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];
//

    //把控制導航欄內容程式碼寫到對應的頁面上來
    self.navigationItem.title=@"首頁";
    
//    self.navigationItem.titleView=
    
 
//左右側的按鈕 文字
//    self.navigationItem.rightBarButtonItem=[[UIBarButtonItem alloc] initWithTitle:@"右側" style:UIBarButtonItemStylePlain target:self action:@selector(touchRight)];
// 圖片
    self.navigationItem.rightBarButtonItem=[[UIBarButtonItem alloc]initWithImage:[UIImage imageNamed:@"Processsettings"] style:UIBarButtonItemStylePlain target:self action:@selector(touchRight)];
    
 
// 第一個頁面中的輸入框 頁面填充框
    tf =[[UITextField alloc]initWithFrame:CGRectMake(20, 200, 280, 40)];
    tf.backgroundColor=[UIColor greenColor];
    [self.view addSubview:tf];
    
    

    
}


-(void)Chaunzhi:(NSString *)str
{
    
    NSLog(@"驗證有沒有傳值成功%@",str);
    
}

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

secondview.h

#import <UIKit/UIKit.h>


//1.協議的名稱 宣告協議
@protocol ChuanZhiDelegate <NSObject>

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

@end

NS_ASSUME_NONNULL_BEGIN

@interface SecondViewController : UIViewController

//宣告一個屬性用來接收傳遞過來的值
@property(nonatomic,strong)NSString *inpurStr;

//第二步 宣告屬性 （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];
    
//    第二個頁面左上角返回按鈕
    self.navigationItem.leftBarButtonItem=[[UIBarButtonItem alloc]initWithImage:[UIImage imageNamed:@"fanhui"] style:UIBarButtonItemStylePlain target:self action:@selector(goBack)];
    
    //第二個頁面中的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
{
    //返回的時候觸發方法 將值傳遞回去
    [self.delegate Chaunzhi:@"這個是要返回的值"];
    
//    從哪裡回到上一個
    [self.navigationController popToRootViewControllerAnimated:YES];
    
}

@end