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

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

    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

    view source print ?
    1. //SecondViewController.h
    view source print ?
    1. @property(nonatomic) NSInteger flag;//当前系统标示(0:其他传值方式;1:block传值方式)

    在A页面的试图控制器中

    view source print ?
    1. //RootViewController.m
    view source print ?
    1. - (IBAction)showSecondView:(id)sender {
    2. SecondViewController *second = [[SecondViewController alloc] initWithNibName:@'SecondViewController'bundle:nil];
    3. second.delegate = self;
    4. second.flag = 0;
    5. [self presentViewController:second animated:YES completion:nil];
    6. }

    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

    iOS页面间传值的方式(Delegate/NSNotification/Block/NSUserDefault/单例)_第1张图片 设置协议及方法          
    view source print ?
    1.  
    view source print ?
    1. //SecondViewController.h
    view source print ?
    1. @protocol secondViewDelegate
    2. -(void)showName:(NSString *)nameString;
    3. @end

    设置代理(为防止循环引用,此处采用了weak)

    view source print ?
    1.  
    view source print ?
    1. //SecondViewController.h
    view source print ?
    1. @interface SecondViewController : UIViewController
    2. @property (nonatomic, weak)id<secondViewDelegate> delegate;
    3. @property (nonatomic, copy) ablock block;
    4. @end
       调用
    view source print ?
    01. //SecondViewController.m
    02. - (IBAction)delegateMethod:(id)sender {
    03. if ([self notEmpty]) {
    04. [self.delegate showName:self.nameTextField.text];
    05. [self dismissViewControllerAnimated:YES completion:nil];
    06. }else{
    07. [self showAlert];
    08. }
    09. }

    显示  
    view source print ?
    1. //RootViewController.m
    2. -(void)showName:(NSString *)nameString{
    3. self.nameLabel.text = nameString;
    4. }
    最重要也是最容易忽略的,就是一定要设置delegate的指向。    

    (2)通过通知notification的方式实现

    iOS页面间传值的方式(Delegate/NSNotification/Block/NSUserDefault/单例)_第2张图片 在B页面的控制器中,发送通知:
    view source print ?
    01. //SecondViewController.m
    02. - (IBAction)notificationMethod:(id)sender {
    03. if ([self notEmpty]) {
    04. [[NSNotificationCenter defaultCenter] postNotificationName:@'ChangeNameNotification' object:self userInfo:@{@'name':self.nameTextField.text}];
    05. [self dismissViewControllerAnimated:YES completion:nil];
    06. }else{
    07. [self showAlert];
    08. }
    09. }

    在A页面的控制器中,注册通知:

    view source print ?
    1. //RootViewController.m
    2. - (void)viewDidLoad
    3. {
    4. [super viewDidLoad];
    5. // Do any additional setup after loading the view from its nib.
    6. [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(ChangeNameNotification:) name:@'ChangeNameNotification' object:nil];
    7. }

    当我们不使用时,要记得删掉通知:

    view source print ?
    1. //RootViewController.m
    2. -(void)dealloc{
    3. [[NSNotificationCenter defaultCenter] removeObserver:self];
    4. }

     调用,显示

    view source print ?
    1. //RootViewController.m
    2.  
    3. -(void)ChangeNameNotification:(NSNotification*)notification{
    4. NSDictionary *nameDictionary = [notification userInfo];
    5. self.nameLabel.text = [nameDictionary objectForKey:@'name'];
    6. }

    (3)block方式实现

    block介绍:http://blog.csdn.net/totogo2010/article/details/7839061

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

    分析:

    在B试图控制器中,定义一个block,参数为字符串

    view source print ?
    1. //SecondViewController.h
    2. typedef void (^ablock)(NSString *str);
    view source print ?
    1. //SecondViewController.h
    2.  
    3. @property (nonatomic, copy) ablock block;

    在B试图控制器中,当输入名字,点击对应的确定按钮后

    view source print ?
    01. - (IBAction)blockMethod:(id)sender {
    02. if ([self notEmpty]) {
    03. if (self.block) {
    04. self.block(self.nameTextField.text);
    05. [self dismissViewControllerAnimated:YES completion:nil];
    06. }
    07. }else{
    08. [self showAlert];
    09. }
    10. }

    在A试图显示,回调block

    view source print ?
    1. - (IBAction)showSecondWithBlock:(id)sender {
    2. SecondViewController *second = [[SecondViewController alloc] initWithNibName:@'SecondViewController'bundle:nil];
    3. [self presentViewController:second animated:YES completion:nil];
    4. second.block = ^(NSString *str){
    5. self.nameLabel.text = str;
    6. };
    7. }

