//使用CoreData获取数据
    // 1.上下文【关联到数据库XMPPRoster.sqlite】
    NSManagedObjectContext *context = [WCXMPPTool sharedWCXMPPTool].rosterStorage.mainThreadManagedObjectContext;

    // 2.FetchRequest【查哪张表】
    NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName:@"XMPPUserCoreDataStorageObject"];

    // 3.设置过滤和排序
    // 过滤当前登录用户的好友
    NSString *jid = [WCUserInfo sharedWCUserInfo].jid;
    NSPredicate *pre = [NSPredicate predicateWithFormat:@"streamBareJidStr = %@",jid];
    request.predicate = pre;

    //排序
    NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:@"displayName" ascending:YES];
    request.sortDescriptors = @[sort];

    // 4.执行请求获取数据
    _resultsContrl = [[NSFetchedResultsController alloc] initWithFetchRequest:request managedObjectContext:context sectionNameKeyPath:nil cacheName:nil];

    _resultsContrl.delegate = self;

    NSError *err = nil;
    [_resultsContrl performFetch:&err];
    if (err) {
        WCLog(@"%@",err);
    }

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
    return _resultsContrl.fetchedObjects.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *ID = @"ContactCell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:ID];

    // 获取对应好友
    //XMPPUserCoreDataStorageObject *friend =self.friends[indexPath.row];
    XMPPUserCoreDataStorageObject *friend = _resultsContrl.fetchedObjects[indexPath.row];
    //    sectionNum
    //    “0”- 在线
    //    “1”- 离开
    //    “2”- 离线
    switch ([friend.sectionNum intValue]) {//好友状态
        :
            cell.detailTextLabel.text = @"在线";
            break;
        :
            cell.detailTextLabel.text = @"离开";
            break;
        :
            cell.detailTextLabel.text = @"离线";
            break;
        default:
            break;
    }
    cell.textLabel.text = friend.jidStr;

    return cell;
}

#pragma mark 当数据的内容发生改变后，会调用 这个方法
-(void)controllerDidChangeContent:(NSFetchedResultsController *)controller{
    WCLog(@"数据发生改变");
    //刷新表格
    [self.tableView reloadData];
}

//实现这个方法，cell往左滑就会有个delete
-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath{
    if (editingStyle == UITableViewCellEditingStyleDelete) {
        WCLog(@"删除好友");
        XMPPUserCoreDataStorageObject *friend = _resultsContrl.fetchedObjects[indexPath.row];

        XMPPJID *freindJid = friend.jid;
        [[WCXMPPTool sharedWCXMPPTool].roster removeUser:freindJid];
    }
}

#import "WCAddContactViewController.h"

@interface WCAddContactViewController()<UITextFieldDelegate>

@end

@implementation WCAddContactViewController

-(BOOL)textFieldShouldReturn:(UITextField *)textField{
    // 添加好友

    // 1.获取好友账号
    NSString *user = textField.text;
    WCLog(@"%@",user);

    // 判断这个账号是否为手机号码
    if(![textField isTelphoneNum]){
        //提示
        [self showAlert:@"请输入正确的手机号码"];
        return YES;
    }

    //判断是否添加自己
    if([user isEqualToString:[WCUserInfo sharedWCUserInfo].user]){

        [self showAlert:@"不能添加自己为好友"];
        return YES;
    }
    NSString *jidStr = [NSString stringWithFormat:@"%@@%@",user,domain];
    XMPPJID *friendJid = [XMPPJID jidWithString:jidStr];

    //判断好友是否已经存在
    if([[WCXMPPTool sharedWCXMPPTool].rosterStorage userExistsWithJID:friendJid xmppStream:[WCXMPPTool sharedWCXMPPTool].xmppStream]){
        [self showAlert:@"当前好友已经存在"];
        return YES;
    }

    // 2.发送好友添加的请求
    // 添加好友,xmpp有个叫订阅

    [[WCXMPPTool sharedWCXMPPTool].roster subscribePresenceToUser:friendJid];

    return YES;
}

-(void)showAlert:(NSString *)msg{

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"温馨提示" message:msg delegate:nil cancelButtonTitle:@"谢谢" otherButtonTitles:nil, nil];
    [alert show];
}
@end