update: 2011/09/22
A. 新增 "新增與編輯" 的介面:
1. 專案目錄 > New File >
2. iOS > Cocoa Touch > UIViewController subclass > Next >
3. Subclass 選擇: UIViewController, 並勾選(預設): With XIB for user interface > Next
4. Save As: ManageArticleViewController.m
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B. 開啟 ManageArticleViewController.h 修改如下:
#import <UIKit/UIKit.h>
#import <CoreData/CoreData.h>
@class ArticleListViewController; // 要當作 parenet Controller
@interface ManageArticleViewController : UIViewController {
IBOutlet UITextField *titleField; // article 標題
IBOutlet UITextField *subTitleField; // article 副標題
IBOutlet UITextView *contentText; // article 內容
ArticleListViewController *parenetController; // A poniter to parent controller
NSManagedObject *article; // represents the current note
}
@property (nonatomic, retain) IBOutlet UITextField *titleField;
@property (nonatomic, retain) IBOutlet UITextField *subTitleField;
@property (nonatomic, retain) IBOutlet UITextView *contentText;
@property (nonatomic, retain) ArticleListViewController *parenetController;
@property (nonatomic, retain) NSManagedObject *article;
- (id)initWithParentController:(ArticleListViewController *)aParentController article:(NSManagedObject *)anArticle;
- (IBAction)save:(id)sender;
- (IBAction)cancel:(id)sender;
- (IBAction)didEndEdit:(id)sender;
- (IBAction)hitBackground:(id)sender;
@end
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C. 開啟 ManageArticleViewController.m 修改如下:
#import "ManageArticleViewController.h"
#import "ArticleListViewController.h"
@synthesize titleField, subTitleField, contentText, parenetController, article;
- (IBAction)didEndEdit:(id)sender {
// 放棄成為第一回應者（鍵盤消失）
[sender resignFirstResponder];
}
- (IBAction)hitBackground:(id)sender {
//放棄成為第一回應者（鍵盤消失）
[titleField resignFirstResponder];
[subTitleField resignFirstResponder];
[contentText resignFirstResponder];
}
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- (id)initWithParentController:(ArticleListViewController *)aParentController article:(NSManagedObject *)anArticle
{
if ((self = [super init])) {
self.parenetController = aParentController;
self.article = anArticle;
}
return self;
}
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- (IBAction)save:(id)sender {
if (parenetController != nil) {
/* editing */
if (article != nil) {
[article setValue:titleField.text forKey:@"title"];
[article setValue:subTitleField.text forKey:@"subTitle"];
[article setValue:contentText.text forKey:@"content"];
//now date
[article setValue:[NSDate date] forKey:@"dateUpdate"];
// Save the context
[parenetController saveContext];
}
/* creating a new article */
else {
[parenetController insertArticleWithTitle:titleField.text subTitle:subTitleField.text content:contentText.text];
}
}
[self dismissModalViewControllerAnimated:YES];
}
- (IBAction)cancel:(id)sender {
[self dismissModalViewControllerAnimated:YES];
}
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- (void)dealloc {
[parenetController release];
[article release];
[super dealloc];
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
if (article != nil) {
titleField.text = [article valueForKey:@"title"];
subTitleField.text = [article valueForKey:@"subTitle"];
contentText.text = [article valueForKey:@"content"];
}
else {
}
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
self.titleField = nil;
self.subTitleField = nil;
self.contentText = nil;
}
D. 建立實際的 UI:
1. 拖拉一個 Navigation Bar 到 view 上, 對齊 view 最上方的中間,
將 title 改為: Article.
2. 拖拉二個 Bar Button Item 到 Navigation Bar 上, 一個放在左邊, 一個放在右邊.
(1). 分別更改它們的 label, 左邊為: Canel, 右邊為: Save
(2). 並分別與 File's Owner 上的 cancel: 與 save: 作連結.
3. 拖拉一個 Label 到 view 的左上方, Navigation Bar 的下面, 將其 text 改為: title:
4. 拖拉一個 TextField 到 title: Label 的右方, 並與 File's Owner
上的 titleField 作連結.
5. 拖拉一個 Label 到 title: Label 的下方, 將其 text 改為: subTitle:
6. 拖拉一個 TextField 到 subTitle: Label 的右方, 並與 File's Owner
上的 subTitleField 作連結.
