ios 多种传值方式

在网上看了看传值方法,没有找到完整的.在这把自己看到的几种传值方法写写吧.

1 . 属性传值

2 . 通知传值

3 . 代理传值

4 . block传值

5 . 单列传值

6 . ShareApplication

7 . NSUserdefault

1 . 属性传值

我个人理解就是在页面发生跳转的时候把本页面的值传递到目标页面.

2 . 通知传值

在A页面发布通知,在需要数据的页面监听A所发布的通知, 监听结束,移除监听.

3 代理传值

自己对这个不是很了解

RootViewControllers页面push到DetailViewControllers页面，如果DetailViewControllers页面的信息想回传（回调）到RootViewControllers页面，用代理传值，其中DetailViewControllers定义协议和声明代理，RootViewControllers确认并实现代理，RootViewControllers作为DetailViewControllers的代理

首先在DetailViewControllers.h文件中我们创建协议方法

在DetailViewControllers的.m中我们判定代理对象存在时，为其绑定相应方法

RootViewControllers的.m文件中我们指定代理并让其执行代理的方法

4.block传值

Blocks可以作为函数参数或者函数的返回值，而其本身又可以带输入参数或返回值。

5 . 单列传值

AppStatus.h  创建一个单例类 AppStatus

 1 #import <Foundation/Foundation.h>
 2
 3 @interface AppStatus : NSObject
 4 {
 5     NSString *_contextStr;
 6 }
 7
 8 @property(nonatomic,retain)NSString *contextStr;
 9
10 +(AppStatus *)shareInstance;
11
12 @end

AppStatus.m

1 #import "AppStatus.h"
 2
 3 @implementation AppStatus
 4
 5 @synthesize contextStr = _contextStr;
 6
 7 static AppStatus *_instance = nil;
 8
 9 +(AppStatus *)shareInstance
10 {
11     if (_instance == nil)
12     {
13         _instance = [[super alloc]init];
14     }
15     return _instance;
16 }
17
18 -(id)init
19 {
20     if (self = [super init])
21     {
22
23     }
24     return self;
25 }
26
27 -(void)dealloc
28 {
29     [super dealloc];
30 }
31
32 @end

RootViewController.h

1 #import "RootViewController.h"
 2 #import "DetailViewController.h"
 3 #import "AppStatus.h"
 4
 5 @interface RootViewController ()
 6
 7 @end
 8
 9 @implementation RootViewController
10
11 -(void)loadView
12 {
13     //核心代码
14     UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
15     btn.frame = CGRectMake(0, 0, 100, 30);
16     [btn setTitle:@"Push" forState:0];
17     [btn addTarget:self action:@selector(pushAction:) forControlEvents:UIControlEventTouchUpInside];
18     [self.view addSubview:btn];
19 }
20
21 -(void)pushAction:(id)sender
22 {
23     tf = (UITextField *)[self.view viewWithTag:1000];
24
25  //单例传值  将要传递的信息存入单例中（共享中）
26   //  [[AppStatus shareInstance]setContextStr:tf.text]; 跟下面这种写法是等价的
27     [AppStatus shareInstance].contextStr = tf.text;
28     //导航push到下一个页面
29     //pushViewController 入栈引用计数+1，且控制权归系统
30     DetailViewController *detailViewController = [[DetailViewController alloc]init];
31
32     //导航push到下一个页面
33     [self.navigationController pushViewController:detailViewController animated:YES];
34     [detailViewController release];
35 }
36
37 @end

DetailViewController.h

1 #import <UIKit/UIKit.h>
2 @protocol ChangeDelegate;//通知编译器有此代理
3
4 @interface DetailViewController : UIViewController
5 {
6     UITextField *textField;
7 }
8
9 @end

DetailViewController.m

 1 #import "DetailViewController.h"
 2 #import "AppStatus.h"
 3
 4 @interface DetailViewController ()
 5
 6 @end
 7
 8 @implementation DetailViewController
 9
10 @synthesize naviTitle = _naviTitle;
11
12 -(void)loadView
13 {
14     self.view = [[[UIView alloc]initWithFrame:CGRectMake(0, 0, 320, 480)]autorelease];
15
16     //单例
17     self.title = [AppStatus shareInstance].contextStr;
18     textField = [[UITextField alloc]initWithFrame:CGRectMake(100, 100, 150, 30)];
19     textField.borderStyle = UITextBorderStyleLine;
20     [self.view addSubview:textField];
21     [textField release];
22
23     UIBarButtonItem *doneItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDonetarget:self action:@selector(doneAction:)];
24     self.navigationItem.rightBarButtonItem = doneItem;
25     [doneItem release];
26 }
27
28 //这个方法是执行多遍的  相当于刷新view
29 -(void)viewWillAppear:(BOOL)animated
30 {
31     [super viewWillAppear:animated];
32     tf = (UITextField *)[self.view viewWithTag:1000];
33     tf.text = [AppStatus shareInstance].contextStr;
34 }
35
36 //pop回前一个页面
37 -(void)doneAction:(id)sender
38 {
39     //单例传值
40     [AppStatus shareInstance].contextStr = textField.text;
41     [self.navigationController popToRootViewControllerAnimated:YES];
42 } 

6 .ShareApplication

对于这种传值方式不怎么理解

7.NSUserdefault

我自己的NSUserdefault的理解就是用本数据暂时存储到本地,然后在其他页面需要的时候在获取.