利用代理模式进行页面之间的传值

第一个界面.m文件需要实现

#import "ViewController.h"

#import "seconderViewController.h"

@interface ViewController ()<messageDelegate>

{

    UILabel *lable;

    seconderViewController *sencoderVC;

}

@end

@implementation ViewController

- (void)viewDidLoad {

    [superviewDidLoad];

    [self.viewsetBackgroundColor:[UIColorgreenColor]];

    lable = [UILabelnew];

    lable.backgroundColor = [UIColorgrayColor];

    lable.frame =CGRectMake(10,100, 200,50);

    [self.viewaddSubview:lable];

    

    sencoderVC = [seconderViewControllernew];

    sencoderVC.delegate =self；   

}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{

    sencoderVC = [seconderViewControllernew];

    sencoderVC.delegate =self;

    [selfpresentViewController:sencoderVCanimated:YEScompletion:^{

    }];

}

- (void)messageSender:(NSString *)string{

    lable.text = string;

}

第二个界面.h文件里面

#import <UIKit/UIKit.h>

@protocol messageDelegate <NSObject>

@optional

- (void)messageSender:(NSString *)string;

@end

@interface seconderViewController :UIViewController

@property (nonatomic,weak)id<messageDelegate>delegate;

@end

//第二个界面.m文件

#import "seconderViewController.h"

@interface seconderViewController ()

{

    UILabel *lable;

}

@end

@implementation seconderViewController

- (void)viewDidLoad {

    [superviewDidLoad];

    

    lable = [UILabelnew];

    lable.backgroundColor = [UIColorredColor];

    [lablesetText:@"王维传"];

    lable.frame =CGRectMake(100,100, 200,50);

    [self .viewaddSubview:lable];

}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{

    [self.delegatemessageSender:lable.text];

    [selfdismissViewControllerAnimated:YEScompletion:^{

    }];

}