UI基础 属性代理传值

rootview.h

#import <UIKit/UIKit.h>

NS_ASSUME_NONNULL_BEGIN

@interface RootViewController : UIViewController

@end

rootview.m

#import "RootViewController.h"
#import "SecondViewController.h"
@interface RootViewController ()<ChuanZhiDelegate>
{
    UITextField *tf;
    
}
@end

@implementation RootViewController

- (void)viewDidLoad {
    [super viewDidLoad];
//    UIView *view=[[UIView alloc] initWithFrame:CGRectMake(0, 0, 100, 100)];
//
//    view.backgroundColor=[UIColor redColor];
//    [self.view addSubview:view];
//

    //把控制导航栏内容代码写到对应的页面上来
    self.navigationItem.title=@"首页";
    
//    self.navigationItem.titleView=
    //左右侧的按钮 文字
//    self.navigationItem.rightBarButtonItem=[[UIBarButtonItem alloc] initWithTitle:@"右侧" style:UIBarButtonItemStylePlain target:self action:@selector(touchRight)];
// 图片
    self.navigationItem.rightBarButtonItem=[[UIBarButtonItem alloc]initWithImage:[UIImage imageNamed:@"Processsettings"] style:UIBarButtonItemStylePlain target:self action:@selector(touchRight)];
    
// 第一个页面中的输入框 页面填充框
    tf =[[UITextField alloc]initWithFrame:CGRectMake(20, 200, 280, 40)];
    tf.backgroundColor=[UIColor greenColor];
    [self.view addSubview:tf];
    
    

    
}


-(void)Chaunzhi:(NSString *)str
{
    
    NSLog(@"验证有没有传值成功%@",str);
    
}

-(void)touchRight
{
    NSLog(@"右侧");
    
    SecondViewController *second =[[SecondViewController alloc]init];
    
    //传值
    second.inpurStr=tf.text;
    
    second.delegate=self;
    
    
    
    //跳转
    [self.navigationController pushViewController:second animated:YES];
    
    
}
@end

secondview.h

#import <UIKit/UIKit.h>


//1.协议的名称 声明协议
@protocol ChuanZhiDelegate <NSObject>

-(void)Chaunzhi:(NSString *)str;

@end

NS_ASSUME_NONNULL_BEGIN

@interface SecondViewController : UIViewController

//声明一个属性用来接收传递过来的值
@property(nonatomic,strong)NSString *inpurStr;

//第二步 声明属性 （代理人）
@property(nonatomic,assign)id<ChuanZhiDelegate>delegate;


@end

secondview.m

#import "SecondViewController.h"

@interface SecondViewController ()

@end

@implementation SecondViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor =[UIColor greenColor];
    
//    第二个页面左上角返回按钮
    self.navigationItem.leftBarButtonItem=[[UIBarButtonItem alloc]initWithImage:[UIImage imageNamed:@"fanhui"] style:UIBarButtonItemStylePlain target:self action:@selector(goBack)];
    
    //第二个页面中的label
    UILabel* label=[[UILabel alloc]initWithFrame:CGRectMake(20, 200, 280, 40)];
    label.backgroundColor=[UIColor greenColor];
    
    label.text=self.inpurStr;
    
    [self.view addSubview:label];
}

-(void)goBack
{
    //返回的时候触发方法 将值传递回去
    [self.delegate Chaunzhi:@"这个是要返回的值"];
    
//    从哪里回到上一个
    [self.navigationController popToRootViewControllerAnimated:YES];
    
}

@end