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CoreDataå®žä¾‹åˆ†æžå¦ä¹ ï¼ˆ2ï¼‰

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åœ¨æˆ‘ä»¬åˆ†æžäº†ç¨‹åºä¸»ä»£ç†æ–‡ä»¶ï¼ˆAppDelegateï¼‰ä¹‹åŽï¼Œæˆ‘ä»¬å…ˆæ¥çœ‹çœ‹ä¸€å¯¹è‡ªåŠ¨ç”Ÿæˆçš„æ–‡ä»¶Event.h/.m

@interface Event : NSManagedObject  {}
@property (nonatomic, retain) NSDate *creationDate;
@property (nonatomic, retain) NSNumber *latitude;
@property (nonatomic, retain) NSNumber *longitude;
@end

#import "Event.h"
@implementation Event
@dynamic creationDate;
@dynamic latitude;
@dynamic longitude;
@end

ä»Žä¸Šé¢æˆ‘ä»¬èƒ½çœ‹å‡ºæ¥ï¼Œä¸€ä¸ªå®žä½“Eventä¹Ÿå°±ä¼šè¢«ç”Ÿæˆä¸€ä¸ªNSManagedObjectï¼ˆè¢«ç®¡ç†å¯¹è±¡ï¼‰ï¼Œç„¶åŽä»»ä½•accessorå’Œgetter éƒ½æ˜¯è¢«åŠ¨æ€ç”Ÿæˆçš„ï¼Œæˆ‘ä»¬å…¶å®žå®Œå…¨ä¸ç”¨æ“ä»»ä½•çš„å¿ƒï¼Œåªéœ€è¦åœ¨xcdatamodelæ–‡ä»¶é‡Œé¢é…ç½®åŽï¼Œç‚¹å‡»æ·»åŠ æ–‡ä»¶ï¼Œæ·»åŠ NSManagedObjectæ–‡ä»¶ï¼Œå°±ä¼šçœ‹åˆ°è‡ªåŠ¨æ„ŸçŸ¥çš„ç±»å¯¹è±¡ï¼Œç„¶åŽç”Ÿæˆå°±å¯ä»¥äº†ã€‚

ä¸‹é¢æ˜¯æ ¹è§†å›¾æŽ§åˆ¶å™¨ï¼Œæ˜¯ä¸€ä¸ªåˆ—è¡¨è§†å›¾ï¼ˆUITableViewControllerï¼‰

#import <CoreLocation/CoreLocation.h>
@interface RootViewController : UITableViewController <CLLocationManagerDelegate> {
	//çœ‹åˆ°æ˜¯UITableViewControllerçš„åç±»ï¼Œç”±äºŽéœ€è¦ä½¿ç”¨Core Locationï¼Œ
	//æ‰€ä»¥åœ¨åŽé¢å±¥è¡Œå…¶protocal
    NSMutableArray *eventsArray;
	NSManagedObjectContext *managedObjectContext;
	//è¿™ä¸ªè¢«ç®¡ç†å¯¹è±¡å†…å®¹å™¨å°±æ˜¯æˆ‘ä»¬çœŸæ£å¯¹Core Dataæ•°æ®çš„æ“ä½œå¯¹è±¡
    CLLocationManager *locationManager; 	//ç”¨æ¥å¾—åˆ°åœ°ç†ä½ç½®çš„Core Locationå¯¹è±¡
    UIBarButtonItem *addButton;	//å³ä¸Šè§’çš„æ·»åŠ é”®
}
@property (nonatomic, retain) NSMutableArray *eventsArray;
@property (nonatomic, retain) NSManagedObjectContext *managedObjectContext;
@property (nonatomic, retain) CLLocationManager *locationManager;
@property (nonatomic, retain) UIBarButtonItem *addButton;
- (void)addEvent;
@end

#import "RootViewController.h"
#import "LocationsAppDelegate.h"
#import "Event.h"
@implementation RootViewController
@synthesize eventsArray, managedObjectContext, addButton, locationManager;
 
- (void)viewDidLoad {
    [super viewDidLoad];
    self.title = @"Locations"; //è®¾ç½®åˆ—è¡¨è§†å›¾çš„æ ‡é¢˜
    self.navigationItem.leftBarButtonItem = self.editButtonItem; //å¯¼èˆªæ å·¦è¾¹çš„ç¼–è¾‘æŒ‰é’®
 
    addButton = [[UIBarButtonItem alloc]
                initWithBarButtonSystemItem:UIBarButtonSystemItemAdd
                target:self
                action:@selector(addEvent)]; //åˆå§‹åŒ–æ·»åŠ æŒ‰é’®ï¼Œ
	addButton.enabled = NO; //åœ¨Core Locationåˆå§‹åŒ–ä¹‹å‰å°†å…¶å…³é—
    self.navigationItem.rightBarButtonItem = addButton;
    //æŠŠè¿™ä¸ªæ·»åŠ æŒ‰é’®æ·»åŠ åˆ°å¯¼èˆªæ å³ä¾§
 
