iOS中多视图的传值属性传值和代理传值

Posted 2020-06-23

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首先创建两个类，FirstViewController和SecondViewController，都继承于UIViewController

 1 #import "AppDelegate.h"
 2 #import "FirstViewController.h"
 3 
 4 @interface AppDelegate ()
 5 
 6 @end
 7 
 8 @implementation AppDelegate
 9 
10 
11 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
12     //初始化视图控制器
13     FirstViewController *firstVc=[[FirstViewController alloc]init];
14     //设置根视图控制器
15     self.window.rootViewController=firstVc;
16     return YES;
17 }

1 #import <UIKit/UIKit.h>
2 #import "SecondViewController.h"
3 @interface FirstViewController : UIViewController<UITextFieldDelegate,posVlueDelegate>
4 @property(strong,nonatomic) UITextField *textName;
5 @end

 1 #import "FirstViewController.h"
 2 
 3 @interface FirstViewController ()
 4 
 5 @end
 6 
 7 @implementation FirstViewController
 8 
 9 - (void)viewDidLoad {
10     [super viewDidLoad];
11     //设置背景视图的颜色
12     self.view.backgroundColor=[UIColor redColor];
13     //初始化
14     self.textName=[[UITextField alloc] initWithFrame:CGRectMake(100, 150, 200, 40)];
15     //设置文本框的颜色
16     self.textName.backgroundColor=[UIColor whiteColor];
17     self.textName.borderStyle=1;
18     [self.view addSubview:self.textName];
19     
20 }
21 -(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
22 {
23     SecondViewController *secondVc=[[SecondViewController alloc] init];
24     //设置属性值 即 传值给SecondViewController
25     secondVc.str=self.textName.text;
26     //进入第二页
27     [self presentViewController:secondVc animated:YES completion:^{
28         NSLog(@"FirstViewController切换到SecondViewController");
29     }];
30     //指定代理
31     secondVc.delegate=self;
32 }
33 //实现协议方法
34 -(void)posVlue:(NSString *)str
35 {
36     self.textName.text=str;
37 }
38 
39 
40 
41 
42 
43 
44 
45 - (void)didReceiveMemoryWarning {
46     [super didReceiveMemoryWarning];
47     // Dispose of any resources that can be recreated.
48 }

 1 #import <UIKit/UIKit.h>
 2 //创建协议
 3 @protocol posVlueDelegate<NSObject>
 4 -(void)posVlue:(NSString *)str;//协议方法
 5 
 6 @end
 7 
 8 @interface SecondViewController : UIViewController
 9 @property(strong,nonatomic)UITextField *textName;
10 @property(strong,nonatomic)NSString *str;
11 //创建协议类型的属性
12 @property(assign,nonatomic)id<posVlueDelegate>delegate;
13 @end

 1 #import "SecondViewController.h"
 2 
 3 @interface SecondViewController ()
 4 
 5 @end
 6 
 7 @implementation SecondViewController
 8 
 9 - (void)viewDidLoad {
10     [super viewDidLoad];
11     self.view.backgroundColor=[UIColor grayColor];
12     self.textName=[[UITextField alloc] initWithFrame:CGRectMake(100, 150, 200, 50)];
13     self.textName.backgroundColor=[UIColor whiteColor];
14     self.textName.borderStyle=1;
15     [self.view addSubview:self.textName];
16     //接受FirstViewController传过来的值
17     self.textName.text=self.str;
18 }
19 -(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
20 {
21     [self dismissViewControllerAnimated:YES completion:^{
22         NSLog(@"SecondViewController切换到FirstViewController");
23     }];
24     
25     if (self.delegate) {
26         [self.delegate posVlue:self.textName.text];
27     }
28 }
29 
30 
31 - (void)didReceiveMemoryWarning {
32     [super didReceiveMemoryWarning];
33     // Dispose of any resources that can be recreated.
34 }