NSFetchedResultsController * fetch;    AppDelegate * delegate=[UIapplication sharedApplication].delegate;            //獲取上下文    NSManagedObjectContext * context=[delegate.rosterStorage mainThreadManagedObjectContext];        //獲取請(qǐng)求NSFetchRequest    NSFetchRequest * request=[NSFetchRequest fetchRequestWithEntityName:@"XMPPUserCoreDataStorageObject"];        //增加排序字段    NSSortDescriptor * des=[NSSortDescriptor sortDescriptorWithKey:@"sectionNum" ascending:YES];    [request setSortDescriptors:@[des]];        //對(duì)fetch進(jìn)行初始化    fetch=[[NSFetchedResultsController alloc] initWithFetchRequest:request managedObjectContext:context sectionNameKeyPath:@"sectionNum" cacheName:nil];        //設(shè)置代理    [fetch setDelegate:self];        //開始查詢    [fetch performFetch:nil];

#pragma mark - Table view data source- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {    return fetch.sections.count;}- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {     id<NSFetchedResultsSectionInfo> sections=fetch.sections[section];    return [sections numberOfObjects] ;}- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"tabble" ];     XMPPUserCoreDataStorageObject * user=[fetch objectAtIndexPath:indexPath];    cell.textLabel.text=user.displayName;            return cell;}//返回分組數(shù)據(jù)信息，根據(jù)字段type來控制當(dāng)前的狀態(tài)-(NSString *) tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section{      id<NSFetchedResultsSectionInfo> info= [[fetch sections] objectAtIndex:section];    NSString * type=nil;        if ([info.name isEqualToString:@"0"]) {        type=@"在線";    }else {         type=@"離線";    }        return type;}

-(BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath{    return YES;}//通過花名冊(cè)對(duì)象對(duì)當(dāng)前的好友進(jìn)行刪除操作-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath{    if (editingStyle==UITableViewCellEditingStyleDelete) {        AppDelegate * delegate=[UIApplication sharedApplication] .delegate;                XMPPUserCoreDataStorageObject * user=[fetch objectAtIndexPath:indexPath];                [delegate.roster removeUser:user.jid];            }}

- (IBAction)add {    //獲取好友名稱    NSString * name=self.friends.text;     //獲取好友名稱    AppDelegate * delegate=[UIApplication sharedApplication].delegate;    XMPPJID * jid=[XMPPJID jidWithString:name];    if ([delegate.rosterStorage userExistsWithJID:jid xmppStream:delegate.stream]) {        NSLog(@"好友已經(jīng)存在了");    }else{        //增加好友        [delegate.roster subscribePresenceToUser:jid];    }}