Lala's Program Note 實作記錄: 6. NSFetchedResultsController 之三

since: 2011/08/30
update: 2011/12/01

將 Fetched Results Controller 合併到 Table 中.


A. 修改 NoteBookViewController.m 如下:
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    // Return the number of sections.
    return [[self.fetchedResultsController sections] count]; // it always return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    // Return the number of rows in the section.
    id<NSFetchedResultsSectionInfo> sectionInfo = [[fetchedResultsController sections] objectAtIndex:section];

    return [sectionInfo numberOfObjects];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"NoteBookCell";
   
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    }
   
    // Configure the cell...
    // * need to implement the configureCell:atIndexPath: method
    [self configureCell:cell atIndexPath:indexPath];
   
    return cell;
}

----------------------------------------------------------------------------------------------------------

B. 在 NoteBookViewController.m 裡, 實作 configureCell:atIndexPath: method
      1. 在 @implementation 字串的前一行宣告一個區塊式的 private method:
@interface NoteBookViewController() // 小括號
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath;
@end

@implementation NoteBookViewController

      2. 接著在實作區, 實作此 method:
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath {
    NSManagedObject *noteBook = [self.fetchedResultsController objectAtIndexPath:indexPath];

    cell.textLabel.text = [noteBook valueForKey:@"name"];
    cell.textLabel.textColor = [UIColor brownColor];
}

----------------------------------------------------------------------------------------------------------

C. 當使用者移動或刪除一列資料 (in this case, we can only delete it)
      1. 在 NoteBookViewController.h 新增以下的 method:
         - (void)saveContext;

     2. 在 NoteBookViewController.m 新增以下的 method:

- (void)saveContext {
    NSManagedObjectContext *context = [fetchedResultsController managedObjectContext];

    NSError *error = nil;
    if (![context save:&error]) {
        NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
        abort();
    }
}

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (editingStyle == UITableViewCellEditingStyleDelete) {
        // Delete the managed object for the given index path
        NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];

        [context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]];
       
        // Save the context      
        [self saveContext];
    }
}

----------------------------------------------------------------------------------------------------------

D. 在 Lala_s_Program_NoteAppDelegate.m 中提供 managed object contexts 給
        noteBookViewController :
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    NoteBookViewController *noteBookViewController = [[NoteBookViewController alloc] initWithStyle:UITableViewStylePlain];

    // set controller's managed object context member right after initializing
    noteBookViewController.managedObjectContext = self.managedObjectContext;
    ....

}

Lala's Program Note 實作記錄: 5. NSFetchedResultsController 之二

since: 2011/08/30
update: 2011/08/30

A. 說明:
   1. 之前由於已將 NoteBookViewController 設為 fetchedResultsController 成員變數
      的 delegate, 所以必須實作 NSFetchedResultsControllerDelegate 這個 protocol
      的 methods.

B. 實作 NSFetchedResultsControllerDelegate protocol 的 methods:
   在 NoteBookViewController.m 實作以下的 methods.

#pragma mark -
#pragma mark Fetched results controller delegate
// * tells this controller's table view to start a series of updates
// * it can initiate a sequence of changes through its beginUpdates: method.
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
    [self.tableView beginUpdates];
}

// * is called when the changes are done.
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
    [self.tableView endUpdates];
}

// only for supports sections (目前沒用到)
// * is called when a section changes(added or deleted)
/*
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id<NSFetchedResultsSectionInfo>)sectionInfo atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type {

    switch (type) {
        case NSFetchedResultsChangeInsert:
            [self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
            break;
           
        case NSFetchedResultsChangeDelete:
            [self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
            break;
    }
}
*/

// * is called when a managed object changes(added, deleted, edited, or moved)
// * 需要再配合之後實作 configureCell:atIndexPath: method
// * configureCell:atIndexPath: method will be responsible for configuring a single table cell, 
//   and you will reuse this method in the tableView:cellForRowAtIndexPath: method.
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath {
   
    UITableView *tableView = self.tableView;
    switch (type) {
        // An object has been added (inserted)
        case NSFetchedResultsChangeInsert:
            [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;
           
        // An object has been deleted
        case NSFetchedResultsChangeDelete:
            [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;
           
        // An object has been updated (edited)
        case NSFetchedResultsChangeUpdate:
            // need to implement the configureCell:atIndexPath: method
            [self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
            break;
           
        // An object has been moved (not used here)
        /*   
        case NSFetchedResultsChangeMove:
            [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];

            [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;
        */
    }
}

Lala's Program Note 實作記錄: 4. NSFetchedResultsController 之一

since: 2011/08/29
update: 2011/08/29

參考書籍:
Pro Core Data for iOS: Data Access and Persistence Engine for iPhone, iPad, and iPod touch

A. 說明:
   1. NSFetchedResultsController 是設計用來讓 Core Data 與 Table view 整合的類別.


B. 為瀏覽筆記本(NoteBook) 加上 NSFetchedResultsController:
   1. 修改 NoteBookViewController.h 如下:
#import <UIKit/UIKit.h>
#import <CoreData/CoreData.h>
@interface NoteBookViewController : UITableViewController {
@interface NoteBookViewController : UITableViewController <NSFetchedResultsControllerDelegate> {
    NSFetchedResultsController *fetchedResultsController;
    NSManagedObjectContext *managedObjectContext;
}
@property (nonatomic, retain) NSFetchedResultsController *fetchedResultsController;
@property (nonatomic, retain) NSManagedObjectContext *managedObjectContext;
@end

----------------------------------------------------------------------------------------------------------

   2. 修改 NoteBookViewController.m 如下:

@synthesize fetchedResultsController, managedObjectContext;

- (void)dealloc {
    [fetchedResultsController release];
    [managedObjectContext release];
    [super dealloc];
}


----------------------------------------------------------------------------------------------------------

   3. 在 NoteBookViewController.m 建立 Fetched Results Controller
      // Do it in the accessor for the fetchedResultsController member
#pragma mark -
#pragma mark Fetched results controller

- (NSFetchedResultsController *)fetchedResultsController {
    if (fetchedResultsController != nil) {
        return fetchedResultsController;
    }

    // Create the fetch request for the entity
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];

    NSEntityDescription *entity = [NSEntityDescription entityForName:@"NoteBook" inManagedObjectContext:self.managedObjectContext];

    [fetchRequest setEntity:entity];

    // Set the batch size
    [fetchRequest setFetchBatchSize:10];

    // sort by noteBook name, ascending
    // * with Fetched Results Controller, you must have at least one sort descriptor.
    NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES];

    NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];

    [fetchRequest setSortDescriptors:sortDescriptors];

    // Create the fetched results controller using the fetch request we just created,
    // and with the managed object context member,
    // and set this controller to be the delegate
    // * we pass nil for the sectionNameKeyPath parameter,
    //   because we have no sections.
    NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:nil cacheName:@"NoteBook"];
   
    aFetchedResultsController.delegate = self;
    self.fetchedResultsController = aFetchedResultsController;

    // Clean up
    [aFetchedResultsController release];
    [fetchRequest release];
    [sortDescriptor release];
    [sortDescriptors release];

    // Fetch the results into the fetched results controller
    NSError *error = nil;
    if (![[self fetchedResultsController] performFetch:&error]) {
        //TODO
        NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
        abort();
    }
   
    return fetchedResultsController;
}

Lala's Program Note 實作記錄: 3.建立資料模型

since: 2011/08/27
update: 2011/08/29

A. 說明:
   1. Core Data manages an object graph using real object references. It has no need
      for a unique autoincrement identifier that can be used as a primary key in the
      same sense it would be used in a relational database.
      備註: a. 譯: Core Data 使用真實的物件參照來管理物件圖表, 因此不需要像
                        關聯式資料庫那樣使用自動新增的獨一無二 ID 來當主鍵.
               b. Core Data is not a database; it's an object graph persistence framework.

   2. All Core Data attributes must have a class type.
      ex: Entity: Organization
            Attribute: id (with type: Integer 16)
            // a. create a primitive int from the hash of the organization object
            NSManagedObject *organization = ....;
            int orgID = [organization hash]; 
         
            // b. convert the primitive int into an NSNumber object,
            // which can be used in the setValue:forKey: method.
            [organization setValue:[NSNumber numberWithInt:orgID] forKey:@"id"];

   3. Core Data returns the "many" side of a one-to-many relationship as a set(NSSet).
      ex: add some employees to the relationship
           NSManagedObject *john = ....;
           NSManagedObject *jane = ....;
           NSManagedObject *bill = ....;
        
          NSMutableSet *johnsEmployees = [john mutableSetValueForKey:@"employees"];

          [johnsEmployees addObject:jane];
          [johnsEmployees addObject:bill];


B. 資料模型規劃:
   Entity:
   NoteBook ----> 筆記本

   Attributes:
   name (type: string) ----> 筆記本名稱(必要)
   subName (type: string) ----> 筆記本副名稱(非必要)
   articleCount (type: int 16) ----> 文章數量(必要, 預設值:0)
   type (type: int 16) ----> 種類(系統預設的, 使用者新增的), (必要, 預設值:0)
   dateCreated (type: Date) ----> 建立日期 (非必要)
   dateUpdate (type: Date) ----> 更新日期 (非必要)
   status (type: int 16) ----> 筆記本狀態 (正常, 刪除), (必要, 預設值:1)
   flag (type: int 16) ----> 備用旗標, (非必要, 預設值:0)
   ---------------------------------------------------------------------------------------------------------------
   Entity:
   NoteArticle ----> 筆記文章

   Attributes:  
   title (type: string) ----> 英文標題(或使用者新增的) (必要, indexed)
   titleC (type: string) ----> 中文標題 (非必要, indexed)
   subTitle (type: string) ----> 副標題 (非必要)
   content (type: string) ----> 英文內容(或使用者新增的) (必要)
   contentC (type: string) ----> 中文內容 (非必要)
   readCount (type: int 16) ----> 文章讀取次數, (必要, 預設值:0)
   favorite (type: Boolean) ----> 是否為我的最愛, (必要, 預設值:NO)
   type (type: int 16) ----> 文章種類(系統預設的, 使用者新增的), (必要, 預設值:0)
   version (type: string) ----> 適用的版本 (非必要)
   memo (type: string) ----> 備註攔 (非必要)
   dateCreated (type: Date) ----> 建立日期 (非必要)
   dateUpdate (type: Date) ----> 更新日期 (非必要)
   status (type: int 16) ----> 文章狀態 (正常, 刪除), (必要, 預設值:1)
   flag (type: int 16) ----> 備用旗標, (非必要, 預設值:0)
   ---------------------------------------------------------------------------------------------------------------
   Relationship:
   from: NoteBook
   Name: articles
   Destination: NoteArticle
   Properties: Optional
   Plural: To-Many Relationship (一對多)
   Delete Rule: Cascade (瀑布似地)
   ---------------------------------------------------------------------------------------------------------------
   Relationship:
   from: NoteArticle
   Name: book
   Destination: NoteBook
   Inverse: articles
   Properties: Optional
   Delete Rule: Nullify (廢棄)


C. 建立完成:

Core Data 資料(sqlite)的管理工具

since: 2011/08/20
update: 2011/08/20

A. 某個有使用 Core Data 的專案, 包含二個 Entity 如下所示:

B. 使用 free 的 SQLite Database Browser:
   1. 下載網址: http://sqlitebrowser.sourceforge.net/

   2. 使用方式: 打開 App 後, 直接瀏覽專案內的 xxx.sqlite 檔, 並開啟.
                        說明: 先參考這篇, 將 Xcode 的 iPhone Simulator 目錄位置
                                建立 symbolic link, 才瀏覽的到.

   3. 開啓後, 如下所示:
      Database Structure:

  
     Browse Data:

   優點: 可以看到整個 Core Data 所產生的 sqlite 資料庫內容.
   缺點: 要管理資料庫中的 Entity, Attributes 與 Relationships 不太方便.

C. 使用 Mac App Store 的 Core Data Editor:
   1. 要花費 $39.99 USD: Core Data Editor on the Mac App Store  

   2. 使用方式:
      a. 打開 App 後, File > New

      b. 點選中間上方的 Configuration

      c. 在 Model 頁籤, 填入以下資料:
         Name: 可取與 app 同名.
         Model Path: 選到 Xcode 的 iPhone Simulator 目錄下 .... 的 .app 檔.

      d. 在 Stroes 頁籤, 填入以下資料:
         Name: 名稱
         Location: 選到 Xcode 的 iPhone Simulator 目錄下 .... 的 .sqlite 檔.
         Type: 選 SQLite

      e. 接著: File > Save 儲存後, 即可關閉 Configuration 視窗.

      f. 管理界面, 如下所示:
     Entity: Artist

     Entity: Release

     Relationships: Artist ---- (creation) ----> Release

     Relationships: Release ---- (creator) ----> Artist

   3. 優缺點
      優點: Entity, Attributes 與 Relationships 資料的呈現較清楚.
      缺點: 費用不少, 沒有批次匯入匯出功能 .

Create symbolic link for iTunes backup & iPhone Simulator Directory

since: 2011/08/20
update: 2011/08/21

A. 說明: 為 iTunes 備份檔案的目錄與 Xcode 的 iPhone Simulator 目錄,
            建立 symbolic link (軟連結, 就像捷徑), 方便平常的使用.
            (因為是在個人目錄下, 正常情況 Finder 是無法搜尋到, 也無法進入)

B. 步驟:
   1. 打開終端機

   2. iTunes:
      a. 進入 iTunes 備份檔案的位置:
         $ cd /Users/lanli/Library/Application\ Support/MobileSync/

      b. 回到根目錄, 查詢 ln 的語法
        $ cd /
        $ ln
          usage: ln [-Ffhinsv] source_file [target_file]
                  ln [-Ffhinsv] source_file ... target_dir
                  link source_file target_file

      c. 在根目錄建立一個名為 MobileSync 的 symbolic link, 連結到
         /Users/lanli/Library/Application Support/MobileSync 目錄內:
         $ sudo ln -s /Users/lanli/Library/Application\ Support/MobileSync/ MobileSync
 
      d. 查看新建好的連結:
         $ ls -al MobileSync
         MobileSync -> /Users/lanli/Library/Application Support/MobileSync/

      e. 打開 Finder, 將剛剛在根目錄建好的 MobileSync 資料夾,
         拖拉至 Dock 上, 即可方便開啓.

   3. Xcode 的 iPhone Simulator 目錄位置:
      /Users/lanli/Library/Application Support/iPhone Simulator
      說明: a. 可同之前的步驟來建立.(建議可以只建 symbolic link 到 Mac 的根目錄).
               b. 在開啓的資料夾, 與 MobileSync 同ㄧ目錄內就可以看到
                  iPhone Simulator 目錄了.

   4. 建好的 MobileSync 與 iPhone Simulator symbolic link 在 Mac 根目錄下的狀況:

Lala's Program Note 實作記錄: 2.標籤列架構

since: 2011/08/18
update: 2011/09/16

參考: Creating an iOS 4 iPhone Multiview Application using the Tab Bar (Xcode 4) - Techotopia

A. 專案目錄規劃:
   專案目錄 > New Group:

   新增 3 個群組資料夾: images、MyClasses、XIB, 並可將相關檔案移至資料夾內.

B. 新增 root controller 程式碼: (改成用 coding 的方式)
1. 在 Lala_s_Program_NoteAppDelegate.h 新增 UITabBarController
(當作 root controller)的相關程式碼:

@interface Lala_s_Program_NoteAppDelegate : NSObject
{
UIWindow *window;

UITabBarController *tabBarController; 

}

@property (nonatomic, retain) IBOutlet UIWindow *window;

@property (nonatomic, retain) IBOutlet UITabBarController *tabBarController;

2. 在 Lala_s_Program_NoteAppDelegate.h 新增相關程式碼:

@synthesize window = _window;

@synthesize tabBarController;

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

{
// Override point for customization after application launch.

tabBarController = [[UITabBarController alloc] init];

