iOS页面间传值的五种方式总结(Delegate/NSNotification/Block/NSUserDefault/单例)

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

      1.//SecondViewController.h
      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

      1.//RootViewController.m
      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页面间传值的五种方式总结(Delegate/NSNotification/Block/NSUserDefault/单例) 设置协议及方法

      1. 
      1.//SecondViewController.h
      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)

      1. 
      1.//SecondViewController.h
      1.@interface SecondViewController : UIViewController
      2.@property (nonatomic, weak)id<secondViewDelegate> delegate;
      3.@property (nonatomic, copy) ablock block;
      4.@end

      调用

      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

      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页面间传值的五种方式总结(Delegate/NSNotification/Block/NSUserDefault/单例) 在B页面的控制器中,发送通知:

      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:

      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:

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

      调用,显示

      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

      1.//SecondViewController.h
      2.typedef void (^ablock)(NSString *str);
      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

      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

      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

      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

      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

      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

      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

      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 
      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页面间传值的五种方式总结(Delegate/NSNotification/Block/NSUserDefault/单例)

      B视图

      iOS页面间传值的五种方式总结(Delegate/NSNotification/Block/NSUserDefault/单例)

      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页面间传值的五种方式总结(Delegate/NSNotification/Block/NSUserDefault/单例)

      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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