	// å¯åŠ¨CLocation
	[[self locationManager] startUpdatingLocation];
 
        //åˆå§‹åŒ–ä¸€ä¸ªâ€œèŽ·å–è¯·æ±‚â€åˆ°æˆ‘ä»¬çš„å®žä½“â€œEventâ€
	NSFetchRequest *request = [[NSFetchRequest alloc] init];
	NSEntityDescription *entity = [NSEntityDescription entityForName:@"Event" 
			inManagedObjectContext:managedObjectContext];
	[request setEntity:entity];
 
	// å°†æ—¶é—´ä»¥å»ºç«‹æ—¶é—´æŽ’åºï¼Œæœ€æ–°çš„åœ¨æœ€ä¸Š
	NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"creationDate" ascending:NO];
	NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
	[request setSortDescriptors:sortDescriptors];
	[sortDescriptor release];
	[sortDescriptors release];
 
	// æ‰§è¡Œâ€œèŽ·å–â€æ“ä½œï¼Œå¾—åˆ°ä¸€ä¸ªâ€œå¯å˜æ•°ç»„â€çš„æ‹·è´
	NSError *error = nil;
	NSMutableArray *mutableFetchResults = [[managedObjectContext 
				executeFetchRequest:request 
				error:&error] mutableCopy];
	if (mutableFetchResults == nil) {
		//å¦‚æžœç»“æžœä¸ºç©ºï¼Œåœ¨è¿™ä½œé”™è¯¯å“åº”
	}
 
	// å°†å¾—åˆ°çš„æœ¬åœ°æ•°ç»„èµ‹å€¼åˆ°æœ¬ç±»çš„å…¨å±€æ•°ç»„ï¼Œç„¶åŽæ¸…ç†æ— ç”¨çš„å¯¹è±¡
	[self setEventsArray:mutableFetchResults];
	[mutableFetchResults release];
	[request release];
}
 
- (void)viewDidUnload {
	// å½“è§†å›¾è¢«å¸è½½åŽï¼Œå°†ä»¥ä¸‹æŒ‡é’ˆç½®ç©º
	self.eventsArray = nil;
	self.locationManager = nil;
	self.addButton = nil;
}
 
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
	// åªæœ‰ä¸€ä¸ªç« èŠ‚
    return 1;
}
 
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
	// åœ¨æ•°ç»„é‡Œé¢æœ‰å¤šå°‘ä¸ªå¯¹è±¡ï¼Œåœ¨åˆ—è¡¨è§†å›¾å°±æœ‰å¤šå°‘è¡Œ
    return [eventsArray count];
}
 
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
 
	// ä¸€ä¸ªâ€œæ—¥æœŸæ ¼å¼åŒ–å™¨â€ï¼ˆå‡‘åˆæ˜Žç™½å°±å¥½...ï¼‰ç”¨æ¥ä»¥ç‰¹å®šçš„æ ¼å¼åˆ›å»ºå¾—åˆ°çš„æ—¥æœŸ
    static NSDateFormatter *dateFormatter = nil;
	if (dateFormatter == nil) {
		dateFormatter = [[NSDateFormatter alloc] init];
		[dateFormatter setTimeStyle:NSDateFormatterMediumStyle];
		[dateFormatter setDateStyle:NSDateFormatterMediumStyle];
	}
 
	static NSNumberFormatter *numberFormatter = nil;
	if (numberFormatter == nil) {
		numberFormatter = [[NSNumberFormatter alloc] init];
		[numberFormatter setNumberStyle:NSNumberFormatterDecimalStyle];
		[numberFormatter setMaximumFractionDigits:3];
	}
 
    static NSString *CellIdentifier = @"Cell";
 
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle 
			reuseIdentifier:CellIdentifier] autorelease];
		UITableViewCellStyleSubtitle;
    }
 
	// ä»Žæ•°ç»„ä¸å¾—åˆ°è¿™ä¸ªEventå¯¹è±¡
	Event *event = (Event *)[eventsArray objectAtIndex:indexPath.row];
 
	cell.textLabel.text = [dateFormatter stringFromDate:[event creationDate]];
 
	NSString *string = [NSString stringWithFormat:@"%@, %@",
						[numberFormatter stringFromNumber:[event latitude]],
						[numberFormatter stringFromNumber:[event longitude]]];
    cell.detailTextLabel.text = string;
 
	return cell;
}
 
- (void)tableView:(UITableView *)tableView 
	commitEditingStyle:(UITableViewCellEditingStyle)editingStyle 
	forRowAtIndexPath:(NSIndexPath *)indexPath 
{
 
    if (editingStyle == UITableViewCellEditingStyleDelete) {
 
        // åˆ é™¤è¢«æƒ¯ä¾‹å¯¹è±¡åœ¨ç´¢å¼•è·¯å¾„ï¼ˆindex pathï¼‰
		NSManagedObject *eventToDelete = [eventsArray objectAtIndex:indexPath.row];
		[managedObjectContext deleteObject:eventToDelete];
 
