单例传值 ------- 如果页面之间相隔很多,要进行传值,将值保存到第三方,将第三方设置为单例模式

代码如下:

<pre name="code" class="objc">#import <Foundation/Foundation.h>

@interface Singleton : NSObject
+ (Singleton *)shareSingleton;
@property (nonatomic,copy)NSString * text;
@end

#import "Singleton.h"

@implementation Singleton

static Singleton * singleton = nil;
+ (Singleton *)shareSingleton
{
    @synchronized(self){
        if (singleton == nil) {
            singleton = [[Singleton alloc]init];
        }
    }
    return singleton;
}
@end

#import "FirstViewController.h"
#import "SecondViewController.h"
#import "UIButton+Create.h"
#import "Singleton.h"
@interface FirstViewController ()
{
    UITextField * _textField;//创建一个输入框
}
@end

@implementation FirstViewController
- (void)dealloc
{
    [_textField release];
    [super dealloc];
}
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    
    self.view.backgroundColor = [UIColor redColor];
    self.navigationItem.title = @"首页";
    /**
     *  1.在第一个界面创建一个输入框
     *  
     */
    _textField = [[UITextField alloc]initWithFrame:CGRectMake(50, 80, 200, 30)];
    _textField.borderStyle = UITextBorderStyleRoundedRect;
    [self.view addSubview:_textField];
    
    
    /**
     *  1.创建一个UIButton,
     *  2.并添加响应事件,从首页跳转到第二个页面.
     */
    UIButton * button = [UIButton systemButtonWithFrame:CGRectMake(100, 120, 50, 50) title:@"Push" target:self action:@selector(didClickButtonAction)];
    [self.view addSubview:button];
    
    
	// Do any additional setup after loading the view.
}

- (void)didClickButtonAction
{
    
    /**
     *  1.用push的方法推出下一个页面
     *  2.把首页输入框输入的字符串,通过单例来接收
     *  3.从而实现把首页输入框输入的字符串,传到第二页的UILabel上.
     */
    SecondViewController * secondVC = [[SecondViewController alloc]init];
    [Singleton shareSingleton].text = _textField.text;
    [self.navigationController pushViewController:secondVC animated:YES];
    [secondVC release];
}


- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

#import "SecondViewController.h"
#import "Singleton.h"
@interface SecondViewController ()

@end
@implementation SecondViewController

- (void)dealloc
{
    [_label release];
    [super dealloc];
}
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor orangeColor];
    self.navigationItem.title = @"第二页";
    /**
     *  1.在第二个界面创建一个UILabel
     *  2.把首页输入框输入的字符串,通过单例类的属性NSString * text接收
     *  3.然后通过赋值给UILabel
     */
    _label = [[UILabel alloc]initWithFrame:CGRectMake(50, 80, 200, 30)];
    _label.backgroundColor = [UIColor greenColor];
    
    _label.text = [Singleton shareSingleton].text;
    
    [self.view addSubview:_label];
    
	// Do any additional setup after loading the view.
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

单例传值