal];

[self.view addSubview:nextBtn];

UILabel * labeltext = [[UILabel  alloc]initWithFrame:CGRectMake(0, 150, self.view.bounds.size.width, 50)];

labeltext.backgroundColor = [UIColor yellowColor];

labeltext.textColor = [UIColor greenColor];

[self.view addSubview:labeltext];

self.label = labeltext;

//创建通知

[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(nexttow:) name:@"nextBtnaa" object:nil];

}

-(void)nextBtnClick:(UIButton*)nextBtn{

TWOOViewController * two = [[TWOOViewController alloc]init];

[self presentViewController:two animated:YES completion:nil];

}

-(void)nexttow:(NSNotification*)nontification{

self.label.text = nontification.object;

}

第二个控制器

#import "TWOOViewController.h"

@interface TWOOViewController ()

@end

@implementation TWOOViewController

- (void)viewDidLoad {

[super viewDidLoad];

self.view.backgroundColor = [UIColor blueColor];

UIButton  * backBtn = [[UIButton alloc]initWithFrame:CGRectMake(0, 79, self.view.bounds.size.width, 50)];

[backBtn setTitle:@"回" forState:UIControlStateNormal];

[backBtn addTarget:self action:@selector(backBtnClick:) forControlEvents:UIControlEventTouchUpInside];

[self.view addSubview:backBtn];

}

-(void)backBtnClick:(UIButton*)backBtn{

[[NSNotificationCenter defaultCenter]postNotificationName:@"nextBtnaa" object:@"逆传值"];

//隐藏本控制器

[self dismissViewControllerAnimated:YES completion:nil];

}

结果: