iOS页面间传值的方式（Delegate/NSNotification/Block/NSUserDefault）

iOS页面间传值的方式（NSUserDefault/Delegate/NSNotification/Block）

实现了以下iOS页面间传值：1.委托delegate方式；2.通知notification方式；3.block方式；4.UserDefault或者文件方式；5.单例模式方式；6.通过设置属性，实现页面间传值

在iOS开发中，我们经常会遇到页面间跳转传值的问题，现归纳总结一下：

情况1：A页面跳转到B页面

方法：

在B页面的控制器中，编写对应的属性，在A页面跳转到B页面的地方，给B的属性赋值即可

1

@property(nonatomic) NSInteger flag;//当前系统标示（0：其他传值方式；1：<span id="13_nwp" style="width: auto; height: auto; float: none;"><a id="13_nwl" href="http://cpro.baidu.com/cpro/ui/uijs.php?c=news&cf=1001&ch=0&di=128&fv=16&jk=ca181de9ee49d360&k=block&k0=block&kdi0=0&luki=5&n=10&p=baidu&q=00007110_cpr&rb=0&rs=1&seller_id=1&sid=60d349eee91d18ca&ssp2=1&stid=0&t=tpclicked3_hc&tu=u1704338&u=http%3A%2F%2Fwww%2Edaxueit%2Ecom%2Farticle%2F4452%2Ehtml&urlid=0" target="_blank" mpid="13" style="text-decoration: none;"><span style="color:#0000ff;font-size:14px;width:auto;height:auto;float:none;">block</span></a></span>传值方式）

在A页面的试图控制器中

1

2

3

4

5

6

- (IBAction)showSecondView:(id)sender {

    SecondViewController *second = [[SecondViewController alloc] initWithNibName:@"SecondViewController"bundle:nil];

    second.delegate = self;

    second.<span id="11_nwp"style="width: auto; height: auto; float: none;"><a id="11_nwl"href="http://cpro.baidu.com/cpro/ui/uijs.php?c=news&cf=1001&ch=0&di=128&fv=16&jk=ca181de9ee49d360&k=flag&k0=flag&kdi0=0&luki=2&n=10&p=baidu&q=00007110_cpr&rb=0&rs=1&seller_id=1&sid=60d349eee91d18ca&ssp2=1&stid=0&t=tpclicked3_hc&tu=u1704338&u=http%3A%2F%2Fwww%2Edaxueit%2Ecom%2Farticle%2F4452%2Ehtml&urlid=0"target="_blank"mpid="11"style="text-decoration: none;"><span style="color:#0000ff;font-size:14px;width:auto;height:auto;float:none;">flag</span></a></span> = 0;

    [self presentViewController:second animated:YES completion:nil];

}

情况2：A页面跳转到B页面，B页面再跳转回A页面

主流方案：

（1）通过委托delegate的方式实现

设置协议及方法

1

 

1

//SecondViewController.h

1

2

3

@protocol secondViewDelegate

-(void)showName:(NSString *)nameString;

@end

设置代理(为防止循环引用，此次采用了weak)

1

 

1

//SecondViewController.h

1

2

3

4

@interface SecondViewController : UIViewController

@property (nonatomic, weak)id<secondViewDelegate> delegate;

@property (nonatomic, copy) a<span id="0_nwp"style="width: auto; height: auto; float: none;"><a id="0_nwl"href="http://cpro.baidu.com/cpro/ui/uijs.php?c=news&cf=1001&ch=0&di=128&fv=16&jk=ca181de9ee49d360&k=block&k0=block&kdi0=0&luki=5&n=10&p=baidu&q=00007110_cpr&rb=0&rs=1&seller_id=1&sid=60d349eee91d18ca&ssp2=1&stid=0&t=tpclicked3_hc&tu=u1704338&u=http%3A%2F%2Fwww%2Edaxueit%2Ecom%2Farticle%2F4452%2Ehtml&urlid=0"target="_blank"mpid="0"style="text-decoration: none;"><span style="color:#0000ff;font-size:14px;width:auto;height:auto;float:none;">block</span></a></span> block;

@end

点击按钮传递数组让其显示

1

2

3

4

5

6

7

8

9

//SecondViewController.m

- (IBAction)delegateMethod:(id)sender {

    if([self notEmpty]) {

        [self.delegate showName:self.nameTextField.text];

        [self dismissViewControllerAnimated:YES completion:nil];

    }else{

        [self showAlert];

    }

}

调用，显示

1

2

3

4

//RootViewController.m

-(void)showName:(NSString *)nameString{

    self.nameLabel.text = nameString;

}

最重要也是最容易忽略的，就是一定要设置delegate的指向。

效果：

（2）通过通知notification的方式实现

在B页面的控制器中，发送通知：

1

2

3

4

5

6

7

8

9

//SecondViewController.m

- (IBAction)notificationMethod:(id)sender {

    if([self notEmpty]) {

        [[NSNotificationCenter defaultCenter] postNotificationName:@"ChangeNameNotification"object:self userInfo:@{@"name":self.nameTextField.text}];

        [self dismissViewControllerAnimated:YES completion:nil];

    }else{

        [self showAlert];

    }

}

在A页面的控制器中，注册通知：

1

2

3

4

5

6

7

//RootViewController.m

- (void)viewDidLoad

{

    [super viewDidLoad];

    // Do any additional setup after loading the view from its nib.

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(ChangeNameNotification:) name:@"ChangeNameNotification"object:nil];

}

当我们不使用时，要记得删掉通知：

1

2

3

4

//RootViewController.m

-(void)dealloc{

    [[NSNotificationCenter defaultCenter] removeObserver:self];

}

调用，显示

1

2

3

4

5

6

//RootViewController.m

 

-(void)ChangeNameNotification:(NSNotification*)notification{

    NSDictionary *nameDictionary = [notification userInfo];

    self.nameLabel.text = [nameDictionary objectForKey:@"name"];

}

（3）block方式实现

分析：

在B试图控制器中，定义一个block，参数为字符串

1

2

//SecondViewController.h

typedefvoid (^ablock)(NSString *str);

1

2

3

//SecondViewController.h

 

@property (nonatomic, copy) ablock block;

在B试图控制器中，

1

2

3

4

5

6

7

8

9

10

- (IBAction)blockMethod:(id)sender {

    if([self notEmpty]) {

        if(self.block) {

            self.block(self.nameTextField.text);

            [self dismissViewControllerAnimated:YES completion:nil];

        }

    }else{

        [self showAlert];

    }

}

在A试图显示，回调block

1

2

3

4

5

6

7

- (IBAction)showSecondWithBlock:(id)sender {

    SecondViewController *second = [[SecondViewController alloc] initWithNibName:@"SecondViewController"bundle:nil];

    [self presentViewController:second animated:YES completion:nil];

    second.block = ^(NSString *str){

        self.nameLabel.text = str;

    };

}

链接一篇描述block回调挺有意思的文章：http://blog.csdn.net/mobanchengshuang/article/details/11751671

在查阅资料的过程中，我还看到了以下几种方案：

（1）使用SharedApplication,定义一个变量来传递（感觉和单例的方式一样）

（2）使用文件，或者NSUserdefault来传递

1

2

3

4

5

6

7

8

9

//通过文件或者UserDefault方式存值(感觉不太适合此类传值，如果要用文件或者UserDefault方式存值的话，可以考虑此方式)

- (IBAction)userDefaultMethod:(id)sender {

    if([self notEmpty]) {

        [[NSUserDefaults standardUserDefaults] setObject:self.nameTextField.text forKey:@"myNameText"];

        [self dismissViewControllerAnimated:YES completion:nil];

    }else{

        [self showAlert];

    }

}

在A试图控制器显示

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

-(void)viewDidAppear:(BOOL)animated{

    [super viewDidAppear:animated];

    //如果想测试通过UserDefault方式传值或者通过单例方式传值，取消以下注释即可

/*

    if ([[[NSUserDefaults standardUserDefaults] objectForKey:@"myNameText"] length] != 0) {

        self.nameLabel.text = [[NSUserDefaults standardUserDefaults] objectForKey:@"myNameText"];

        [[NSUserDefaults standardUserDefaults] setObject:@"" forKey:@"myNameText"];

    }

    DataSource *<span id="4_nwp" style="width: auto; height: auto; float: none;"><a id="4_nwl" href="http://cpro.baidu.com/cpro/ui/uijs.php?c=news&cf=1001&ch=0&di=128&fv=16&jk=ca181de9ee49d360&k=data&k0=data&kdi0=0&luki=4&n=10&p=baidu&q=00007110_cpr&rb=0&rs=1&seller_id=1&sid=60d349eee91d18ca&ssp2=1&stid=0&t=tpclicked3_hc&tu=u1704338&u=http%3A%2F%2Fwww%2Edaxueit%2Ecom%2Farticle%2F4452%2Ehtml&urlid=0" target="_blank" mpid="4" style="text-decoration: none;"><span style="color:#0000ff;font-size:14px;width:auto;height:auto;float:none;">data</span></a></span>Source = [DataSource sharedDataSource];

    if ([dataSource.myName length] != 0) {

        self.nameLabel.text = dataSource.myName;

        dataSource.myName = @"";

