c++ - QItemSelectionModel::selectedIndexes() 崩溃

Question

我一直在四处寻找这个问题的解决方案，我开始相信这可能是 Qt 函数本身的一个错误。问题是，在您调用 QItemSelectionModel::selectedIndexes() 之后，当程序试图破坏此函数返回的 QModelIndexList 时，程序将崩溃。在崩溃之前，您会收到以下调试消息:

Debug Assertion Failed!
(…)
File: f:\dd\vctools\crt_bld\self_x86\crt\src\dbgheap.c
Line:1419
Expression: _pFirstBlock == pHead
(…)

下面是最简单的会导致问题的代码，大家可以自行测试:

#include <QApplication>
#include <QStringList>
#include <QStringListModel>
#include <QItemSelectionModel>
#include <QModelIndex>
#include <QModelIndexList>
#include <QListView>
#include <QItemSelectionModel>

void doSomethingWithSelection(QItemSelectionModel* selectionmodel);

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QStringList list;
    list.push_back("1");
    list.push_back("2");
    list.push_back("3");
    list.push_back("4");
    QStringListModel model(list);
    QListView view;
    view.setModel(&model);
    view.setSelectionMode(QAbstractItemView::ExtendedSelection);

    QItemSelectionModel *selectionmodel = view.selectionModel();
    QModelIndex first = model.index(0);
    QModelIndex last = model.index(2);
    QItemSelection selection(first, last);
    selectionmodel->select(selection,QItemSelectionModel::Select);

    doSomethingWithSelection(selectionmodel);

    view.show();
    return a.exec();
}

void doSomethingWithSelection(QItemSelectionModel* selectionmodel)
{
    QModelIndexList indexlist = selectionmodel->selectedIndexes();
    // this is what causes the error. I put this inside a function
    // so the error will happen when exiting the function,
    // when the program try to destroy the list nodes.
}

Answer 1

我有完全相同的问题，只是我使用的是选定的行而不是选定的索引。当 QModelIndexList 中的内部 QList 尝试从堆中删除索引时，我将其缩小为函数退出。不确定如何修复它，但我阅读了这篇有趣的帖子 here并想出了这个功能:

QModelIndexList Class::getViewSelection(QAbstractItemView *view ,  int columnNumber) const
{
  QModelIndexList list;
  for (int row = 0; row < view->model()->rowCount(view->rootIndex()); ++row)
  {
    QModelIndex index = view->model()->index(row, columnNumber, view->rootIndex());

    if (view->selectionModel()->isSelected(index))
        list.push_back(index);
   }
  return list;
}

我编写此函数是为了获取选定的行，因此列参数是您想要索引的列。