Question

I have q method that shown at below:

   void MainWindow::slotResults( const QList<QSqlRecord>& records )
    {
        ui->lineEditWord->setCompleter(0);
        QStringList wordList;
        for(int i = 0; i < records.count(); i++)
        {
            wordList.append( QString("%1").arg( records.value(i).value(0).toString()));
        }
        QCompleter *completer = new QCompleter(wordList, this);
       // completer->setCaseSensitivity(Qt::CaseInsensitive);
        ui->lineEditWord->setCompleter(completer);



    }

But, when line ui->lineEditWord->setCompleter(completer) have beeen execited; memory usage increase and when i call this method for several times, memory usage grow up. so how can i release memory from this? Should i remove current completer of lineEdit

pls help

Answer 1

The QCompleter constructor you are using takes a QStringList as parameter. It is certainly (while this is not documented properly), a convenience constructor that creates a QStringListModel filled with the strings passed to the constructor and set this model as the completion model with QCompleter::setModel().

You can update the string list represented by the model using the following code:

QStringList originalStringList;
originalStringList << "red" <<"orange" << "yellow";
QCompleter *completer = new QCompleter(originalStringList);

QStringListModel *stringListModel = qobject_cast< QStringListModel* >(completer->model());

QStringList newStringList;
newStringList << "blue" <<"green" << "purple";
stringListModel->setStringList(wewStringList);

If you want to be sure of what you are doing, I suggest to create the completer and data model separately:

QCompleter *completer = new QCompleter();
QStringListModel *stringListModel = new QStringListModel();
completer->setModel(stringListModel);

QStringList originalStringList;
originalStringList << "red" <<"orange" << "yellow";
stringListModel->setStringList(originalStringList);

In this case, you just have to store the stringListModel as a member of your MainWindow and update the string list each time you pass through the MainWindow::slotResults() method.