第二个界面中的lable显示第一个界面textField中的文本
首先我们建立一个RootViewControllers和一个DetailViewControllers，在DetailViewControllers中声明一个textString属性，用于接收传过来的字符串，
同时创建一个Lable用来显示传过的字符串
在RootViewControllers上引入DetailViewControllers同时声明一个textField属性用来输入字符串
然后在RootViewControllers上我们创建并添加一个button，当点击button时响应相应方法进行视图间的切换完成视图间的传值
block传值也是从第二个界面给第一个界面传值
首先我们在DetailViewcontrollers的.h文件中，属性
在RootViewControllers的.m文件中，其他不变，在button的响应方法里我们为block属性赋值完成block传值
RootViewControllers页面push到DetailViewControllers页面，如果DetailViewControllers页面的信息想回传（回调）到RootViewControllers页面，用代理传值，其中DetailViewControllers定义协议和声明代理，RootViewControllers确认并实现代理，RootViewControllers作为DetailViewControllers的代理
首先在DetailViewControllers.h文件中我们创建协议方法
在DetailViewControllers的.m中我们判定代理对象存在时，为其绑定相应方法
RootViewControllers的.m文件中我们指定代理并让其执行代理的方法
单例传值（实现共享）
AppStatus.h 创建一个单例类 AppStatus
#import <Foundation/Foundation.h>
@interface AppStatus : NSObject
{
NSString *_contextStr;
}
@property(nonatomic,retain)NSString *contextStr;
+(AppStatus *)shareInstance;
@endAppStatus.m
#import "AppStatus.h"
@implementation AppStatus
@synthesize contextStr = _contextStr;
static AppStatus *_instance = nil;
+(AppStatus *)shareInstance
{
if (_instance == nil)
{
_instance = [[super alloc]init];
}
return _instance;
}
-(id)init
{
if (self = [super init])
{
}
return self;
}
-(void)dealloc
{
[super dealloc];
}
@endRootViewController.h
#import "RootViewController.h"
#import "DetailViewController.h"
#import "AppStatus.h"
@interface RootViewController ()
@end
@implementation RootViewController
-(void)loadView
{
//核心代码
UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
btn.frame = CGRectMake(0, 0, 100, 30);
[btn setTitle:@"Push" forState:0];
[btn addTarget:self action:@selector(pushAction
forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:btn];
}
-(void)pushAction
id)sender
{
tf = (UITextField *)[self.view viewWithTag:1000];
//单例传值 将要传递的信息存入单例中（共享中）
// [[AppStatus shareInstance]setContextStr:tf.text]; 跟下面这种写法是等价的
[AppStatus shareInstance].contextStr = tf.text;
//导航push到下一个页面
//pushViewController 入栈引用计数+1，且控制权归系统
DetailViewController *detailViewController = [[DetailViewController alloc]init];
//导航push到下一个页面
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController release];
}
@endDetailViewController.h
#import <UIKit/UIKit.h>
@protocol ChangeDelegate;//通知编译器有此代理
@interface DetailViewController : UIViewController
{
UITextField *textField;
}
@endDetailViewController.m
#import "DetailViewController.h"
#import "AppStatus.h"
@interface DetailViewController ()
@end
@implementation DetailViewController
@synthesize naviTitle = _naviTitle;
-(void)loadView
{
self.view = [[[UIView alloc]initWithFrame:CGRectMake(0, 0, 320, 480)]autorelease];
//单例
self.title = [AppStatus shareInstance].contextStr;
textField = [[UITextField alloc]initWithFrame:CGRectMake(100, 100, 150, 30)];
textField.borderStyle = UITextBorderStyleLine;
[self.view addSubview:textField];
[textField release];
UIBarButtonItem *doneItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDonetarget:self action:@selector(doneAction:)];
self.navigationItem.rightBarButtonItem = doneItem;
[doneItem release];
}
//这个方法是执行多遍的 相当于刷新view
-(void)viewWillAppearBOOL)animated
{
[super viewWillAppear:animated];
tf = (UITextField *)[self.view viewWithTag:1000];
tf.text = [AppStatus shareInstance].contextStr;
}
//pop回前一个页面
-(void)doneActionid)sender
{
//单例传值
[AppStatus shareInstance].contextStr = textField.text;
[self.navigationController popToRootViewControllerAnimated:YES];
}谁要监听值的变化，谁就注册通知 特别要注意，通知的接受者必须存在这一先决条件
A页面RootViewController.h
#import <UIKit/UIKit.h>
#import "DetailViewController.h"
@interface RootViewController : UIViewController<ChangeDelegate>
{
UITextField *tf;
}
@endA页面RootViewController.m
#import "IndexViewController.h"
#import "DetailViewController.h"
#import "AppStatus.h"
@implementation IndexViewController
-(void)dealloc
{
[[NSNotificationCenter defaultCenter] removeObserver:self
name:@"CHANGE_TITLE" object:nil];
[super dealloc];
}
-(id)init
{
if (self = [super init])
{
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(change
name:@"CHANGE_TITLE"
object:nil];
}
return self;
}
-(void)changeNSNotification *)aNoti
{
// 通知传值
NSDictionary *dic = [aNoti userInfo];
NSString *str = [dic valueForKey:@"Info"];
UITextField *tf = (UITextField *)[self.view viewWithTag:1000];
tf.text = str;
}
-(void)viewWillAppearBOOL)animated
{
[super viewWillAppear:animated];
/*
// 单例传值
UITextField *tf = (UITextField *)[self.view viewWithTag:1000];
tf.text = [AppStatus shareInstance].contextStr;
*/
}
@endDetailViewController.h
#import <UIKit/UIKit.h>
@protocol ChangeDelegate;//通知编译器有此代理
@interface DetailViewController : UIViewController
{
UITextField *textField;
}
@endDetailViewController.m
#import "DetailViewController.h"
#import "AppStatus.h"
@implementation DetailViewController
@synthesize naviTitle = _naviTitle;
-(void)loadView
{
UIBarButtonItem *doneItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDonetarget:self action:@selector(doneAction:)];
self.navigationItem.rightBarButtonItem = doneItem;
[doneItem release];
}
// pop回前一个页面
-(void)doneActionid)sender
{
NSDictionary *dic = [NSDictionary dictionaryWithObject:textField.text forKey:@"Info"];
[[NSNotificationCenter defaultCenter] postNotificationName:@"CHANGE_TITLE" object:nil userInfo:dic];
[self.navigationController popViewControllerAnimated:YES];
}iOS 页面间几种传值方式(属性，代理，block，单例，通知)
原文：http://www.cnblogs.com/leo23/p/5051892.html