iOS 即時通訊系列之XMPP登入、註冊、聊天

時間 2019-11-17

原文原文鏈接

說明：在即時通訊系列XMPP之搭建本地服務器中闡述了經過XAMPP、Openfire工具搭建基於XMPP的服務器端，並使用spark軟件進行XMPP客戶端的調試。在本文中主要闡述將XMPP添加到工程中，實現iOS中基於XMPP的即時通訊。 ####項目環境配置使用CocoaPods導入XMPP框架，若是不會CocoaPods，點擊CocoaPods安裝及使用教程，或者手動導入XMPP框架。數據庫

####建立XMPP管理類爲了讓XMPP不會對工程中其它業務代碼具備侵入性，方便咱們管理整個關於XMPP的邏輯處理，一般會採用單例模式新建一個專門的管理類，爲此，在工程中建立一個繼承自NSObject的XMPPManger，爲了可以在代碼中方便調用XMPPStreamDelegate的方法，讓其遵照XMPPStreamDelegate協議。 XMPP框架中全部的鏈接、登入、註冊、受權、失去鏈接等操做的回調都是經過XMPPStream來管理，因此XMPPManger必須有一個XMPPStream實例。其它的還包括進行添加好友、刪除好友、獲取好友列表等功能的XMPPRoster；消息保存組件XMPPMessageArchiving等。數組

######XMPPManager.hbash

@interface XMPPManager : NSObject<XMPPStreamDelegate>

/**
 *  建立全局惟一的管理者對象
 *  @return 返回一個單例對象
 */
+ (XMPPManager *)sharedXMPPManager;

/**
 *  信息管道
 */
@property (nonatomic,strong)XMPPStream *stream;
/**
 *  進行添加好友 刪除好友 獲取好友列表等功能
 */
@property (nonatomic,strong)XMPPRoster *roster;
/**
 *  消息保存組件
 */
@property (nonatomic,strong)XMPPMessageArchiving *messageArchiving;
/**
 *  消息保存組件的CoreData上下文
 */
@property (nonatomic,strong)NSManagedObjectContext *managerObjectContext;
/**
 *  登入
 *
 *  @param userName 帳戶
 *  @param password 密碼
 */
- (void)loginWithUserName:(NSString *)userName password:(NSString *)password;
/**
 *  註冊
 *
 *  @param userName 帳戶
 *  @param password 密碼
 */
- (void)registWithUserName:(NSString *)userName password:(NSString *)password;

@end
複製代碼

######XMPPManager.m服務器

//服務器的地址
static NSString *const kHostName = @"127.0.0.1";
//端口號
static UInt16 const kHostPort = 5222;

//鏈接服務器類型
typedef NS_ENUM(NSUInteger,ConnectToServerStatus) {
    ConnectToServerStatusLogin,
    ConnectToServerStatusRegist,
};

@interface XMPPManager ()
//登入密碼
@property (nonatomic,strong)NSString *loginpassword;
//註冊密碼
@property (nonatomic,strong)NSString *registpassword;
//是登入仍是註冊
@property (nonatomic,assign)ConnectToServerStatus connectToSercerStatus;

@end

@implementation XMPPManager

+ (XMPPManager *)sharedXMPPManager{
    static XMPPManager *xmppManager = nil;
    static dispatch_once_t token;
    dispatch_once(&token, ^{
        xmppManager = [[XMPPManager alloc] init];
    });
    return xmppManager;
}

- (instancetype)init{
    if ([super init]) {
        //設置通訊管道屬性
        self.stream = [[XMPPStream alloc] init];
        self.stream.hostName = kHostName;
        self.stream.hostPort = kHostPort;
        //設置當前對象爲stream的代理
        [self.stream addDelegate:self delegateQueue:dispatch_get_main_queue()];
        
        //進行好友存儲
        XMPPRosterCoreDataStorage *rosterStorage = [XMPPRosterCoreDataStorage sharedInstance];
        self.roster = [[XMPPRoster alloc] initWithRosterStorage:rosterStorage dispatchQueue:dispatch_get_main_queue()];
        //激活
        [self.roster activate:self.stream];
        
