ios coredata sqlite3 NSFetchedResultsController(2)

////  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];    } else        return 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 UITableViewController subclass -- and a method configureCell:atIndexPath: which updates the contents of a given cell with 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>)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;    }}// 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)anObject       atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type      newIndexPath:(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