XMPP系列(四）---傳送和接收文字訊息，獲取歷史訊息功能

今天開始做到最主要的功能傳送和接收訊息、獲取本地歷史資料。

先上到目前為止的效果圖：

首先是要在XMPPFramework.h中引入資料儲存模組：

//聊天記錄模組的匯入

#import "XMPPMessageArchiving.h"

#import "XMPPMessageArchivingCoreDataStorage.h"

#import "XMPPMessageArchiving_Contact_CoreDataObject.h" //最近聯絡人

#import "XMPPMessageArchiving_Message_CoreDataObject.h"

然後在XMPPStream中新增資料儲存模組，因為XMPP框架預設用CoreData儲存資料，而且做好了資料儲存，因此我們只需要在合適的地方傳送通知處理資訊即可。

 //4.訊息模組，這裡用單例，不能切換賬號登入，否則會出現資料問題。

        _xmppMessageArchivingCoreDataStorage = [XMPPMessageArchivingCoreDataStorage sharedInstance];

        _xmppMessageArchiving = [[XMPPMessageArchiving alloc] initWithMessageArchivingStorage:_xmppMessageArchivingCoreDataStorage dispatchQueue:dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 9)];

        [_xmppMessageArchiving activate:self.xmppStream];

在資料儲存完畢後，傳送通知：

在XMPPMessageArchivingCoreDataStorage的

- (void)archiveMessage:(XMPPMessage *)message outgoing:(BOOL)isOutgoing xmppStream:(XMPPStream
*)xmppStream結尾處新增如下通知：

    dispatch_async(dispatch_get_main_queue(), ^{

        [[NSNotificationCenter defaultCenter] postNotificationName:kXMPP_MESSAGE_CHANGE object:nil];

    });

現在去聊天介面獲取歷史訊息吧：

/** 查詢聊天記錄 */

- (void)getChatHistory

{

    XMPPMessageArchivingCoreDataStorage *storage = [JKXMPPTool sharedInstance].xmppMessageArchivingCoreDataStorage;

    //查詢的時候要給上下文

    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];

    NSEntityDescription *entity = [NSEntityDescription entityForName:storage.messageEntityName inManagedObjectContext:storage.mainThreadManagedObjectContext];

    [fetchRequest setEntity:entity];

    // Specify criteria for filtering which objects to fetch

    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"bareJidStr = %@", self.chatJID.bare];

    [fetchRequest setPredicate:predicate];

    // Specify how the fetched objects should be sorted

    NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"timestamp"

                                                                   ascending:YES];

    [fetchRequest setSortDescriptors:[NSArray arrayWithObjects:sortDescriptor, nil]];

    NSError *error = nil;

    NSArray *fetchedObjects = [storage.mainThreadManagedObjectContext executeFetchRequest:fetchRequest error:&error];

    if (fetchedObjects != nil) {

        self.chatHistory = [[NSMutableArray alloc] initWithArray:fetchedObjects];

        //        [NSMutableArray arrayWithArray:fetchedObjects];

    }

    [self.messageTableView reloadData];

    [self tableViewScrollToBottom];

}

訊息接收也呼叫getChatHistory方法即可

而訊息的傳送是：

/** 傳送的事件 */

- (void)sendMessage{

    if (_chatTextField.text.length < 1) {

        return;

    }

    XMPPMessage *message = [XMPPMessage messageWithType:@"chat" to:self.chatJID];

    [message addBody:_chatTextField.text];

    [[JKXMPPTool sharedInstance].xmppStream sendElement:message];

    _chatTextField.text = @"";

    [self tableViewScrollToBottom];

}

demo地址：https://github.com/Joker-King/ChatDemo