        //進行聊天信息存儲
        XMPPMessageArchivingCoreDataStorage *messageArchivingStorage = [XMPPMessageArchivingCoreDataStorage sharedInstance];
        self.messageArchiving = [[XMPPMessageArchiving alloc] initWithMessageArchivingStorage:messageArchivingStorage dispatchQueue:dispatch_get_main_queue()];
        [self.messageArchiving activate:self.stream];
        
        self.managerObjectContext = messageArchivingStorage.mainThreadManagedObjectContext;
    }
    return self;
}

//與服務器創建連接
-(void)connectToServerWithUser:(NSString *)user{
    //要是正在連接的話那麼就先斷開鏈接
    if ([self.stream isConnected]) {
        [self disconnectServer];
    }
    XMPPJID *jid = [XMPPJID jidWithUser:user domain:@"DH_Fantasy" resource:@"iPhone"];
    self.stream.myJID = jid;
    NSError *error = nil;
    [self.stream connectWithTimeout:30.0f error:&error];
    if (nil != error) {
        NSLog(@"%s__%d__連接出錯：%@",__FUNCTION__,__LINE__,error);
    }
}

//與服務器斷開連接
-(void)disconnectServer{
    [self.stream disconnect];
}
//登入
- (void)loginWithUserName:(NSString *)userName password:(NSString *)password{
    self.connectToSercerStatus = ConnectToServerStatusLogin;
    self.loginpassword = password;//將傳進來的password傳給self.password
    [self connectToServerWithUser:userName];
}
//註冊
- (void)registWithUserName:(NSString *)userName password:(NSString *)password{
    self.connectToSercerStatus = ConnectToServerStatusRegist;
    self.registpassword = password;
    [self connectToServerWithUser:userName];
}

#pragma mark XMPPStreamDelegate
//與服務器連接成功
-(void)xmppStreamDidConnect:(XMPPStream *)sender{
#pragma mark 判斷與服務器創建鏈接是登錄仍是註冊
    switch (self.connectToSercerStatus) {
        case ConnectToServerStatusLogin:
        {
            NSError *error = nil;
            [self.stream authenticateWithPassword:self.loginpassword error:&error];
            if (nil != error) {
                NSLog(@"%s__%d__驗證出錯：%@",__FUNCTION__,__LINE__,error);
            }
            break;
        }
        case ConnectToServerStatusRegist:
        {
            NSError *err = nil;
            [self.stream registerWithPassword:self.registpassword error:&err];
            if (nil != err) {
                NSLog(@"%s__%d__註冊出錯：%@",__FUNCTION__,__LINE__,err);
            }
            break;
        }
        default:
            break;
    }
}
//與服務器連接失敗
-(void)xmppStreamConnectDidTimeout:(XMPPStream *)sender{
    NSLog(@"😂與服務器連接失敗");
}

- (void)xmppStreamWillConnect:(XMPPStream *)sender {
    NSLog(@"🔌socket正在鏈接...");
}

- (void)xmppStream:(XMPPStream *)sender socketDidConnect:(GCDAsyncSocket *)socket {
    NSLog(@"🍎socket鏈接成功");
    // 鏈接成功以後，由客戶端xmpp發送一個stream包給服務器，服務器監聽來自客戶端的stream包，並返回stream feature包
}

- (void)xmppStream:(XMPPStream *)sender didNotAuthenticate:(NSXMLElement *)error {
    NSLog(@"😂xmpp受權失敗:%@", error.description);
}

- (void)xmppStreamDidAuthenticate:(XMPPStream *)sender {
    NSLog(@"🍎xmpp受權成功。");
    // 只有進入到這裏，纔算是真正的能夠聊天了
}

- (void)xmppStreamDidDisconnect:(XMPPStream *)sender withError:(NSError *)error {
    NSLog(@"😂xmpp失去鏈接。");
}

@end
複製代碼

####AppDelegate 在AppDelegate中主要設置了下進入APP時的登入狀態，在一些場景中，某些控制器必須爲登入狀態才能進入，用NSUserDefaults存儲爲Bool類型，這爲判斷是否登入提供了方便。app

