QMap

[sophister]

Hi, I want to modify the value in a QMap, but when I tried to modify it through QMap::value(), I failed, because this method always return a value which is const(cannot be changed).
Do you guys know how to change the value in QMap??
Thanks!

[munna]

You can modify the value using [] operator. Some like this

map["one"] = 1;
map["three"] = 3;
map["seven"] = 7;

map["one"] = 1;
map["three"] = 3;
map["seven"] = 7;

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[sophister]

Thanks, but if I am using QMap in this way, QMap<int, QMap<QString, QToolButton *> >, then how can I add QToolButton into the inner QMap??

[munna]

Like this

map[1]["one"] = toolButton

map[1]["one"] = toolButton

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[sophister]

I use this, but the application crashed:

QMap<QString, QToolButton *> *currentButtons = const_cast<QMap<QString, QToolButton *>*>(tabs.value(ui->tabWidget->currentIndex()));
currentButtons->insert(path, btn);        //This line is where the error lie

QMap<QString, QToolButton *> *currentButtons = const_cast<QMap<QString, QToolButton *>*>(tabs.value(ui->tabWidget->currentIndex()));
currentButtons->insert(path, btn);        //This line is where the error lie

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I am really puzzled.
Did I fail to const_cast the const into non-cosnt so that I cannot insert a value into a const variable??

[lyuts]

There is an iterator for map.