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.
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
- 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**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**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