7. 拖拉一個 Label 到 subTitle: Label 的下方, 將其 text 改為: content:
8. 拖拉一個 TextView 到 content: Label 的下方, 並與 File's Owner
上的 contentText 作連結.
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E. 開啟 ArticleListViewController.h 檔案, 新增二個 method 如下:
- (void)showManageArticleView;
- (void)insertArticleWithTitle:(NSString *)title subTitle:(NSString *)subTitle content:(NSString *)content;
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F. 開啟 ArticleListViewController.m 檔案, 新增二個 method 如下:
#import "ArticleListViewController.h"
#import "ManageArticleViewController.h"
- (void)showManageArticleView {
ManageArticleViewController *manageArticleViewController = [[ManageArticleViewController alloc]initWithParentController:self article:nil]; // so a new Article will be created
[self presentModalViewController:manageArticleViewController animated:YES];
[manageArticleViewController release];
}
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- (void)insertArticleWithTitle:(NSString *)title subTitle:(NSString *)subTitle content:(NSString *)content {
NSManagedObjectContext *context = [fetchedResultsController managedObjectContext];
NSEntityDescription *entity = [[fetchedResultsController fetchRequest] entity];
NSManagedObject *newArticle = [NSEntityDescription insertNewObjectForEntityForName:[entity name] inManagedObjectContext:context];
[newArticle setValue:title forKey:@"title"];
[newArticle setValue:subTitle forKey:@"subTitle"];
[newArticle setValue:content forKey:@"content"];
//Date
[newArticle setValue:[NSDate date] forKey:@"dateCreated"];
[newArticle setValue:[NSDate date] forKey:@"dateUpdate"];
//[self.noteBook setValue:newArticle forKey:@"articles"];
// 'NSInvalidArgumentException', reason: 'Unacceptable type of value for to-many relationship: property = "articles"; desired type = NSSet; given type = NSManagedObject;
//@use NSSet to handle to-many relationship
NSMutableSet *articles = [self.noteBook mutableSetValueForKey:@"articles"];
[articles addObject:newArticle];
// Save the context
[self saveContext];
}
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G. 幫 ArticleList 介面增加 "新增" 與 "編輯" 的按鈕.
開啟 ArticleListViewController.m 檔案, 修改如下:
- (void)viewDidLoad
{
[super viewDidLoad];
// Uncomment the following line to preserve selection between presentations.
// self.clearsSelectionOnViewWillAppear = NO;
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem;
//@add 編輯按鈕 (實際上是進入刪除的功能)
// 在此處, 會讓 navigation bar 的回上頁消失 (之後再處理 "刪除" 功能)
//self.navigationItem.leftBarButtonItem = self.editButtonItem;
//@add 新增按鈕
UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(showManageArticleView)];
self.navigationItem.rightBarButtonItem = addButton;
[addButton release];
}
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H. 增加: 編輯 Article 功能:
開啟 ArticleListViewController.m 檔案, 修改如下:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// Navigation logic may go here. Create and push another view controller.
/*
<#DetailViewController#> *detailViewController = [[<#DetailViewController#> alloc] initWithNibName:@"<#Nib name#>" bundle:nil];
// ...
// Pass the selected object to the new view controller.
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController release];
*/
NSManagedObject *article = [[self fetchedResultsController] objectAtIndexPath:indexPath];
ManageArticleViewController *manageArticleViewController = [[ManageArticleViewController alloc] initWithParentController:self article:article];
[self presentModalViewController:manageArticleViewController animated:YES];
[manageArticleViewController release];
}
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I. UITextField 輸入結束後, 收起小鍵盤.
開啟 ManageArticleViewController.xib 檔案:
將 File's Owner 裡的 didEndEdit: mehod 分別與 UI 的二個 Text Field "Did End On Exit" 做連結.
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J. 點擊 UITextField 輸入的背景收起小鍵盤.
開啟 ManageArticleViewController.xib 檔案:
(1). 將 UIView 的 Class 設定成 UIControl,
只有 UIControl Class 的控制項才可以觸發動作.
(2). 將 File's Owner 裡的 hitBackground: mehod
與剛剛的 UIControl 裡的 Touch Up Inside 作連結.
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K. 結果圖:
1. 瀏覽文章列表:
NoteBook:
NoteBook: Relationships -> articles (NoteArticle)
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