iOS 两个viewcontroller之间的delegate传值

第二个界面往第一个界面传值

第二个界面

//第二个界面制定协议

@protocol ChuanZhiDelegate <NSObject>

- (void)chuanzhid;

@end

@interface ViewController2 : UIViewController

@property(nonatomic,assign)id<ChuanZhiDelegate>chuanzhidelegate;

@end

- (void)viewDidLoad {

    [super viewDidLoad];

    self.view.backgroundColor=[UIColor cyanColor];

    self.btn=[[UIButton alloc]initWithFrame:CGRectMake(70, 100, 100, 30)];

    self.btn.backgroundColor=[UIColor redColor];

    [self.view addSubview:self.btn];

    [self.btn addTarget:self action:@selector(chuan) forControlEvents:UIControlEventTouchUpInside];

}

- (void)chuan{

    if ([self.chuanzhidelegate respondsToSelector:@selector(chuanzhid)]) {

        [self.chuanzhidelegate chuanzhid];

    }else{

        NSLog(@"代理没有实现changeStatus:方法");

    }

}

然后第一个界面

- (void)viewDidLoad {

    [super viewDidLoad];

    self.btn=[[UIButton alloc]initWithFrame:CGRectMake(70, 100, 100, 30)];

    self.btn.backgroundColor=[UIColor redColor];

    [self.view addSubview:self.btn];

    [self.btn addTarget:self action:@selector(chuanzhi) forControlEvents:UIControlEventTouchUpInside];

    self.view.backgroundColor=[UIColor lightGrayColor];

}

- (void)chuanzhi{

    ViewController2 *vc=[[ViewController2 alloc]init];

    vc.chuanzhidelegate=self;//设置为第二个界面的代理

    [self.navigationController pushViewController:vc animated:YES];

}

//实现协议

- (void)chuanzhid{

    NSLog(@"代理实现");

}