快速重新加载表视图后，表视图未更新

Question

I am using socket.io for instant chatting.

I went message list screen from User List ,first time its working fine.

Message has been sent and receive properly first time but i came back again on message list, Some glitch are occurring and on sending and receiving any message tableview is not updating while table view is reloading.

on sending or receiving message given module are calling

In ViewDidAppear

    **// on sending or receiving message given module are calling**

    SocketIOManager.sharedInstance.getChatMessage { (messageInfo) -> Void in

        //----------- Get value from Resulted array --------------
        self.txtField_Chat.text = ""
        self.isSendBtnEnabled(val: false)

        let result_arr = messageInfo["data"] as! NSArray
        let result_dic = result_arr[0] as? NSDictionary

        let result_string_date : String = result_dic!.value(forKey: "date") as! String
        let result_array : NSArray = result_dic!.value(forKey: "value") as! NSArray
        let result_dic_value : NSDictionary = result_array[0] as! NSDictionary
        // ----------------------------------------------
        // ----------- Get value from current array --------------
        if self.arr_message_All.count > 0{
            let recentdate_dic : NSDictionary = self.arr_message_All[self.arr_message_All.count - 1] as NSDictionary
            let recentdate : String = recentdate_dic.value(forKey: "date") as! String
            let recentdate_array : NSArray = recentdate_dic.value(forKey: "value") as! NSArray
            let recentdate_arrayM : NSMutableArray = recentdate_array.mutableCopy() as! NSMutableArray
            let dic_message = Message(dictionary: result_dic_value.value(forKey: "message") as! NSDictionary)
            // ----------------------------------------------
            var get_msg_id : String = ""
            if let msg_id = defaults.value(forKey: "m_id") as? String{
                get_msg_id = msg_id
            }
            if !(dic_message?.msg_m_id == get_msg_id){

                if (messageInfo["status"] as! NSString) == "Success"{
                    print("********************",dic_message!.msg_value)
                    //
                    if recentdate == result_string_date{
                        //                                DispatchQueue.main.async {
                        print("Before insertion row count ",recentdate_arrayM.count)
                        recentdate_arrayM.add(result_dic_value)
                        print("Afer insertion row count ",recentdate_arrayM.count)
                        var dic = NSDictionary()
                        dic = ["date":recentdate , "value" : recentdate_arrayM]
                        self.arr_message_All[(self.arr_message_All.count) - 1] = dic
                        // First figure out how many sections there are
                        let lastSectionIndex = self.tblView_chat.numberOfSections - 1
                        // Then grab the number of rows in the last section
                        let lastRowIndex = self.tblView_chat!.numberOfRows(inSection: lastSectionIndex)
                        // Now just construct the index path
                        let pathToLastRow = NSIndexPath(row: lastRowIndex, section: lastSectionIndex)
                        print("in Socket",lastSectionIndex,lastRowIndex)
                        self.tblView_chat.reloadData()
                        self.tblView_chat.beginUpdates()
                        //                                    self.tblView_chat.insertRows(at: [(pathToLastRow as IndexPath)], with: .automatic)
                        self.tblView_chat.endUpdates()
                        self.tblView_chat?.scrollToRow(at: pathToLastRow as IndexPath as IndexPath, at: UITableView.ScrollPosition.none, animated: true)
                    }
                    else{
                        self.arr_message_All.append(result_dic!)
                        self.tblView_chat.reloadData()
                        self.scrollToBottomOfChat()
                        //                            })
                    }
                }
                //end Of If Condition
            }
            defaults.set(dic_message?.msg_m_id, forKey: "m_id") //setObject
        }
    }

Answer 1

You have to call reloadData , beginUpdates and all other UI-related tasks in main queue only .

wrap all your UI-related lines in this:

 DispatchQueue.main.async { // all UI-related stuff self.tblView_chat.reloadData() self.tblView_chat.beginUpdates() self.tblView_chat.insertRows(at: [(pathToLastRow as IndexPath)], with: .automatic) self.tblView_chat.endUpdates() self.tblView_chat?.scrollToRow(at: pathToLastRow as IndexPath as IndexPath, at: UITableView.ScrollPosition.none, animated: true) }