[self.window addSubview:tabBarController.view];
[self.window makeKeyAndVisible];

return YES;

}

- (void)dealloc

{

[tabBarController release];
[_window release];

[__managedObjectContext release];

[__managedObjectModel release];

[__persistentStoreCoordinator release];

[super dealloc];

}

(由於已改成用 coding 的方式, 因此這段不用做, 僅留參考用)

C. 編輯 MainWindow.xib 檔案:

1. (重要)點選 MainWindow.xib 後, 再點最下方的 right facing arrow (朝右方的箭頭), 以顯示 Placeholder 跟 Objects 的 panel .

2. (重要)從 Object library panel (View -> Utilities -> Object Library) 點選 Tab Bar Controller , 並拖拉至 Objects panel 內的 Window icon 下方, 並將新增加的 Tab Bar Controller Object 左邊的箭頭點開. 接著, 依次選取展開的 View Controller - Item 1 與 View Controller - Item 2, 並按 delete 刪除, 結果如下:

3. 連接接口:
   先點選左方 Objects 下的 Lala's Program NoteAppDelegate,
   接著點住右上方 Outlets 下的 Tab Bar Controller 拖拉至 UI 上.

D. 製作給 Categories, Buy 與 Info 頁籤使用的圖檔:
說明: 在 Mac App Store 買了一個 icon 的製作軟體:
Icon Maker , 先用 Icon Maker 製作 icon,
後來發現無法將背景設為透明, 因此再用 Photoshop 處理,

並輸出成適當的 size.

1. 圖檔規格:
   (a). PNG 檔
   (b). 建議 size: 30 * 30 ~ 40 * 40(pixel)
   (c). 不能為彩色的圖片(一般使用灰色)
   (d). 透明背景

2. 圖檔內容:
categories-35.png (35 * 35)

categories-35@2x.png (70 * 70)

buy-45.png (45 * 45)

buy-45@2x.png (90 * 90)

info-35.png (35 * 35)

info-35@2x.png (70 * 70)

3. 加入圖檔到 images 群組.

記得勾選: Copy items into destination group's folder

E. 增加 Categories(筆記本分類) 頁籤:
   1. 專案目錄 > New File: 

   2. iOS > Cocoa Touch > UIViewController subclass > Next

   3. Subclass 選擇: UITableViewController,
      並勾選(預設): With XIB for user interface > Next

   4. Save As: NoteBookViewController.m

   5. 開啟 NoteBookViewController.m 檔案, 修改三個 method:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    // Return the number of sections.
    //return 0;
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    // Return the number of rows in the section.
    //return 0;
    return 1;
}

- (id)initWithStyle:(UITableViewStyle)style
{    
    self = [super initWithStyle:style];
    if (self) {
        // Custom initialization
        self.title = @"Categories";
    }
    return self;
}

   6. 開啟 Lala_s_Program_NoteAppDelegate.m 檔案, 修改如下:
      a. import NoteBookViewController.h
         #import "NoteBookViewController.h"

      b. 修改: application: didFinishLaunchingWithOptions: 方法如下:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Override point for customization after application launch.
    tabBarController = [[UITabBarController alloc] init];
   
    /* Detect retina screen */
    BOOL hasHighResScreen = NO;
    if ([UIScreen instancesRespondToSelector:@selector(scale)]) {
        CGFloat scale = [[UIScreen mainScreen] scale];
        if (scale > 1.0) {
            hasHighResScreen = YES;
        }
    }
   
    /* ImageName */
    NSString *categoriesImageName = nil;
    NSString *purchaseImageName = nil;
    NSString *infoImageName = nil;
    if (hasHighResScreen) {
        categoriesImageName = @"categories-35@2x";
        purchaseImageName = @"buy-45@2x";
        infoImageName = @"info-35@2x";
    }
    else {
        categoriesImageName = @"categories-35";
        purchaseImageName = @"buy-45";
        infoImageName = @"info-35";
    } 

    /* A. for NoteBookViewController */
    // 1. Create a instance of NoteBookViewController
    NoteBookViewController *noteBookViewController = [[NoteBookViewController alloc] initWithStyle:UITableViewStylePlain];
    
