How to show all keys inside QMap with QStringList?

Question

I have a problem with QMap. Each key has many values. The idea is to show all values with its unique key. To iterate through this map with a QtGui application, I have the TextEdit (name: t2). The code is inside a button goes as:

void MainWindow::on_push2_clicked()
{
    QMap<int, QStringList> myMaps;
    myMaps[1].append("Autodesk Maya 2014");
    myMaps[1].append("Autodesk Inventor 2014");
    myMaps[1].append("Autodesk Alias 2014");
    myMaps[1].append("Autodesk 3ds Max 2014");
    myMaps[1].append("Autodesk Softimage 2014");
    myMaps[2].append("Adobe Photoshop CS6");
    myMaps[2].append("Adobe Illustrator CS6");
    myMaps[2].append("Adobe InDesign CS6");
    myMaps[1].append("Autodesk AutoCAD 2014");

    QStringList stsl; // the StringList which contains all values

    QMap<int, QStringList>::iterator it;

    for (it=myMaps.begin(); it!=myMaps.end(); ++it) {
    QString qsi=QString::number(it.key());
    QString qs=it.value().join(" - ");        
    stsl << "<span style='color:#FF1000;font-weight:bold;'>"+qsi + " : </span>"+ qs;
    }

      QString st4=stsl.join("<br/>"); //With setHtml
      ui->t2->setHtml(st4);
    }
}

// The output : 1 : Autodesk Maya 2014 - Autodesk Inventor 2014 - Autodesk Alias 2014 - Autodesk 3ds Max 2014 - Autodesk Softimage 2014 - Autodesk AutoCAD 2014 - Lightwave 12 2 : Adobe Photoshop CS6 - Adobe Illustrator CS6 - Adobe InDesign CS6.

// The output which I want to do: 1 : Autodesk Maya 2014 1 : Autodesk Inventor 2014 1 : Autodesk Alias 2014 1 : Autodesk 3ds Max 2014 1 : Autodesk Softimage 2014 1 : Autodesk AutoCAD 2014 2 : Adobe Photoshop CS6 2 : Adobe Illustrator CS6 2 : Adobe InDesign CS6

Answer 1

I would rewrite it in the following way:

[..]
QMultiMap<int, QString> myMaps;

myMaps.insert(1, "Autodesk Maya 2014");
myMaps.insert(1, "Autodesk Inventor 2014");
myMaps.insert(1, "Autodesk Alias 2014");
myMaps.insert(1, "Autodesk 3ds Max 2014");
myMaps.insert(1, "Autodesk Softimage 2014");
myMaps.insert(2, "Adobe Photoshop CS6");
myMaps.insert(2, "Adobe Illustrator CS6");
myMaps.insert(2, "Adobe InDesign CS6");
myMaps.insert(1, "Autodesk AutoCAD 2014");

QMap<int, QString>::iterator it;
QString output;

for (it = myMaps.begin(); it != myMaps.end(); ++it) {
    // Format output here.
    output += QString("%1 : %2").arg(it.key()).arg(it.value());
}
[..]

Answer 2

I have a problem with Qmap, each key has many values.

You are wrong. You are using QMap. So each key has exactly one value. Your one value is a QStringList. With String qs=it.value().join(" - "); you join all strings in this QStringList into one QString.

Ok, I stand corrected. QMap can have more than one value under one and the same key. I totally overlooked 'insertMulti'. Nevertheless, the above statement is in so far still true, as the 'append' methods in his code belong to the QStringList values in the QMap. They do not add an additional value to a key, but add a new QString to the QStringList.