######AppDelegate.m框架

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    
    //設置主窗口並顯示
    self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
    self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];
    
    //設置進入APP爲沒登入狀態
    [[NSUserDefaults standardUserDefaults] setBool:NO forKey:@"isLoginStatus"];
    [[NSUserDefaults standardUserDefaults] synchronize];
    
    //設置好友列表控制器爲根視圖
    RosterTableViewController *VC = [[RosterTableViewController alloc] init];
    UINavigationController *NC = [[UINavigationController alloc] initWithRootViewController:VC];
    self.window.rootViewController = NC;
    
    return YES;
}
複製代碼

####RosterTableViewController RosterTableViewController主要做用就是進行自動登入與顯示獲取到的好友。dom

######RosterTableViewController.msocket

@interface RosterTableViewController ()

//用於保存獲取到的好友
@property (nonatomic,strong)NSMutableArray *rosterArray;

@end

@implementation RosterTableViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.title = @"好友列表";
    
    self.rosterArray = [[NSMutableArray alloc] init];
    
    //判斷以前是否登入過
    if (nil != [[NSUserDefaults standardUserDefaults]objectForKey:@"userName"]) {
        
        //以前登入過，直接讀取用戶名和密碼進行鏈接
        NSString *userName = [[NSUserDefaults standardUserDefaults]objectForKey:@"userName"];
        NSString *password = [[NSUserDefaults standardUserDefaults]objectForKey:@"password"];
        [[XMPPManager sharedXMPPManager]loginWithUserName:userName password:password];
        [[XMPPManager sharedXMPPManager].stream addDelegate:self delegateQueue:dispatch_get_main_queue()];
        
    }else{
        
        //以前沒登入過則進入到登入窗口
        UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
        LoginViewController *loginVC = [storyboard instantiateViewControllerWithIdentifier:@"login"];
        
        [self.navigationController pushViewController:loginVC animated:YES];
    }
    
    [[XMPPManager sharedXMPPManager].roster addDelegate:self delegateQueue:dispatch_get_main_queue()];
}

#pragma mark UITableViewDataSource
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}

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

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell"];
    if (!cell) {
        cell = [[UITableViewCell alloc] initWithStyle:(UITableViewCellStyleDefault) reuseIdentifier:@"cell"];
    }
    
    XMPPJID *jid = self.rosterArray[indexPath.row];
    cell.textLabel.text = jid.user;
    
    return cell;
}

#pragma mark 進入聊天界面
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
    XMPPJID *jid = self.rosterArray[indexPath.row];
    ChatViewController *chat = [[ChatViewController alloc] init];
    chat.chatToJid = jid;
    [self.navigationController pushViewController:chat animated:YES];
}

#pragma mark XMPPStreamDelegate
//受權成功
- (void)xmppStreamDidAuthenticate:(XMPPStream *)sender{
    [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"isLoginStatus"];
    
    [[NSUserDefaults standardUserDefaults] synchronize];
    
    //咱們驗證以後默認的狀態是離線的 因而咱們想顯示在線，須要告訴服務器本身的狀態
    XMPPPresence *presence = [XMPPPresence presenceWithType:@"available"];
    [[XMPPManager sharedXMPPManager].stream sendElement:presence];
}

//驗證失敗
-(void)xmppStream:(XMPPStream *)sender didNotAuthenticate:(DDXMLElement *)error{
    NSLog(@"登入驗證失敗😂");
}

#pragma mark XMPPRosterDelegate
//剛開始獲取好友列表
-(void)xmppRosterDidBeginPopulating:(XMPPRoster *)sender{
    NSLog(@"開始獲取好友列表");
}

//正在獲取好友列表
-(void)xmppRoster:(XMPPRoster *)sender didReceiveRosterItem:(DDXMLElement *)item{
    NSLog(@"正在獲取好友列表...%@",item);
    NSString *jidStr = [[item attributeForName:@"jid"]stringValue];
    XMPPJID *jid =[XMPPJID jidWithString:jidStr];
    [self.rosterArray addObject:jid];
    