    // 2. Create a instance of UITabBarItem
    UITabBarItem *noteBookItem = [[UITabBarItem alloc] initWithTitle:@"Categories" image:[UIImage imageNamed:categoriesImageName] tag:0];
    noteBookViewController.tabBarItem = noteBookItem;
    categoriesImageName = nil;
    [noteBookItem release];

    // 3. Wrap it in an instance of UINavigationController
    UINavigationController *navNoteController = [[[UINavigationController alloc] initWithRootViewController:noteBookViewController] autorelease];
   
    // 4. Release it
    [noteBookViewController release];
   
    // 5. Add it to the tab abr controller
    [tabBarController setViewControllers:[NSArray arrayWithObjects:navNoteController, nil]];
   
    [self.window addSubview:tabBarController.view];
   
    [self.window makeKeyAndVisible];
    return YES;
}


   7. 結果如下:

F. 增加 Favorite(我的最愛 ) 頁籤:
   1. 同 E. 1 ~ 4 之步驟, 檔名取為: FavoriteViewController.m 

   2. 開啟 FavoriteViewController.m 檔案, 修改三個 method:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    // Return the number of sections.
    //return 0;
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    // Return the number of rows in the section.
    //return 0;
    return 1;
}

- (id)initWithStyle:(UITableViewStyle)style
{   
    self = [super initWithStyle:style];
    if (self) {
        // Custom initialization
        self.title = @"Favorite";
    }
    return self; 
 }


   3. 開啟 Lala_s_Program_NoteAppDelegate.m 檔案, 修改如下:
     a. import FavoriteViewController.h
         #import "FavoriteViewController.h"

      b. 修改: application: didFinishLaunchingWithOptions: 方法如下:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Override point for customization after application launch.
    /*B. for FavoriteViewController */
    // 1. Create a instance of NoteBookViewController
    FavoriteViewController *favoriteViewController = [[FavoriteViewController alloc] initWithStyle:UITableViewStylePlain];
   
    // 2. Create a instance of UITabBarItem
    UITabBarItem *favoriteItem = [[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemFavorites tag:1];
    favoriteViewController.tabBarItem = favoriteItem;
    [favoriteItem release]; 

    // 3. Wrap it in an instance of UINavigationController
    UINavigationController *navFavoriteController = [[[UINavigationController alloc] initWithRootViewController:favoriteViewController] autorelease];
   
    // 4. Release it
    [favoriteViewController release];
   
    // 5. Add it to the tab abr controller
    [tabBarController setViewControllers:[NSArray arrayWithObjects:navNoteController, navFavoriteController, nil]];
   
    [self.window addSubview:tabBarController.view];
   
    [self.window makeKeyAndVisible];
    return YES;
}
   4. 結果如下:

G. 增加 Search(搜尋) 頁籤:
   1. 同 E. 1 ~ 4 之步驟(Subclass 選擇: UIViewController),
      檔名取為: SearchViewController.m 

   2. 開啟 SearchViewController.m 檔案, 修改如下:
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
        //@add
        self.title = @"Search";
    }
    return self;
}


   3. 開啟 Lala_s_Program_NoteAppDelegate.m 檔案, 修改如下:
     a. import SearchViewController.h
         #import "SearchViewController.h"

      b. 修改: application: didFinishLaunchingWithOptions: 方法如下:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Override point for customization after application launch.
    /* C. for SearchViewController */
    // 1. Create a instance of SearchViewController
    SearchViewController *searchViewController = [[SearchViewController alloc] init];
   
    // 2. Create a instance of UITabBarItem
    UITabBarItem *searchItem = [[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemSearch tag:2];
    searchViewController.tabBarItem = searchItem;
    [searchItem release];

    // 3. Wrap it in an instance of UINavigationController
    UINavigationController *navSearchController = [[[UINavigationController alloc] initWithRootViewController:searchViewController] autorelease];

    // 4. Release it
    [searchViewController release];


    // 5. Add it to the tab abr controller
    [tabBarController setViewControllers:[NSArray arrayWithObjects:navNoteController, navFavoriteController, navSearchController, nil]];
   
    ....


