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

时间:2015-12-29 19:11:04      阅读:299      评论:0      收藏:0      [点我收藏+]

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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

技术分享 设置协议及方法          

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.//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

技术分享 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

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

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原文地址:http://www.cnblogs.com/sunkaifeng/p/5086727.html

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