    //將數據添加進數組
    [self.tableView insertRowsAtIndexPaths:@[[NSIndexPath indexPathForRow:self.rosterArray.count-1 inSection:0]] withRowAnimation:UITableViewRowAnimationLeft];
}

//已經完成好友列表獲取
-(void)xmppRosterDidEndPopulating:(XMPPRoster *)sender{
    NSLog(@"已經完成好友列表獲取🍅");
}

複製代碼

####LoginViewController LoginViewController中使用XMPPManager單例在登入按鈕的點擊事件中調用- (void)loginWithUserName:(NSString ***)userName password:(NSString *)password;方法進行登入。工具

######LoginViewController.mfetch

@interface LoginViewController ()

//登入帳戶
@property (weak, nonatomic) IBOutlet UITextField *userName;
//登入密碼
@property (weak, nonatomic) IBOutlet UITextField *password;

@end

@implementation LoginViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    [[XMPPManager sharedXMPPManager].stream addDelegate:self delegateQueue:dispatch_get_main_queue()];
}

//登入操做
- (IBAction)loginAction:(id)sender {
    [[XMPPManager sharedXMPPManager] loginWithUserName:self.userName.text password:self.password.text];
}

#pragma mark XMPPStreamDelegte
//驗證成功
- (void)xmppStreamDidAuthenticate:(XMPPStream *)sender{
    //存儲帳戶密碼用於下次自動登入
    [[NSUserDefaults standardUserDefaults] setObject:self.userName.text forKey:@"userName"];
    [[NSUserDefaults standardUserDefaults] setObject:self.password.text forKey:@"password"];
    
    //改變APP的登入狀態
    [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"isLoginStatus"];
    [[NSUserDefaults standardUserDefaults] synchronize];
    
    //驗證以後默認的狀態爲離線，須要手動告訴服務器本身的狀態
    XMPPPresence *presence = [XMPPPresence presenceWithType:@"available"];
    [[XMPPManager sharedXMPPManager].stream sendElement:presence];
    
    //返回到根視圖
    [self.navigationController popToRootViewControllerAnimated:YES];
}

//驗證失敗
-(void)xmppStream:(XMPPStream *)sender didNotAuthenticate:(DDXMLElement *)error{
    NSLog(@"登入驗證失敗😂");
}
複製代碼

####RegisterViewController 註冊和登入比較類似，只需在註冊按鈕的點擊事件中使用XMPPManager單例調用- (void)registWithUserName:(NSString *)userName password:(NSString *)password;方法進行註冊。

######RegisterViewController.m

@interface RegisterViewController ()

//註冊帳戶
@property (weak, nonatomic) IBOutlet UITextField *userName;
//註冊密碼
@property (weak, nonatomic) IBOutlet UITextField *password;
//密碼驗證
@property (weak, nonatomic) IBOutlet UITextField *rePassword;

@end

@implementation RegisterViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    [[XMPPManager sharedXMPPManager].stream addDelegate:self delegateQueue:dispatch_get_main_queue()];
}

- (IBAction)registerAction:(id)sender {
    //簡單驗證：用戶名不爲空且密碼和密碼驗證輸入一致
    if (![self.userName.text isEqualToString:@""] && [self.rePassword.text isEqualToString:self.password.text]) {
        [[XMPPManager sharedXMPPManager] registWithUserName:self.userName.text password:self.password.text];
    }else{
        UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"註冊失敗" message:@"" preferredStyle:(UIAlertControllerStyleAlert)];
        
        if ([self.userName.text isEqualToString:@""]) {
            alertController.title = @"帳戶爲空";
            alertController.message = @"請輸入帳戶";
        }
        if (![self.rePassword.text isEqualToString:self.password.text]) {
            alertController.title = @"密碼驗證錯誤";
            alertController.message = @"請從新輸入密碼驗證";
        }
        
        UIAlertAction *okAction = [UIAlertAction actionWithTitle:@"OK" style:(UIAlertActionStyleCancel) handler:^(UIAlertAction * _Nonnull action) {
            [alertController dismissViewControllerAnimated:YES completion:nil];
        }];
        
