iOS中多视图的传值 属性传值和代理传值

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 }

总结：

1.页面之间传值方式

属性传值

适用于 正向传值

1.1 在要显示信息的页面创建属性

1.2 在要传值的页面 设置属性值

1.3 在显示页面的viewDidLoad方法中，接受属性值

代理传值

适用于反向传值

1.创建协议及协议方法，在反向传值的页面SecondViewController中

2.创建协议类型的属性，在SecondViewController中创建属性

@property(assign,nonatomic) id<posVlueDelegate> delegate;

3.调用属性即 delegate

SecondViewController页面中 对象传值的方法中调用

if (self.delegate) {

[self.delegate posVlue:self.textName.text];

}

4.在第一页 即显示修改富哦信息的页面

遵循协议 实现协议方法 指定代理对象（即 在页面传递参数的方法中为代理赋值-(void)posVlue:(NSString *)str

{

self.textField.text=str;

}）