ios coredata sqlite3 NSFetchedResultsController(2)

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//
//  RootViewController.m
//  FetchedResultsController
//
//  Created by 何瑾 on 15/1/16.
//  Copyright (c) 2015年 e世雕龙. All rights reserved.
//#import "RootViewController.h"
#import "Student.h"@interface RootViewController ()@property (strong, nonatomic) NSManagedObjectContext *managedObjectContext;// 托管对象上下文
@property (strong, nonatomic) NSFetchedResultsController *fetchedResultsController;// 抓取结果控制器@end@implementation RootViewController- (void)viewDidLoad {[super viewDidLoad];// 1、获取应用程序对象(单例)UIApplication *app = [UIApplication sharedApplication];// 2、获取应用程序委托id appDelegate = app.delegate;// 3、获取托管对象上下文self.managedObjectContext = [appDelegate managedObjectContext];// 4、创建抓取请求对象NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName:@"Student"];// 4.1、创建排序规则NSSortDescriptor *sd1 = [NSSortDescriptor sortDescriptorWithKey:@"name" ascending:YES];// 4.2、设置抓取请求对象的排序规则属性[request setSortDescriptors:@[sd1]];// 5、创建抓取结果控制器(1、给表视图提供数据。2、监控CoreData数据变化，回调四个委托方法)self.fetchedResultsController = [[NSFetchedResultsController alloc]initWithFetchRequest:request managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:@"stu"];// 5.1指定抓取结果控制器的委托，在CoreData中对象发生变化时调用相关委托方法self.fetchedResultsController.delegate = self;// 6、执行抓取__autoreleasing NSError *error = nil;[self.fetchedResultsController performFetch:&error];if (error) {[self myAlert:[error localizedDescription]];}
}#pragma mark 通过CoreData添加对象
- (IBAction)addObject:(id)sender {//使用实体描述对象把一个空的数据模型（托管对象）放入托管对象上下文中Student *stu = [NSEntityDescription insertNewObjectForEntityForName:@"Student" inManagedObjectContext:self.managedObjectContext];//设置托管对象属性值static int i = 0;i++;stu.name = [NSString stringWithFormat:@"何瑾%d",i];stu.phoneNumber = @18888888888;//保存托管对象上下文__autoreleasing NSError *error = nil;[self.managedObjectContext save:&error];if (error) {NSLog(@"%@",[error localizedDescription]);[self myAlert:[error localizedDescription]];}
}#pragma mark - Table view data source- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {return [[self.fetchedResultsController sections] count];
}- (NSInteger)tableView:(UITableView *)table numberOfRowsInSection:(NSInteger)section {if ([[self.fetchedResultsController sections] count] > 0) {id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section];return [sectionInfo numberOfObjects];} elsereturn 0;
}- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {// 创建出列可重用标识符static NSString *cellID = @"cellID";// 从出列可重用队列中获取单元格UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellID];// 如果没有则创建if (!cell) {cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:cellID];}Student *stu = [self.fetchedResultsController objectAtIndexPath:indexPath];// Configure the cell with data from the managed object.cell.textLabel.text = stu.name;cell.detailTextLabel.text = [stu.phoneNumber stringValue];return cell;
}/*
// 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// 只需要删除CoreData中对象// 从CoreData的托管对象上下文中获取模型对象Student *stu = [self.fetchedResultsController objectAtIndexPath:indexPath];// 从CoreData的托管对象上下文中删除对象[self.managedObjectContext deleteObject:stu];// 保存上下文__autoreleasing NSError *error = nil;[self.managedObjectContext save:&error];if (error) {[self myAlert:[error localizedDescription]];}} 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 - Navigation// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {// Get the new view controller using [segue destinationViewController].// Pass the selected object to the new view controller.
}
*/
#pragma Table view delegate
- (NSString *)tableView:(UITableView *)tableView titleForDeleteConfirmationButtonForRowAtIndexPath:(NSIndexPath *)indexPath {return @"删除";
}
#pragma mark 封装UIAlertView
- (void)myAlert:(NSString *)errorMsg {UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"信息" message:errorMsg delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil];[alert show];
}
#pragma mark NSFetchedResultsControllerDelegate methods
/*Assume self has a property 'tableView' -- as is the case for an instance of a UITableViewControllersubclass -- and a method configureCell:atIndexPath: which updates the contents of a given cellwith information from a managed object at the given index path in the fetched results controller.*/
// 告知tableView开始进行数据变化，此时tableView将会记录变化点，当所有变化结束之后，统一进行UI的刷新
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {[self.tableView beginUpdates];
}// 表视图分区变化回调此委托方法
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfoatIndex:(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;}
}// 根据CoreData数据变化类型进行表视图更新（增、删、改、移动）
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObjectatIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)typenewIndexPath:(NSIndexPath *)newIndexPath {UITableView *tableView = self.tableView;switch(type) {// 增加case NSFetchedResultsChangeInsert:[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];break;// 删除case NSFetchedResultsChangeDelete:[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]withRowAnimation:UITableViewRowAnimationFade];break;// 修改case NSFetchedResultsChangeUpdate:[tableView reloadRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];break;// 移动case NSFetchedResultsChangeMove:[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]withRowAnimation:UITableViewRowAnimationFade];[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];break;}
}// 通知tableView数据变化结束，开始进行UI刷新
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {[self.tableView endUpdates];
}
@end

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