        [alertController addAction:okAction];
        [self presentViewController:alertController animated:YES completion:nil];
    }
}

#pragma mark--XMPPStreamDelegate
//註冊成功
-(void)xmppStreamDidRegister:(XMPPStream *)sender{
    NSLog(@"%s__%d__註冊成功",__FUNCTION__,__LINE__);
    
    //存儲帳戶密碼用於下次自動登入
    [[NSUserDefaults standardUserDefaults] setObject:self.userName.text forKey:@"userName"];
    [[NSUserDefaults standardUserDefaults] setObject:self.password.text forKey:@"password"];
    
    //改變APP的登入狀態
    [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"isLoginStatus"];
    [[NSUserDefaults standardUserDefaults] synchronize];
    
    //驗證以後默認的狀態爲離線，須要手動告訴服務器本身的狀態
    XMPPPresence *presence = [XMPPPresence presenceWithType:@"available"];
    [[XMPPManager sharedXMPPManager].stream sendElement:presence];
    
    //註冊成功以後返回到登錄界面
    [self.navigationController popToRootViewControllerAnimated:YES];
}
//註冊失敗
-(void)xmppStream:(XMPPStream *)sender didNotRegister:(DDXMLElement *)error{
    NSLog(@"%s__%d__註冊失敗%@",__FUNCTION__,__LINE__,error);
}

複製代碼

####ChatViewController 在ChatViewController中須要公開一個屬性，用來接收好友列表頁面傳來的XMPPJID。 ######ChatViewController.h

@interface ChatViewController : UIViewController

@property (nonatomic,strong)XMPPJID *chatToJid;

@end
複製代碼

######ChatViewController.m

@interface ChatViewController ()<UITableViewDataSource,UITableViewDelegate>

//顯示消息
@property (weak, nonatomic) IBOutlet UITableView *messageContent;
//消息輸入框
@property (weak, nonatomic) IBOutlet UITextView *messageTextView;
//鍵盤底部約束
@property (weak, nonatomic) IBOutlet NSLayoutConstraint *messageTextfieldConstraint;
//存儲消息數據
@property (nonatomic,strong) NSMutableArray *allMessageArray;

@end

@implementation ChatViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.messageTextView.text = @"";

    self.messageContent.delegate = self;
    self.messageContent.dataSource = self;
    
    self.allMessageArray = [[NSMutableArray alloc] init];
    //將歷史消息加入到數組
    [self.allMessageArray addObjectsFromArray:[self fromDataBaseFetchResult]];
    
    //監聽鍵盤frame的改變
    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(kbFrameWillChange:) name:UIKeyboardWillChangeFrameNotification object:nil];
    
    [[XMPPManager sharedXMPPManager].stream addDelegate:self delegateQueue:dispatch_get_main_queue()];
    
    [self reloadMessage];
    
    self.messageContent.separatorStyle = UITableViewCellSeparatorStyleNone;
}

//消息發送按鈕
- (IBAction)sendMessageAction:(id)sender {
    XMPPMessage *message = [XMPPMessage messageWithType:@"chat" to:self.chatToJid];
    //要發送的消息添加到Body
    [message addBody:self.messageTextView.text];
    //發送消息
    [[XMPPManager sharedXMPPManager].stream sendElement:message];
}

//鍵盤即將改變frame
- (void)kbFrameWillChange:(NSNotification *)noti{
    //獲取窗口的高度
    CGFloat windowH = [UIScreen mainScreen].bounds.size.height;
    //鍵盤結束的frm
    CGRect kbEndFrm = [noti.userInfo [UIKeyboardFrameEndUserInfoKey]CGRectValue];
    //鍵盤結束的y值
    CGFloat kbEndY = kbEndFrm.origin.y;
    self.messageTextfieldConstraint.constant = windowH - kbEndY;
    
