1.通过属性传值
将A页面所拥有的信息通过属性传递到B页面使用,B页面定义了一个naviTitle属性，在A页面中直接通过属性赋值将A页面中的值传到B页面。
#import <UIKit/UIKit.h>
#import "DetailViewController.h"
@interface RootViewController :UIViewController<ChangeDelegate>
{
UITextField *textField;
}
@end
A页面 RootViewController.m面实现文件
#import "RootViewController.h"
#import "DetailViewController.h"
@interface RootViewController ()
@end
@implementation RootViewController
//核心代码
-(void)loadView
{
UIButton *BT = [UIButton buttonWithType:UIButtonTypeRoundedRect];
BT.frame = CGRectMake(0, 0, 100, 30);
[BT setTitle:@"Push" forState:0];
[BT addTarget:self action:@selector(pushAction:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:btn];
}
-(void)pushAction:(id)sender
{
textField = (UITextField *)[self.viewviewWithTag:1000];
//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 = [[DetailViewControlleralloc]init];
//属性传值，直接属性赋值
detailViewController.naviTitle =textField.text;
//导航push到下一个页面
[self.navigationControllerpushViewController:detailViewController animated:YES];
[detailViewControllerrelease];
}
#import <UIKit/UIKit.h>
@interface DetailViewController :UIViewController
{
UITextField *textField;
NSString *_naviTitle;
}
@property(nonatomic,retain)NSString *naviTitle;
@end
B页面.m实现文件
#import "DetailViewController.h"
@interface DetailViewController ()
@end
@implementation DetailViewController
@synthesize naviTitle =_naviTitle;
-(void)loadView
{
self.view =
[[[UIViewalloc]initWithFrame:CGRectMake(0,0, 320,480)]autorelease];
self.title = self.naviTitle ;
}
2.代理传值
A页面push到B页面，如果B页面的信息想回传（回调）到A页面，用代理传值，其中B定义协议和声明代理，A确认并实现代理，A作为B的代理
A页面RootViewController.h文件
#import <UIKit/UIKit.h>
#import "DetailViewController.h"
@interface RootViewController : UIViewController<ChangeDelegate>
{
UITextField *textField;
}
@end
A页面RootViewController.m实现文件
#import "RootViewController.h"
#import "DetailViewController.h"
@interface RootViewController ()
@end
@implementation RootViewController
//核心代码
-(void)loadView
{
UIButton *BT = [UIButton buttonWithType:UIButtonTypeRoundedRect];
BT.frame = CGRectMake(0, 0, 100, 30);
[btn setTitle:@"Push" forState:0];
//A页面push到B页面
[BT addTarget:self action:@selector(pushAction:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:BT];
}
-(void)pushAction:(id)sender
{
textField = (UITextField *)[self.view viewWithTag:1000];
//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];
//代理传值
detailViewController.delegate =self;//让其自身作为代理人
//导航push到下一个页面
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController release];
}
//实现代理方法
-(void)changeTitle:(NSString *)aStr
{
textField = (UITextField *)[self.view viewWithTag:1000];
textField.text = aStr;//将从B页面传入的参数赋给A页面中的TextField
textField.text = aStr;
}
B页面DetailViewController.m文件
B 页面 DetailViewController.h
#import <UIKit/UIKit.h>
@interface DetailViewController : UIViewController
{
UITextField *textField;
//定义代理
id<ChangeDelegate>_delegate;
}
@property(nonatomic,assign)id<ChangeDelegate>
delegate;
@end
//定义协议
@protocol ChangeDelegate <NSObject>
-(void)changeTitle:(NSString *)aStr;//协议方法
@end
B页面DetailViewController.m实现文件
#import "DetailViewController.h"
@interface DetailViewController ()
@end
@implementation DetailViewController
-(void)loadView
{
self.view =
[[[UIView alloc]initWithFrame:CGRectMake(0, 0, 320, 480)] autorelease];
UIBarButtonItem *doneItem = [[UIBarButtonItemalloc]initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(doneAction:)];
self.navigationItem.rightBarButtonItem =
doneItem;
[doneItemrelease];
}
//pop回前一个页面
-(void)doneAction:(id)sender
{
if (self.delegate &&
[self.delegaterespondsToSelector:@selector(changeTitle:)])//若代理存在且响应了changeTitle这个方法
{
//[self.delegate changeTitle:textField.text];
[self.delegate changeTitle:textField.text];//将textField.text参数传给changeTitle方法 让代理，也就是A页面去实现这个方法
NSLog(@"%@",self.navigationController.viewControllers);
[self.navigationController popViewControllerAnimated:YES];
}
}
3.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;
@end
AppStatus.m 页面
#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];
}
@end
A页面 RootViewController
#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];
}
@end
B页面DetailViewController.
