iOS 各种传值方式

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。

A页面DetailViewController.h文件 

#import <UIKit/UIKit.h>
#import "DetailViewController.h"
@interface RootViewController :UIViewController<ChangeDelegate>
{
    UITextField *tf;
}
@end

A RootViewController.m页面实现文件

#import "RootViewController.h"
#import "DetailViewController.h"

@interface RootViewController ()
@end

@implementation RootViewController
//核心代码
-(void)loadView
{
    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.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 =tf.text;
    //导航push到下一个页面
    [self.navigationControllerpushViewController:detailViewController animated:YES];
    [detailViewControllerrelease];   
}

B页面DetailViewController.h文件

#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 ;    
}

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 *tf;
}
@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 *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    btn.frame = CGRectMake(0, 0, 100, 30);
    [btn setTitle:@"Push" forState:0];
    //A页面push到B页面
    [btn addTarget:self action:@selector(pushAction:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:btn];
}

-(void)pushAction:(id)sender
{
    tf = (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
{
    tf = (UITextField *)[self.view viewWithTag:1000];
    tf.text = aStr;//将从B页面传入的参数赋给A页面中的TextField
    tf.text = aStr;
}

B页面DetailViewController.m文件

#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.h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:UIBarButtonSystemItemDonetarget:selfaction:@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.delegatechangeTitle: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.navigationControllerpopViewControllerAnimated:YES];
    }
} 

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

#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.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];
} 

@end

B页面DetailViewController.h

#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];
} 

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];

}

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

#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