QSettings how to remove elements from array?

hezf

I have a array save in QSettings
I can modify the element
But I don't know how to remove it
Anybody know?

Ratzz

Hi ,
Did you try remove ? http://doc.qt.io/qt-4.8/qsettings.html#remove

hezf

@Ratzz Yes,I could remove the element's key
But the array's element is still ,just an empty one

Ratzz

I did you get you clearly.. can you show the code or explain me more?

hezf

@Ratzz okay

//this is I write a array
    QSettings setting("TEST","demo1");
    setting.beginWriteArray("array1");
    for(auto i=0;i<10;i++){
        setting.setArrayIndex(i);
        setting.setValue("demo","value"+QString::number(i));
    }
    setting.endArray();

//this is I read a array
    auto size = setting.beginReadArray("array1");
    for(auto i=0;i<size;i++){
        setting.setArrayIndex(i);
        qDebug()<<setting.value("demo");
    }
    setting.endArray();

//read the array and remove
    setting.beginReadArray("array1");
    setting.setArrayIndex(5);
    setting.remove("demo");
    setting.endArray();
//the result is 
//QVariant(QString, "value0")
//QVariant(QString, "value1")
//QVariant(QString, "value2")
//QVariant(QString, "value3")
//QVariant(QString, "value4")
//QVariant(Invalid)
//QVariant(QString, "value6")
//QVariant(QString, "value7")
//QVariant(QString, "value8")
//QVariant(QString, "value9")

//write the array and remove
    setting.beginWriteArray("array1");
    setting.setArrayIndex(5);
    setting.remove("demo");
    setting.endArray();

//result
QVariant(QString, "value0")
QVariant(QString, "value1")
QVariant(QString, "value2")
QVariant(QString, "value3")
QVariant(QString, "value4")
QVariant(Invalid)

Is it clearly?

Ratzz

I think you need to set back the value to QSettings after you remove.

hezf

@Ratzz
But when I want remove the last one ,what can I do?

I get a stupid method,read all keys and value to a list
and then clear the settings
removeat(index) the list
At last ,write this list to settings.