iOS页面间传值的方式(NSUserDefault/Delegate/NSNotification/Block/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
//SecondViewController.h
@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
//RootViewController.m
- (IBAction)showSecondView:(id)sender { SecondViewController *second = [[SecondViewController alloc] initWithNibName:@"SecondViewController" bundle:nil]; second.delegate = self; second.flag = 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
//SecondViewController.h
@interface SecondViewController : UIViewController @property (nonatomic, weak)id<secondViewDelegate> delegate; @property (nonatomic, copy) ablock block; @end
显示
//RootViewController.m
-(void)showName:(NSString *)nameString{ self.nameLabel.text = nameString; }
(2)通过通知notification的方式实现
//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:
//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:
//RootViewController.m -(void)dealloc{ [[NSNotificationCenter defaultCenter] removeObserver:self]; }
调用,显示
//RootViewController.m -(void)ChangeNameNotification:(NSNotification*)notification{ NSDictionary *nameDictionary = [notification userInfo]; self.nameLabel.text = [nameDictionary objectForKey:@"name"]; }
(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
//SecondViewController.h typedef void (^ablock)(NSString *str);
//SecondViewController.h @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
- (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
- (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; }; }
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
//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
-(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 *dataSource = [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
//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
-(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 *dataSource = [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
// // 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
// // 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{ static DataSource *dataSource = nil; static dispatch_once_t once; dispatch_once(&once, ^{ dataSource = [DataSource new]; }); return dataSource; } @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
iOS页面间传值的方式(NSUserDefault/Delegate/NSNotification/Block/单例),,5-wow.com
郑重声明:本站内容如果来自互联网及其他传播媒体,其版权均属原媒体及文章作者所有。转载目的在于传递更多信息及用于网络分享,并不代表本站赞同其观点和对其真实性负责,也不构成任何其他建议。