iphone开发 IOS中CoreData的通用代码

GoupTableViewController.h文件
#import <UIKit/UIKit.h>
#import "StudentTableViewController.h"
#import "addTableViewController.h"
#import "Group.h"
@interface GoupTableViewController : UITableViewController<NSFetchedResultsControllerDelegate>
@property(retain,nonatomic) NSManagedObjectContext *managedObjectContext;
@property(retain,nonatomic)NSFetchedResultsController *fetchedResultsController;
@end

GoupTableViewController.m文件
#import "GoupTableViewController.h"
@interface GoupTableViewController ()
@end
@implementation GoupTableViewController
@synthesize managedObjectContext;
@synthesize fetchedResultsController= _fetchedResultsController;
- (id)initWithStyle:(UITableViewStyle)style
{
    self = [super initWithStyle:style];
    if (self) {
        id delegate=[[UIApplication sharedApplication]delegate];
        self.managedObjectContext=[delegate managedObjectContext];
    }
    return self;
}
- (void)viewDidLoad
{
    [super viewDidLoad];
    self.navigationItem.title=@"ios44班";
    UIBarButtonItem *addButton=[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(addGroup)];
    self.navigationItem.rightBarButtonItem = addButton;
    [addButton release];
    self.navigationItem.leftBarButtonItem = self.editButtonItem;
}
-(void)addGroup
{
    addTableViewController *add=[[addTableViewController alloc]init];
    [self.navigationController pushViewController:add animated:YES];
    [add release];
}
- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return [[self.fetchedResultsController sections] count];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    id<NSFetchedResultsSectionInfo> sectionInfo=[[self.fetchedResultsController sections] objectAtIndex:section];
    return [sectionInfo numberOfObjects];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier] autorelease];
        cell.accessoryType=UITableViewCellAccessoryDisclosureIndicator;
    }
   [self configureCell:cell atIndexPath:indexPath];
    return cell;
}
-(void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
    NSManagedObject *managedObject=[self.fetchedResultsController objectAtIndexPath:indexPath];
    cell.textLabel.text=[[managedObject valueForKey:@"title"] description];
    cell.detailTextLabel.textColor=[UIColor greenColor];
    cell.detailTextLabel.text=[NSString stringWithFormat:@"第%d组",[[managedObject valueForKey:@"num"] intValue]];
}
-(NSFetchedResultsController *)fetchedResultsController
{
    if (_fetchedResultsController!=nil)
    {
        return _fetchedResultsController;
    }
    NSFetchRequest *fetchRequest=[[NSFetchRequest alloc]init];
    NSEntityDescription *entity=[NSEntityDescription entityForName:@"Group" inManagedObjectContext:self.managedObjectContext];
    [fetchRequest setEntity:entity];
    [fetchRequest setFetchBatchSize:20];
    NSSortDescriptor *sortDescriptor=[[NSSortDescriptor alloc] initWithKey:@"num" ascending:YES];
    NSArray *sortArray=[NSArray arrayWithObjects:sortDescriptor, nil];
    [sortDescriptor release];
    [fetchRequest setSortDescriptors:sortArray];
    NSFetchedResultsController *afetchedResultsController=[[NSFetchedResultsController alloc]initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:@"Group"];
    [fetchRequest release];
    afetchedResultsController.delegate=self;
    self.fetchedResultsController=afetchedResultsController;
    [afetchedResultsController release];
    NSError *error;
    if (![self.fetchedResultsController performFetch:&error])
    {
        NSLog(@"获取信息失败,%@,%@",error,[error userInfo]);
        abort();
    }
    return _fetchedResultsController;
}
-(void)controllerWillChangeContent:(NSFetchedResultsController *)controller
{
    [self.tableView beginUpdates];
}
- (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;
    }
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
       atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
      newIndexPath:(NSIndexPath *)newIndexPath
{
    UITableView *tableView = self.tableView;
    switch(type)
    {
        case NSFetchedResultsChangeInsert:
            [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;
        case NSFetchedResultsChangeDelete:
            [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;
        case NSFetchedResultsChangeUpdate:
            [self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
            break;
        case NSFetchedResultsChangeMove:
            [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
            [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
            break;
    }
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
    [self.tableView endUpdates];
}
// Override to support conditional editing of the table view.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Return NO if you do not want the specified item to be editable.
    return YES;
}
// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (editingStyle == UITableViewCellEditingStyleDelete) {
        // Delete the row from the data source
        NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
        [context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]];
        NSError *error;
        if (![context save:&error]) {
            NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
            abort();
        }
    }  
    else if (editingStyle == UITableViewCellEditingStyleInsert) {
        // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
    }  
}
// Override to support rearranging the table view.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath
{
}
// Override to support conditional rearranging of the table view.
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Return NO if you do not want the item to be re-orderable.
    return YES;
}
#pragma mark - Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    StudentTableViewController *listStudent=[[StudentTableViewController alloc]init];
    listStudent.group=[self.fetchedResultsController objectAtIndexPath:indexPath];
    [self.navigationController pushViewController:listStudent animated:YES];
    [listStudent release];
}
@end