	// æ›´æ–°æ•°ç»„å’Œåˆ—è¡¨è§†å›¾
        [eventsArray removeObjectAtIndex:indexPath.row];
        [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:YES];
 
		// æäº¤æ›´æ”¹åˆ°Core Data
		NSError *error;
		if (![managedObjectContext save:&error]) {
			// Handle the error.
		}
    }
}
 
- (void)addEvent {
	//å¦‚æžœå¾—ä¸åˆ°ä½ç½®ï¼Œå°±è¿”å›ž.
	CLLocation *location = [locationManager location];
	if (!location) {
		return; }
 
	 //å»ºç«‹ä¸€ä¸ªEventå®žä½“å¯¹è±¡
	Event *event = (Event *)[NSEntityDescription 
			insertNewObjectForEntityForName:@"Event" 
			inManagedObjectContext:managedObjectContext];
 
	//å¾—åˆ°ç»çº¬åº¦ï¼Œç„¶åŽèµ‹å€¼åˆ°eventå¯¹è±¡åŽ»
	CLLocationCoordinate2D coordinate = [location coordinate];
	[event setLatitude:[NSNumber numberWithDouble:coordinate.latitude]];
	[event setLongitude:[NSNumber numberWithDouble:coordinate.longitude]];
 
	// å®žä¾‹é‡Œé¢å¹¶æ²¡æœ‰ä½¿ç”¨CLçš„æ—¶é—´æ ‡ç¾ï¼Œå› ä¸ºåœ¨æ¨¡æ‹Ÿå™¨ä¸ä¼šæ˜¯ä¸€æ ·çš„
	// [event setCreationDate:[location timestamp]];
	[event setCreationDate:[NSDate date]]; 
	//æ‰€ä»¥çŽ°åœ¨ä½¿ç”¨çš„æ˜¯çŽ°åœ¨çš„æ—¶é—´ï¼Œè€Œä¸æ˜¯å¾—åˆ°ä½ç½®çš„æ—¶å€™çš„æ—¶é—´
 
	// ä¿å˜æ›´æ”¹
	NSError *error;
	if (![managedObjectContext save:&error]) {
		// Handle the error.
	}
 
	// å°†æ–°Eventæ”¾åˆ°æœ€ä¸Šé¢ï¼Œæ‰€ä»¥æ·»åŠ åˆ°0çš„ä½ç½®
	// ç„¶åŽæ»šåŠ¨åˆ—è¡¨è§†å›¾åˆ°æœ€ä¸Šé¢ï¼Œå¦‚æžœæ²¡æœ‰é‚£ä¹ˆå¤šçš„æ•°æ®æ˜¯çœ‹ä¸å‡ºæ¥åŒºåˆ«çš„
	[eventsArray insertObject:event atIndex:0];
	NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
	[self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] 
			withRowAnimation:UITableViewRowAnimationFade];
	[self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0] 
			atScrollPosition:UITableViewScrollPositionTop animated:YES];
}
 
- (CLLocationManager *)locationManager {
	//è‡ªå®šä¹‰çš„CLocationçš„getterï¼Œæ–¹ä¾¿åˆå§‹åŒ–
    if (locationManager != nil) {
		return locationManager;
	}
	//åˆå§‹åŒ–CLå¯¹è±¡ï¼Œç„¶åŽè®¾ç½®ç²¾å‡†åº¦ï¼Œç„¶åŽå°†ä»£ç†å¯¹è±¡è®¾ä¸ºæœ¬åœ°
	locationManager = [[CLLocationManager alloc] init];
	[locationManager setDesiredAccuracy:kCLLocationAccuracyNearestTenMeters];
	[locationManager setDelegate:self];
 
	return locationManager;
}
//CLocationçš„ä¸€ä¸ªä»£ç†æ–¹æ³•ï¼Œå¦‚æžœæˆåŠŸå°±å¼€å¯å³ä¾§æ·»åŠ æŒ‰é’®
- (void)locationManager:(CLLocationManager *)manager
    didUpdateToLocation:(CLLocation *)newLocation
           fromLocation:(CLLocation *)oldLocation {
    addButton.enabled = YES;
}
//CLocationçš„ä¸€ä¸ªä»£ç†æ–¹æ³•ï¼Œå¦‚æžœå¤±è´¥äº†å°±å…³é—ï¼ˆdisableï¼‰å³ä¾§æ·»åŠ æŒ‰é’®
- (void)locationManager:(CLLocationManager *)manager
       didFailWithError:(NSError *)error {
    addButton.enabled = NO;
}
 
- (void)dealloc {
	//é‡Šæ”¾å¯¹è±¡
	[managedObjectContext release];
	[eventsArray release];
    [locationManager release];
    [addButton release];
    [super dealloc];
}
@end

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