[SOLVED] Memory access error with QSqlTableModel subclass
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Solution: The problem was apparently a dependency issue caused by incorrect build. Re-building everything solved the issue. It seems that making full rebuild once in a while might be a good habit.
Hi,
I have a QSqlTableModel subclass that has two QList and one QString as private members. This is custom part of the model:@class OCMSqlTableModel : public QSqlTableModel
{
Q_OBJECT
public:
explicit OCMSqlTableModel(QObject *parent = 0) : QSqlTableModel(QObject) { }void setMIMEType(const QString &table); void setDropSourceMap(const QList<int> &map) void disableEditingForColumn(int column);
private:
QString m_sMIMEType;
QList<int> m_DropSourceTargetMap;
QList<int> m_DisabledColumns;public:
virtual Qt::ItemFlags flags(const QModelIndex &index) const override;
//rest of reimplemented stuff
};void OCMSqlTableModel::disableEditingForColumn(int column);
{
m_DropSourceTargetMap.append(column);
}Qt::ItemFlags OCMSqlTableModel::flags(const QModelIndex &index) const
{
Qt::ItemFlags flags = QSqlTableModel::flags(index) | Qt::ItemIsDropEnabled;if(index.isValid()) { if(m_DisabledColumns.contains(index.column())) flags ^= Qt::ItemIsEditable; return flags | Qt::ItemIsDragEnabled; } return flags;
}@
The problem is that like this it crashes in the flags() in the nested if checking whether the column is disabled (contained in the QList<int> private member).
In debugging I found something super-odd. When this function is called, only the first QList is actually initialized while the second is inaccessible. When I swap them, everything works fine but the other QList is now inaccessible.
What the heck is going on? Can someone please explain it? Or is it a bug?
Thx.
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Hi,
Probably not related but
@
explicit OCMSqlTableModel(QObject *parent = 0) : QSqlTableModel(QObject) { }
@Should rather be
@
explicit OCMSqlTableModel(QObject *parent = 0) : QSqlTableModel(parent) { }
@Or was it a typo ?
Anyway, what combo of Qt/OS/compiler are you using ?
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Yeah, it was a typo. :-)
I am using Qt 5.3.2 with Ming 4.8.2 on Windows 8 64-bit.
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Looks like a dependency/linking problem, make sure to recompile the entire project.
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Ha, indeed you were right mmoll! How odd. Recompiling the whole thing fixed the issue and all members are properly initialized now.