    [self.window addSubview:tabBarController.view];
   
    [self.window makeKeyAndVisible];
    return YES;
}


   4. 結果如下:

H. 增加 Purchase(購買) 頁籤:
   1. 同 E. 1 ~ 4 之步驟, 其中 Subclass 選擇: UIViewController, 檔名取為: PurchaseViewController.m 


   2. 開啟 Lala_s_Program_NoteAppDelegate.m 檔案, 修改如下:
     a. import PurchaseViewController.h
         #import "PurchaseViewController.h"

      b. 修改: application: didFinishLaunchingWithOptions: 方法如下:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Override point for customization after application launch.
    /* D. for PurchaseViewController */
    // 1. Create a instance of PurchaseViewController
    PurchaseViewController *purchaseViewController = [[PurchaseViewController alloc] init];    
   
    // 2. Create a instance of UITabBarItem
    UITabBarItem *purchaseItem = [[UITabBarItem alloc] initWithTitle:@"Buy" image:[UIImage imageNamed:purchaseImageName] tag:3];
    purchaseViewController.tabBarItem = purchaseItem;
    purchaseImageName = nil;
    [purchaseItem release];  

    // 3. Add it to the tab abr controller
    [tabBarController setViewControllers:[NSArray arrayWithObjects:navNoteController, navFavoriteController, navSearchController, purchaseViewController, nil]];
   
    // 4. Release it
    [purchaseViewController release];

    [self.window addSubview:tabBarController.view];
   
    [self.window makeKeyAndVisible];
    return YES;
}


   4. 結果如下:

I. 增加 Info(資訊) 頁籤:
   1. 同 E. 1 ~ 4 之步驟, 其中 Subclass 選擇: UIViewController, 檔名取為: InfoViewController.m 


   2. 開啟 Lala_s_Program_NoteAppDelegate.m 檔案, 修改如下:
     a. import InfoViewController.h
         #import "InfoViewController.h"

      b. 修改: application: didFinishLaunchingWithOptions: 方法如下:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Override point for customization after application launch.
    /* E. for InfoViewController */
    // 1. Create a instance of InfoViewController
    InfoViewController *infoViewController = [[InfoViewController alloc] init];    
   
    // 2. Create a instance of UITabBarItem
    UITabBarItem *infoItem = [[UITabBarItem alloc] initWithTitle:@"Info" image:[UIImage imageNamed:infoImageName] tag:4];
    infoViewController.tabBarItem = infoItem;
    infoImageName = nil;
    [infoItem release]; 

    // 3. Add it to the tab abr controller
    [tabBarController setViewControllers:[NSArray arrayWithObjects:navNoteController, navFavoriteController, navSearchController, purchaseViewController, infoViewController, nil]];
   
    // 4. Release it
    [infoViewController release];

    [self.window addSubview:tabBarController.view]; //@add
   
    [self.window makeKeyAndVisible];
    return YES;
}


   4. 結果如下:

=================================================================

使用 Interface Builder 的相關參考: (在這邊未使用到)

1. 修改 Tab Bar Item 屬性.

a. 屬性欄位說明:
(a). Badge (標記):可放置紅色圖示來顯示數目.
(b). Identifier:
- 選擇標準項目(Favorites, Search ....), 自動設定好Title 與 Image 欄位值.
- Custom: 可自定 Title 與 Image 欄位.
(c). Title: Tab Bar Item 的文字標題.
(d). Image: Tab Bar Item 的圖檔.

b. 在這裡, 除了 Favorites 與 Search 使用標準項目, 其餘的
Categories, Buy 與 Info 皆採用 Custom 的方式, 因此要自行提供圖檔.

2. 設定每個 Tab Bar 的 View Controller 屬性.

a. Title: 留白(Tab Bar Controller 不會用到)
b. Layout: Wants Full Screen(全螢幕), 不需勾選
c. NIB Name: 指定 NIB Name (不需加上 .xib 副檔名)
d. Resize View From NIB: 縮放 View (保留此設定)