    }

*/

}

（3）通过一个单例的class来传递

B试图控制器

1

2

3

4

5

6

7

8

9

10

//通过单例方式传值(感觉不太适合此类传值，如果要用单例方式传值的话，可以考虑此方式)

- (IBAction)singletonMethod:(id)sender {

    if([self notEmpty]) {

        DataSource *dataSource = [DataSource sharedDataSource];

        dataSource.myName = self.nameTextField.text;

        [self dismissViewControllerAnimated:YES completion:nil];

    }else{

        [self showAlert];

    }

}

A试图控制器显示

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

-(void)viewDidAppear:(BOOL)animated{

    [super viewDidAppear:animated];

    //如果想测试通过UserDefault方式传值或者通过单例方式传值，取消以下注释即可

/*

    if ([[[NSUserDefaults standardUserDefaults] objectForKey:@"myNameText"] length] != 0) {

        self.nameLabel.text = [[NSUserDefaults standardUserDefaults] objectForKey:@"myNameText"];

        [[NSUserDefaults standardUserDefaults] setObject:@"" forKey:@"myNameText"];

    }

    DataSource *<span id="2_nwp" style="width: auto; height: auto; float: none;"><a id="2_nwl" href="http://cpro.baidu.com/cpro/ui/uijs.php?c=news&cf=1001&ch=0&di=128&fv=16&jk=ca181de9ee49d360&k=data&k0=data&kdi0=0&luki=4&n=10&p=baidu&q=00007110_cpr&rb=0&rs=1&seller_id=1&sid=60d349eee91d18ca&ssp2=1&stid=0&t=tpclicked3_hc&tu=u1704338&u=http%3A%2F%2Fwww%2Edaxueit%2Ecom%2Farticle%2F4452%2Ehtml&urlid=0" target="_blank" mpid="2" style="text-decoration: none;"><span style="color:#0000ff;font-size:14px;width:auto;height:auto;float:none;">data</span></a></span>Source = [DataSource sharedDataSource];

    if ([dataSource.myName length] != 0) {

        self.nameLabel.text = dataSource.myName;

        dataSource.myName = @"";

    }

*/

}

@end

这里面用到了单例模式，编写了DataSource这个类，存放数据

1

2

3

4

5

6

7

8

9

10

11

12

13

14

//

//  DataSource.h

//  TestCallBack

//

//  Created by csdc-iMac on 14-7-17.

//  Copyright (c) 2014年 JuneWang. All rights reserved.

//

 

#import <Foundation/Foundation.h>

 

@interface DataSource : NSObject

@property (nonatomic, strong) NSString *myName;

+(DataSource*)sharedDataSource;

@end

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

//

//  DataSource.m

//  TestCallBack

//

//  Created by csdc-iMac on 14-7-17.

//  Copyright (c) 2014年 JuneWang. All rights reserved.

//

 

#import "DataSource.h"

 

@implementation DataSource

+(DataSource *)sharedDataSource{

    staticDataSource *<span id="1_nwp"style="width: auto; height: auto; float: none;"><a id="1_nwl"href="http://cpro.baidu.com/cpro/ui/uijs.php?c=news&cf=1001&ch=0&di=128&fv=16&jk=ca181de9ee49d360&k=data&k0=data&kdi0=0&luki=4&n=10&p=baidu&q=00007110_cpr&rb=0&rs=1&seller_id=1&sid=60d349eee91d18ca&ssp2=1&stid=0&t=tpclicked3_hc&tu=u1704338&u=http%3A%2F%2Fwww%2Edaxueit%2Ecom%2Farticle%2F4452%2Ehtml&urlid=0"target="_blank"mpid="1"style="text-decoration: none;"><span style="color:#0000ff;font-size:14px;width:auto;height:auto;float:none;">data</span></a></span>Source = nil;

    staticdispatch_once_t once;

    dispatch_once(&once, ^{

        dataSource = [DataSource new];

    });

    returndataSource;

}

@end

程序运行截图

A视图：

B视图

当输入姓名，并点击对应的确认按钮后，会回到A视图，并显示在B视图中输入的姓名