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

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

作者:wangtao169447  发布日期:2014-07-18 19:06:24
Tag标签:页面  方式  
  • 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

    \ 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

    \ 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:

    \

    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

    \

    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 

 
posted @ 2015-03-11 21:38  mengxiangtong22  阅读(415)  评论(0编辑  收藏  举报