iOS UI-界面传值（三种方法）

#import <Foundation/Foundation.h>

@interface DataModel : NSObject

@property (nonatomic, copy) NSString *name;
@property (nonatomic, copy) NSString *address;

@end

#import "DataModel.h"

@implementation DataModel

@end

#import <UIKit/UIKit.h>
@class DataModel;
//设置协议
@protocol PassValueDelegate <NSObject>
- (void) passValueFromFirstVCToSecondVC:(DataModel *) dataModel;
@end

@interface FirstViewController : UIViewController
//设置代理
@property (nonatomic, strong) id<PassValueDelegate> delegate;
//设置通知传值接受者
@property (nonatomic, strong) DataModel *firstNOtificationModel;
//设置代理传值传值者
@property (nonatomic, strong) DataModel *firstDelegateModel;

@end


#import "FirstViewController.h"
#import "DataModel.h"
#import "SecondViewController.h"


@interface FirstViewController ()
//设置接收通知传值的标签
@property (nonatomic, strong)UILabel *label;
//设置接收block传值的标签
@property (nonatomic, strong)UILabel *lblBlock;

@end

@implementation FirstViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    [self.view setBackgroundColor:[UIColor orangeColor]];
    
    [self createButtonAndLabel];
    
    //创建观察者
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(receiveValue:) name:@"passValueFromSecondVCToFirstVC" object:nil];
}


#pragma mark - 创建按钮和标签
- (void)createButtonAndLabel
{
    //创建标签
    self.label = [[UILabel alloc] initWithFrame:CGRectMake(10, 200, 355, 60)];
    [self.label setBackgroundColor:[UIColor redColor]];
    self.label.textAlignment = NSTextAlignmentCenter;
    [self.view addSubview:self.label];
    
    //创建标签
    self.lblBlock = [[UILabel alloc] initWithFrame:CGRectMake(10, 420, 355, 60)];
    [self.lblBlock setBackgroundColor:[UIColor redColor]];
    self.lblBlock.textAlignment = NSTextAlignmentCenter;
    [self.view addSubview:self.lblBlock];

    //创建按钮
    UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
    [btn setFrame:CGRectMake(80, 300, 215, 80)];
    [btn setBackgroundColor:[UIColor blackColor]];
    [btn setTitle:@"goToNextView" forState:UIControlStateNormal];
    [btn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
    [btn addTarget:self action:@selector(goToNextView) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:btn];
}

#pragma mark - 观察者接收值关联方法
- (void)receiveValue:(NSNotification *)notification
{
    if ([notification.object isKindOfClass:[DataModel class]]) {
        self.firstNOtificationModel = notification.object;
        self.label.text = [NSString stringWithFormat:@"name:%@ address:%@",self.firstNOtificationModel.name,self.firstNOtificationModel.address];
    }
}
#pragma mark - 代理传值、block接收值
//按钮关联方法
- (void)goToNextView
{
    SecondViewController *secondVC = [[SecondViewController alloc] init];
    [self presentViewController:secondVC animated:YES completion:nil];
    
    [secondVC setBlock:^(DataModel *dataModel){
        self.lblBlock.text = [NSString stringWithFormat:@"name:%@ address:%@",dataModel.name,dataModel.address];
    }];
    
    self.delegate = secondVC;
    if ([self.delegate respondsToSelector:@selector(passValueFromFirstVCToSecondVC:)]) {
        [self.delegate performSelector:@selector(passValueFromFirstVCToSecondVC:) withObject:self.firstDelegateModel];
    }
}

#pragma mark - 懒加载
- (DataModel *)firstDelegateModel
{
    if (!_firstDelegateModel) {
        _firstDelegateModel = [[DataModel alloc] init];
        _firstDelegateModel.name = @"GuYu";
        _firstDelegateModel.address = @"AnHui";
    }
    return _firstDelegateModel;
}

@end

#import <UIKit/UIKit.h>
#import "FirstViewController.h"
@class DataModel;
//定义block类型
typedef void(^Block)(DataModel *dataModel);

@interface SecondViewController : UIViewController <PassValueDelegate>
//通知传值的传值者
@property (nonatomic, strong) DataModel *secondNotificationModel;
//代理传值的接受者
@property (nonatomic, strong) DataModel *secondDelegateModel;
//block的接受者
@property (nonatomic, strong) Block block;

@end


#import "SecondViewController.h"
#import "DataModel.h"

@interface SecondViewController ()

@property (strong, nonatomic) UILabel *label;

@end

@implementation SecondViewController
- (void)viewDidLoad {
    [super viewDidLoad];
    [self.view setBackgroundColor:[UIColor groupTableViewBackgroundColor]];
    
    [self createButtonAndLabel];
}
#pragma mark - 创建标签和按钮
- (void)createButtonAndLabel
{
    //创建标签
    self.label = [[UILabel alloc] initWithFrame:CGRectMake(10, 200, 355, 60)];
    [self.label setBackgroundColor:[UIColor redColor]];
    self.label.textAlignment = NSTextAlignmentCenter;
    [self.view addSubview:self.label];

    //创建按钮
    UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
    [btn setFrame:CGRectMake(80, 300, 215, 80)];
    [btn setBackgroundColor:[UIColor blackColor]];
    [btn setTitle:@"goToBack" forState:UIControlStateNormal];
    [btn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
    [btn addTarget:self action:@selector(goToBack) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:btn];
    
}
#pragma mark - block传值、通知传值
//按钮关联方法
- (void)goToBack
{
    [self dismissViewControllerAnimated:YES completion:nil];
    
    //block传值
    self.block(self.secondNotificationModel);
    
    //通知传值
    [[NSNotificationCenter defaultCenter] postNotificationName:@"passValueFromSecondVCToFirstVC" object:self.secondNotificationModel];
}

#pragma mark - 代理协议方法
- (void)passValueFromFirstVCToSecondVC:(DataModel *)dataModel
{
    self.secondDelegateModel = dataModel;
    self.label.text = [NSString stringWithFormat:@"name:%@ address:%@",self.secondDelegateModel.name,self.secondDelegateModel.address];
}

#pragma mark - 懒加载
//初始化_secondNotificationModel
- (DataModel *)secondNotificationModel
{
    if (!_secondNotificationModel) {
        _secondNotificationModel = [[DataModel alloc] init];
        _secondNotificationModel.name = @"Bowen";
        _secondNotificationModel.address = @"China";
    }
    return _secondNotificationModel;
}
//初始化self.block
- (void)setBlock:(Block)block
{
    _block = block;
}


@end