iOS 各种传值方式

 1 #import <Foundation/Foundation.h>  2   3 @interface AppStatus : NSObject  4 {  5     NSString *_contextStr;  6 }  7   8 @property(nonatomic,retain)NSString *contextStr;  9  10 +(AppStatus *)shareInstance; 11  12 @end

 1 #import "AppStatus.h"  2   3 @implementation AppStatus  4   5 @synthesize contextStr = _contextStr;  6   7 static AppStatus *_instance = nil;  8   9 +(AppStatus *)shareInstance 10 { 11     if (_instance == nil) 12     { 13         _instance = [[super alloc]init]; 14     } 15     return _instance; 16 } 17  18 -(id)init 19 { 20     if (self = [super init]) 21     { 22          23     } 24     return self; 25 } 26  27 -(void)dealloc 28 { 29     [super dealloc]; 30 } 31  32 @end

 1 #import "RootViewController.h"  2 #import "DetailViewController.h"  3 #import "AppStatus.h"  4   5 @interface RootViewController ()  6   7 @end  8   9 @implementation RootViewController 10  11 -(void)loadView 12 { 13     //核心代码  14     UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 15     btn.frame = CGRectMake(0, 0, 100, 30); 16     [btn setTitle:@"Push" forState:0]; 17     [btn addTarget:self action:@selector(pushAction:) forControlEvents:UIControlEventTouchUpInside]; 18     [self.view addSubview:btn]; 19 } 20  21 -(void)pushAction:(id)sender 22 { 23     tf = (UITextField *)[self.view viewWithTag:1000]; 24  25  //单例传值  将要传递的信息存入单例中（共享中） 26   //  [[AppStatus shareInstance]setContextStr:tf.text]; 跟下面这种写法是等价的 27     [AppStatus shareInstance].contextStr = tf.text; 28     //导航push到下一个页面 29     //pushViewController 入栈引用计数+1，且控制权归系统 30     DetailViewController *detailViewController = [[DetailViewController alloc]init]; 31  32     //导航push到下一个页面 33     [self.navigationController pushViewController:detailViewController animated:YES]; 34     [detailViewController release]; 35 }  36  37 @end

1 #import <UIKit/UIKit.h> 2 @protocol ChangeDelegate;//通知编译器有此代理 3  4 @interface DetailViewController : UIViewController 5 { 6     UITextField *textField; 7 } 8  9 @end

 1 #import "DetailViewController.h"  2 #import "AppStatus.h"  3   4 @interface DetailViewController ()  5   6 @end  7   8 @implementation DetailViewController  9  10 @synthesize naviTitle = _naviTitle; 11  12 -(void)loadView 13 { 14     self.view = [[[UIView alloc]initWithFrame:CGRectMake(0, 0, 320, 480)]autorelease]; 15  16     //单例 17     self.title = [AppStatus shareInstance].contextStr; 18     textField = [[UITextField alloc]initWithFrame:CGRectMake(100, 100, 150, 30)]; 19     textField.borderStyle = UITextBorderStyleLine; 20     [self.view addSubview:textField]; 21     [textField release]; 22  23     UIBarButtonItem *doneItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDonetarget:self action:@selector(doneAction:)]; 24     self.navigationItem.rightBarButtonItem = doneItem; 25     [doneItem release]; 26 } 27  28 //这个方法是执行多遍的  相当于刷新view 29 -(void)viewWillAppear:(BOOL)animated 30 { 31     [super viewWillAppear:animated]; 32     tf = (UITextField *)[self.view viewWithTag:1000]; 33     tf.text = [AppStatus shareInstance].contextStr; 34 } 35  36 //pop回前一个页面 37 -(void)doneAction:(id)sender 38 { 39     //单例传值 40     [AppStatus shareInstance].contextStr = textField.text; 41     [self.navigationController popToRootViewControllerAnimated:YES]; 42 } 

1 #import <UIKit/UIKit.h> 2 #import "DetailViewController.h" 3 @interface RootViewController : UIViewController<ChangeDelegate> 4 { 5     UITextField *tf; 6 } 7 @end 

 1 #import "IndexViewController.h"  2 #import "DetailViewController.h"  3 #import "AppStatus.h"  4   5 @implementation IndexViewController  6   7 -(void)dealloc  8 {  9     [[NSNotificationCenter defaultCenter] removeObserver:self 10                                                     name:@"CHANGE_TITLE" object:nil]; 11     [super dealloc]; 12 } 13  14 -(id)init 15 { 16     if (self = [super init]) 17     { 18         [[NSNotificationCenter defaultCenter] addObserver:self 19                                                  selector:@selector(change:) 20                                                      name:@"CHANGE_TITLE" 21                                                    object:nil]; 22     } 23     return self; 24 } 25  26 -(void)change:(NSNotification *)aNoti 27 { 28     // 通知传值 29     NSDictionary *dic = [aNoti userInfo]; 30     NSString *str = [dic valueForKey:@"Info"]; 31      32     UITextField *tf =  (UITextField *)[self.view viewWithTag:1000]; 33     tf.text = str; 34 } 35   36 -(void)viewWillAppear:(BOOL)animated 37 { 38     [super viewWillAppear:animated]; 39     /* 40     // 单例传值 41     UITextField *tf =  (UITextField *)[self.view viewWithTag:1000]; 42     tf.text = [AppStatus shareInstance].contextStr; 43     */ 44 } 45  46 @end

1 #import <UIKit/UIKit.h> 2 @protocol ChangeDelegate;//通知编译器有此代理 3  4 @interface DetailViewController : UIViewController 5 { 6     UITextField *textField; 7 } 8 @end

 1 #import "DetailViewController.h"  2 #import "AppStatus.h"  3   4 @implementation DetailViewController  5 @synthesize naviTitle = _naviTitle;  6   7 -(void)loadView  8 {  9     UIBarButtonItem *doneItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDonetarget:self action:@selector(doneAction:)]; 10     self.navigationItem.rightBarButtonItem = doneItem; 11     [doneItem release]; 12 } 13  14 // pop回前一个页面 15 -(void)doneAction:(id)sender 16 { 17 NSDictionary *dic = [NSDictionary dictionaryWithObject:textField.text forKey:@"Info"]; 18  19 [[NSNotificationCenter defaultCenter] postNotificationName:@"CHANGE_TITLE" object:nil userInfo:dic]; 20  21 [self.navigationController popViewControllerAnimated:YES]; 22  23 }