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
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.
}
1.
//RootViewController.m
2.
-(
void
)showName:(NSString *)nameString{
3.
self.nameLabel.text = nameString;
4.
}
(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