/// <summary>
        ///     发送消息
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void sendMsg_Click(object sender, RoutedEventArgs e)
        {
            onlineFriendType sendTo = (onlineFriendType)onlineFriendlistListBox.SelectedItem;

            byte[] arrMsg, sendArrMsg;

            Paragraph newParagraph = new Paragraph();

            Run run = new Run()
            {
                Text = "我  " + System.DateTime.Now.ToString() + "\r\n",
                Foreground = new SolidColorBrush(Colors.Blue)
            };
            newParagraph.Inlines.Add(run);

            InlineUIContainer inlineUIContainer = new InlineUIContainer()
            {

                Child = new TextBlock()
                {
                    Foreground = new SolidColorBrush(Colors.Black),
                    TextWrapping = TextWrapping.Wrap,
                    Text = "  " + inputTextBox.Text + "\r\n"
                }
            };

            newParagraph.Inlines.Add(inlineUIContainer);

            if (sendTo.nameAndId.Equals("所有人"))
            {
                MsgHandler msgHandler = new MsgHandler(userData.userId, userData.userName, "", inputTextBox.Text);

                string sendMsg = JsonConvert.SerializeObject(msgHandler);
                arrMsg = Encoding.UTF8.GetBytes(sendMsg);
                sendArrMsg = new byte[arrMsg.Length + 1];

                // 设置标志位,代表更新用户信息
                sendArrMsg[0] = MSG_TO_ALL;
                Buffer.BlockCopy(arrMsg, 0, sendArrMsg, 1, arrMsg.Length);

                dictParagraph["AllUsers"].Add(newParagraph);
                chatRichTextBox.Document.Blocks.Add(newParagraph);
            }
            else
            {
                MsgHandler msgHandler = new MsgHandler(userData.userId, userData.userName, sendTo.userData.userId, inputTextBox.Text);

                string sendMsg = JsonConvert.SerializeObject(msgHandler);

                arrMsg = Encoding.UTF8.GetBytes(sendMsg);
                sendArrMsg = new byte[arrMsg.Length + 1];

                // 设置标志位,代表更新用户信息
                sendArrMsg[0] = MSG_TO_INDIVIDULAL;
                Buffer.BlockCopy(arrMsg, 0, sendArrMsg, 1, arrMsg.Length);

                dictParagraph[sendTo.userData.userId].Add(newParagraph);
                chatRichTextBox.Document.Blocks.Add(newParagraph);
            }

            try
            {
                socketClient.Send(sendArrMsg);
                inputTextBox.Text = "";
            }
            catch (SocketException se)
            {
                Console.WriteLine("【错误】发送消息异常:" + se.Message);
                return;
            }
            catch (Exception ex)
            {
                Console.WriteLine("【错误】发送消息异常:" + ex.Message);
                return;
            }
        }
        /// <summary>
        ///     接收到群发给所有人的消息
        /// </summary>
        /// <param name="msgHandler"></param>
        private void ReceiveMsgForIndividual(MsgHandler msgHandler)
        {
            List<Paragraph> userParagraphList = dictParagraph[msgHandler.from];

            Paragraph newParagraph = new Paragraph();

            Run run = new Run()
            {
                Text = msgHandler.fromName + "  " + System.DateTime.Now.ToString() + "\r\n",
                Foreground = new SolidColorBrush(Colors.Red)
            };
            newParagraph.Inlines.Add(run);

            InlineUIContainer inlineUIContainer = new InlineUIContainer()
            {

                Child = new TextBlock()
                {
                    Foreground = new SolidColorBrush(Colors.Black),
                    TextWrapping = TextWrapping.Wrap,
                    Text = "  " + msgHandler.message + "\r\n"
                }
            };

            newParagraph.Inlines.Add(inlineUIContainer);

            userParagraphList.Add(newParagraph);

            onlineFriendType sendTo = (onlineFriendType)onlineFriendlistListBox.SelectedItem;

            if (sendTo.nameAndId.Equals("所有人") == false && sendTo.userData.userId.Equals(msgHandler.from))
                chatRichTextBox.Document.Blocks.Add(newParagraph);
            else
            {
                int index;
                if (FindItemByUserId(msgHandler.from, out index))
                {
                    onlineFriendType user = (onlineFriendType)onlineFriendlistListBox.Items[index];
                    user.increaseNum();
                    IntPtr activeForm = GetActiveWindow(); // 先得到当前的活动窗体
                    Prompt test = new Prompt("来自 " + msgHandler.fromName + "(" + msgHandler.from + ") 的新消息", 0);
                    cnt = (cnt + 1) % 6;
                    test.Show();
                    SetActiveWindow(activeForm); // 在把焦点还给之前的活动窗体
                }
            }
        }