    [self scrollsToBottomAnimated:YES];
}

- (void)scrollsToBottomAnimated:(BOOL)animated{
    CGFloat offset = self.messageContent.contentSize.height - self.messageTextfieldConstraint.constant - 55;
    if (offset > 0){
        [self.messageContent setContentOffset:CGPointMake(0, offset) animated:animated];
    }
}

#pragma mark XMPPStreamDelegate
//發送信息成功
-(void)xmppStream:(XMPPStream *)sender didSendMessage:(XMPPMessage *)message{
    NSLog(@"發送成功🍅");
    [self reloadMessage];//發送信息時刷新一次頁面
}

//發送信息失敗
-(void)xmppStream:(XMPPStream *)sender didFailToSendMessage:(XMPPMessage *)message error:(NSError *)error{
    NSLog(@"發送失敗⚠️");
}

//收到信息
-(void)xmppStream:(XMPPStream *)sender didReceiveMessage:(XMPPMessage *)message{
    NSLog(@"收到消息%@",message);
    if ([message isChatMessageWithBody]) {
        [self reloadMessage];//收到信息是刷新一次頁面
    }
}

#pragma mark 加載聊天信息
-(void)reloadMessage{
    
    //從數據庫讀取數據
    NSArray *fetchedObjects = [self fromDataBaseFetchResult];
    
    // 清空消息數組裏的全部數據
    [self.allMessageArray removeAllObjects];
    // 將新的聊天記錄添加到數組中
    [self.allMessageArray addObjectsFromArray:fetchedObjects];
    
    //將信息加載到tableView上
    [self.messageContent reloadData];
    
    //加載時滾動到最底部
    [self scrollToBottomWithAnimated:YES];
}

//從數據庫讀取數據
- (NSArray *)fromDataBaseFetchResult{
    //1.上下文
    NSManagedObjectContext *managerObjectContext =[XMPPManager sharedXMPPManager].managerObjectContext;
    
    //2.建立查詢請求
    NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"XMPPMessageArchiving_Message_CoreDataObject"];
    
    //3.設置過濾條件(提取當前用戶jid,好友jid)
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"bareJidStr == %@ And streamBareJidStr == %@", self.chatToJid.bare,[XMPPManager sharedXMPPManager].stream.myJID.bare];
    fetchRequest.predicate = predicate;
    
    //4.設置排序(時間升序)
    NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"timestamp" ascending:YES];
    fetchRequest.sortDescriptors = @[sortDescriptor];
    
    //5.執行請求
    NSError *error = nil;
    NSArray *fetchedResult = [managerObjectContext executeFetchRequest:fetchRequest error:&error];
    
    return fetchedResult;
}

//滾動到最底部
- (void)scrollToBottomWithAnimated:(BOOL)animated{
    
    if (animated && [self.messageContent numberOfSections] > 0) {
        
        NSInteger lastSectionIndex = [self.messageContent numberOfSections] - 1;
        NSInteger lastRowIndex = [self.messageContent numberOfRowsInSection:lastSectionIndex] - 1;
        
        if (lastRowIndex > 0) {
            
            NSIndexPath *lastIndexPath = [NSIndexPath indexPathForRow:lastRowIndex inSection:lastSectionIndex];
            [self.messageContent scrollToRowAtIndexPath:lastIndexPath atScrollPosition: UITableViewScrollPositionBottom animated:animated];
        }
    }
}

#pragma mark UITableViewDataSourceDelegate
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
    return self.allMessageArray.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
    
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell"];
    if (nil == cell) {
        cell = [[UITableViewCell alloc] initWithStyle:(UITableViewCellStyleValue1) reuseIdentifier:@"cell"];
    }
    
    XMPPMessageArchiving_Message_CoreDataObject *chatMessage = self.allMessageArray[indexPath.row];
    
    //判斷聊天信息是發出去的 仍是接受進來的，在cell上顯示不同的樣式
    if (chatMessage.isOutgoing == YES) {
        cell.detailTextLabel.text = chatMessage.body;
        cell.textLabel.text = @"";
    } else {
        cell.textLabel.text = chatMessage.body;
        cell.detailTextLabel.text = @"";
    }
    
    self.messageTextView.text = @"";
    
    return cell;
}
複製代碼