void Widget::readyRead_slot()
{
    //读取服务器发来的数据
    QByteArray msg = socket->readAll();
    QString str = QString::fromLocal8Bit(msg);
    QStringList list = str.split(':');
    if(list.at(0)== userName)
    {
        
        QString str2;

        for (int i = 1; i < list.count(); ++i) {
            str2 += list.at(i); //拼接字符串
        }

        str2 += ":";
        str2 += list.at(0);

        // 直接在添加新项时设置对齐方式
        QListWidgetItem* item = new QListWidgetItem(str2, ui->listWidget);
        item->setTextAlignment(Qt::AlignRight);
    }
    //将数据放入ui界面
    else
    {
        ui->listWidget->addItem(QString::fromLocal8Bit(msg));
    }
}