    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

    view source print ?
    01. //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)
    02. - (IBAction)userDefaultMethod:(id)sender {
    03. if ([self notEmpty]) {
    04. [[NSUserDefaults standardUserDefaults] setObject:self.nameTextField.text forKey:@'myNameText'];
    05. [self dismissViewControllerAnimated:YES completion:nil];
    06. }else{
    07. [self showAlert];
    08. }
    09. }

    在A试图控制器显示

    view source print ?
    01. -(void)viewDidAppear:(BOOL)animated{
    02. [super viewDidAppear:animated];
    03. //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
    04. /*
    05. if ([[[NSUserDefaults standardUserDefaults] objectForKey:@'myNameText'] length] != 0) {
    06. self.nameLabel.text = [[NSUserDefaults standardUserDefaults] objectForKey:@'myNameText'];
    07. [[NSUserDefaults standardUserDefaults] setObject:@'' forKey:@'myNameText'];
    08. }
    09. DataSource *dataSource = [DataSource sharedDataSource];
    10. if ([dataSource.myName length] != 0) {
    11. self.nameLabel.text = dataSource.myName;
    12. dataSource.myName = @'';
    13. }
    14. */
    15. }

    (3)通过一个单例的class来传递

    B试图控制器

    view source print ?
    01. //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)
    02. - (IBAction)singletonMethod:(id)sender {
    03. if ([self notEmpty]) {
    04. DataSource *dataSource = [DataSource sharedDataSource];
    05. dataSource.myName = self.nameTextField.text;
    06. [self dismissViewControllerAnimated:YES completion:nil];
    07. }else{
    08. [self showAlert];
    09. }
    10. }

    A试图控制器显示

    view source print ?
    01. -(void)viewDidAppear:(BOOL)animated{
    02. [super viewDidAppear:animated];
    03. //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
    04. /*
    05. if ([[[NSUserDefaults standardUserDefaults] objectForKey:@'myNameText'] length] != 0) {
    06. self.nameLabel.text = [[NSUserDefaults standardUserDefaults] objectForKey:@'myNameText'];
    07. [[NSUserDefaults standardUserDefaults] setObject:@'' forKey:@'myNameText'];
    08. }
    09. DataSource *dataSource = [DataSource sharedDataSource];
    10. if ([dataSource.myName length] != 0) {
    11. self.nameLabel.text = dataSource.myName;
    12. dataSource.myName = @'';
    13. }
    14. */
    15. }
    16. @end

    这里面用到了单例模式,编写了DataSource这个类,存放数据

    view source print ?
    01. //
    02. //  DataSource.h
    03. //  TestCallBack
    04. //
    05. //  Created by csdc-iMac on 14-7-17.
    06. //  Copyright (c) 2014年 JuneWang. All rights reserved.
    07. //
    08.  
    09. #import <Foundation/Foundation.h>
    10.  
    11. @interface DataSource : NSObject
    12. @property (nonatomic, strong) NSString *myName;
    13. +(DataSource*)sharedDataSource;
    14. @end 
    view source print ?
    01. //
    02. //  DataSource.m
    03. //  TestCallBack
    04. //
    05. //  Created by csdc-iMac on 14-7-17.
    06. //  Copyright (c) 2014年 JuneWang. All rights reserved.
    07. //
    08.  
    09. #import 'DataSource.h'
    10.  
    11. @implementation DataSource
    12. +(DataSource *)sharedDataSource{
    13. static DataSource *dataSource = nil;
    14. static dispatch_once_t once;
    15. dispatch_once(&once, ^{
    16. dataSource = [DataSource new];
    17. });
    18. return dataSource;
    19. }
    20. @end

    程序运行截图

    A视图:

    iOS页面间传值的方式(Delegate/NSNotification/Block/NSUserDefault/单例)_第3张图片

    B视图

    iOS页面间传值的方式(Delegate/NSNotification/Block/NSUserDefault/单例)_第4张图片

    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

    iOS页面间传值的方式(Delegate/NSNotification/Block/NSUserDefault/单例)_第5张图片

    祝:玩得开心,有什么别的办法或者不正确的地方,欢迎指正。

    如果写得不详细,可以通过源码分析。

     参考:http://blog.csdn.net/cocoarannie/article/details/11857141

    http://www.cnblogs.com/heri/archive/2013/03/18/2965815.html

    源码地址:https://github.com/wangtao169447/PassValue

    出处:http://www.cnblogs.com/JuneWang/p/3850859.html 

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