Qt中QTableView中加入Check列实现

      通过Delegate创建QCheckBox来实现的Check列，只有在该列进入编辑模式时才能够Check/Uncheck。这显然不是我们想要的，网上翻来翻去，在一个国外论坛中看到了无需Delegate的实现方法，只需重写Model即可：

class MyModel : public QSqlQueryModel {
    Q_OBJECT
public:
    MyModel(QObject *parent = 0);
    Qt::ItemFlags flags(const QModelIndex &index) const;
    QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const;
........
};

Qt::ItemFlags MyModel::flags(const QModelIndex &index) const {
    Qt::ItemFlags flags = QSqlQueryModel::flags(index);
    if (index.column() == aColWithCheckbox)
        flags |= Qt::ItemIsUserCheckable;
    else
        flags |= Qt::ItemIsEditable;
    return flags;
}

QVariant MyModel::data(const QModelIndex &index,  int role) const {
  QVariant value = QSqlQueryModel::data(index, role);
  if (role == Qt::CheckStateRole && index.column() == aColWithCheckbox)
    return (QSqlQueryModel::data(index).toInt() != 0) ? Qt::Checked : Qt::Unchecked;
  else
    return value;
}