#import <UIKit/UIKit.h>
@protocol ChangeDelegate;//通知编译器有此代理
@interface DetailViewController : UIViewController
{
UITextField *textField;
}
@end
B页面 DetailViewController.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)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
tf = (UITextField *)[self.view viewWithTag:1000];
tf.text =
[AppStatus shareInstance].contextStr;
}
//pop回前一个页面
-(void)doneAction:(id)sender
{
// 单例传值
[AppStatus shareInstance].contextStr = textField.text;
[self.navigationController popToRootViewControllerAnimated:YES];
}
4. 通知传值 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;
}
@end
A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)change:(NSNotification *)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)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
/*
// 单例传值
UITextField *tf = (UITextField *)[self.view viewWithTag:1000];
tf.text = [AppStatus shareInstance].contextStr;
*/
}
@end
DetailViewController.h
#import <UIKit/UIKit.h>
@protocol ChangeDelegate;//通知编译器有此代理
@interface DetailViewController : UIViewController
{
UITextField *textField;
}
@end
DetailViewController.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)doneAction:(id)sender
{
NSDictionary *dic = [NSDictionary dictionaryWithObject:textField.text forKey:@"Info"];
[[NSNotificationCenter defaultCenter] postNotificationName:@"CHANGE_TITLE" object:nil userInfo:dic];
[self.navigationController popViewControllerAnimated:YES];
}
5.Block
几种形式的Block
//无返回值
void (^block1) (void);
block1 = ^{
NSLog(@"bock demo");
};
block1();
//int返回类型
int (^block2) (void);
block2 = ^(void)
{
int a = 1 ,b =1;
int c = a+b;
return c;
};
//有返回 有参数
int (^block3)(int, int)= ^(int a, int b)
{
int c = a +b;
return c;
};
NSLog(@"bock=%d",block3(1,2));
//有返回值，有参数并且可以修改block之外变量的block
static int sum = 10;// __blcik and static关键字 或者 _block int sum = 10
int (^block4) (int) =^(int a)
{
sum=11;
int c = sum+a; //此时sum就是可以修改的了，若没加static或_block关键字则不能修改block之外变量
return c;
};
NSLog(@"block4= %d",block4(4));
Block传值
例如A(Ablock)页面的值传道B(Bblock)页面
在A页面中 ABlock.h
@interface Ablock : UIViewController<UITableViewDelegate,UITableViewDataSource>
{
UITableView *_tableview;
UILabel *labe;
UIImageView *imagevies;
}
@end
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[_tableview deselectRowAtIndexPath:indexPath animated:YES];
Bblcok *bblock = [[Bblcok alloc] initwithBlock:Block_copy(^(NSString *aBlock){
labe.text = aBlock;
NSLog(@"%@",aBlock);
})];
bblock.imgeviews = imagevies.image;
bblock.String = labe.text;
[self.navigationController pushViewController:bblock animated:YES];
[bblock release];
}
在A页面中 Bblock.h
#import <UIKit/UIKit.h>
typedef void (^MyBlock) (NSString *);
@interface Bblcok : UIViewController
{
UIImageView *image;
UITextField *aField;
UIButton *aButt;
NSString *_String;
id _imgeviews;
MyBlock myBlock;
}
@property(nonatomic,copy)MyBlock myBlock;
@property(nonatomic,retain) id imgeviews;
@property(nonatomic,retain) NSString *String;
-(id)initwithBlock:(MyBlock)aBlcok;
@end
//
// Bblcok.m
// Blcok
//
// Created by zhu on 13-8-12.
// Copyright (c) 2013年 Zhu Ji Fan. All rights reserved.
//
#import "Bblcok.h"
@interface Bblcok ()
@end
@implementation Bblcok
@synthesize imgeviews = _imgeviews , String = _String;
@synthesize myBlock = _myBlock;
-(id)initwithBlock:(MyBlock)aBlcok
{
if (self = [super init])
{
self.myBlock = aBlcok;
}
return self;
}
-(void) dealloc
{
[super dealloc];
}
-(void) loadView
{
UIControl *cont = [[UIControl alloc] initWithFrame:CGRectMake(0, 0, 320, 568-44)];
[cont addTarget:self action:@selector(Clcik) forControlEvents:UIControlEventTouchUpInside];
self.view = cont;
aField = [[UITextField alloc] initWithFrame:CGRectMake(60, 10, 160, 30)];
aField.borderStyle = UITextBorderStyleLine;
aField.placeholder = self.String;
[self.view addSubview:aField];
aButt = [UIButton buttonWithType:UIButtonTypeRoundedRect];
aButt.frame = CGRectMake(60, 50, 70, 30);
[aButt setTitle:@"修改" forState:0];
[aButt addTarget:self action:@selector(aButtClcik:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:aButt];
image = [[UIImageView alloc] initWithFrame:CGRectMake(60, 100, 210, 260)];
image.backgroundColor = [UIColor blueColor];
image.image = self.imgeviews;
[self.view addSubview:image];
[image release];
}
-(IBAction)aButtClcik:(id)sender
{
NSString *sting = aField.text;
myBlock(sting);
[self.navigationController popToRootViewControllerAnimated:YES];
}
-(void)Clcik
{
[aField resignFirstResponder];
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end