NSnotification DeMo

本文详细介绍了如何使用App Delegate与ViewController配合实现一个带有Tab栏的应用,包括窗口初始化、视图控制器配置以及Tab栏的定制。通过实例代码展示了如何在启动应用时设置根视图控制器为TabBarController,并在ViewController中实现图像切换、头像更新等功能。

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Appdelegate.h

*************************************

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

{

    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];

    // Override point for customization after application launch.

    self.viewController = [[[ViewController alloc] initWithNibName:@"ViewController" bundle:nil] autorelease];

    

    FirstViewController *first=[[FirstViewController alloc]init];

    SecondViewController *second=[[SecondViewController alloc]init];

    

    UITabBarController *tabBar=[[UITabBarController alloc]init];

    [tabBar setToolbarItems:[NSArray arrayWithObjects:@"first",@"second", nil] animated:YES];

    [tabBar setViewControllers:[NSArray arrayWithObjects:first,second, nil]];

    

    [(UITabBarItem *)[tabBar.tabBar.items objectAtIndex:0] setTitle:@"frist"];

    [(UITabBarItem *)[tabBar.tabBar.items objectAtIndex:0] setImage:[UIImage imageNamed:@"first.png"]];  //30 * 30

    [(UITabBarItem *)[tabBar.tabBar.items objectAtIndex:1] setTitle:@"second"];

    [(UITabBarItem *)[tabBar.tabBar.items objectAtIndex:1] setImage:[UIImage imageNamed:@"second.png"]];

    

   

    self.window.rootViewController = tabBar;

    [self.window makeKeyAndVisible];

    return YES;

}


******************

ViewController.m

****************************

- (void)viewDidLoad

{

    [super viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.

    imageView=[[UIImageView alloc]initWithFrame:CGRectMake(20, 100, 270, 200)];

    imageView.backgroundColor=[UIColor whiteColor];

    

    NSUserDefaults *defaults=[NSUserDefaults standardUserDefaults];

    if ([defaults objectForKey:@"Header"])

    {

        UIImage *image=[UIImage imageWithData:[defaults objectForKey:@"Header"]];

        imageView.image=image;

    }

    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(ChangeHeader:) name:@"MyHeader" object:nil];

   

   

    

    [self.view addSubview:imageView];    

    

    UIButton *btnidentity=[UIButton buttonWithType:UIButtonTypeRoundedRect];

    btnidentity.frame=CGRectMake(60, 350, 70, 30);

    btnidentity.tintColor=[UIColor greenColor];

    [btnidentity setTitle:@"切换图片" forState:UIControlStateNormal];

    [btnidentity setTitleColor:[UIColor greenColor] forState:UIControlStateNormal];

    [btnidentity addTarget:self action:@selector(ChangeImage:) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:btnidentity];

        

    UIButton *btnCancel=[UIButton buttonWithType:UIButtonTypeRoundedRect];

    btnCancel.frame=CGRectMake(150, 350, 70, 30);

    btnCancel.tintColor=[UIColor greenColor];

    [btnCancel setTitleColor:[UIColor redColor] forState:UIControlStateNormal];

    [btnCancel setTitle:@"取消" forState:UIControlStateNormal];

    [btnCancel addTarget:self action:@selector(CancelImage:) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:btnCancel];

}

-(void)ChangeImage:(id)sender

{

    UIImagePickerController *pickerController=[[UIImagePickerController alloc]init];

    pickerController.sourceType=UIImagePickerControllerSourceTypePhotoLibrary;

    pickerController.mediaTypes=[UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypePhotoLibrary];

    pickerController.allowsEditing=YES;

    pickerController.delegate=self;

    [self presentViewController:pickerController animated:YES completion:nil];

    [pickerController release];

   

}

-(void)ChangeHeader:(NSNotification *)obj

{

    self.imageView.image=obj.object;

}

-(void)CancelImage:(id)sender

{

    [self dismissViewControllerAnimated:YES completion:nil];

}

- (void)didReceiveMemoryWarning

{

    [super didReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.

}

#pragma delegate

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info

{

    NSLog(@"info:%@",info);

    UIImage *image=[info objectForKey:UIImagePickerControllerOriginalImage];

    NSLog(@"image%@",image);

    self.imageView.image=image;

    [picker dismissViewControllerAnimated:YES completion:nil];

    

    [[NSNotificationCenter defaultCenter]postNotificationName:@"MyHeader" object:image userInfo:Nil];

    NSUserDefaults *defaults=[NSUserDefaults standardUserDefaults];

    [defaults setObject:UIImageJPEGRepresentation(image, 1) forKey:@"Header"];

    [defaults synchronize];

}

- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker

{

    [picker dismissViewControllerAnimated:YES completion:nil];

}

#pragma -------

****************************
FirstViewController

*************

- (void)viewDidLoad

{

    [super viewDidLoad];

// Do any additional setup after loading the view.

    self.view.backgroundColor=[UIColor clearColor];

    Header=[[UIImageView alloc]initWithFrame:CGRectMake(30, 100, 320, 200)];

    Header.backgroundColor=[UIColor whiteColor];

    

    NSUserDefaults *defaults=[NSUserDefaults standardUserDefaults];

    if ([defaults objectForKey:@"Header"])

    {

         UIImage *image=[UIImage imageWithData:[defaults objectForKey:@"Header"]];

         self.Header.image=image;        

    }

    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(ChangeHeader:) name:@"MyHeader" object:nil];

    [self.view addSubview:Header];

}

-(void)ChangeHeader:(NSNotification *)obj

{

    self.Header.image=obj.object;

}

- (void)didReceiveMemoryWarning

{

    [super didReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.

}


**********************

SecondViewController

**********

- (void)viewDidLoad

{

    [super viewDidLoad];

// Do any additional setup after loading the view.

    self.view.backgroundColor=[UIColor clearColor];

    Header=[[UIImageView alloc]initWithFrame:CGRectMake(30, 100, 320, 200)];

    Header.backgroundColor=[UIColor whiteColor];

    NSUserDefaults *defaults=[NSUserDefaults standardUserDefaults];

    if ([defaults objectForKey:@"Header"])

    {

        UIImage *image=[UIImage imageWithData:[defaults objectForKey:@"Header"]];

        self.Header.image=image;

    }

   

    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(ImageChange:) name:@"MyHeader" object:nil];

   

    UIButton *button=[UIButton buttonWithType:UIButtonTypeRoundedRect];

    button.frame=CGRectMake(150, 350, 70, 30);

    [button addTarget:self action:@selector(changeImage) forControlEvents:UIControlEventTouchUpInside];

    [button setTitle:@"更换图片" forState:UIControlStateNormal];

    

    [self.view addSubview:Header];

    [self.view addSubview:button];

}

-(void)changeImage

{

    ViewController *viewController=[[ViewController alloc]initWithNibName:@"ViewController" bundle:nil]; 

    [self presentViewController:viewController animated:YES completion:nil];

}

-(void)ImageChange:(NSNotification *)obj

{

    self.Header.image=obj.object;

}

- (void)didReceiveMemoryWarning

{

    [super didReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.

}


********

通知的小Demo,留作己用


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