[Qt] difference between QItemSelectionModel::selectedIndexes () and QItemSelectionModel::selectedRows ( int column = 0 )

 

摘自Qt 4.7 docs

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QModelIndexList QItemSelectionModel::selectedIndexes () const

Returns a list of all selected model item indexes. The list contains no duplicates, and is not sorted.

QModelIndexList QItemSelectionModel::selectedRows ( int column = 0 ) const

Returns the indexes in the given column for the rows where all columns are selected.

This function was introduced in Qt 4.2.

See also selectedIndexes() and selectedColumns().

 

 

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PS: 下面的是根据我自己的经验写出的, 请谨慎对待其参考性.

 

 

下面有段代码，用QItemSelectionModel::selectedIndexes ()时indexlist.size()的大小是总item的indexes个数，因为在构造函数当中把表的选择行为设置了SelectionRows (cardView->setSelectionBehavior(QAbstractItemView::SelectRows);), 而每行又有5列，所以每选择一行时indexlist : QItemIndexList总是多出4个重复的index出来， 即当选择一行时，本来indexlist.size()应该是等于1的 (因为只选了一行)，但由于selectedIndexes()是针对表中的单元格, 而不是单元格上对应的行, 所以当选择一行时, 根据之前设置了的行为, indexlist.size()就等于该行所拥有的总列数. 而当把函数换成QItemSelectionModel::selectedRows()时便不会有这样的错误，因为这个函数是针对行的，选择了多少行即多少行。

void BankAccountMS::updateLogView() { if (!NDEBUG) cerr << "BankAccountMS::updateLogView()" << endl; QItemSelectionModel *selections = cardView->selectionModel(); // QModelIndexList indexlist = selections->selectedIndexes(); QModelIndexList indexlist = selections->selectedRows(); if (!NDEBUG) cerr << "indexlist.size(): " << indexlist.size() << endl; // get id list QModelIndex index; QString filter = QString("cardid IN ("); QString loglabel = QString(tr("&Log in card id")); QVector<int> idlist; foreach (index, indexlist) { if (!index.isValid()) continue; QSqlRecord record = cardModel->record(index.row()); int id = record.value("id").toInt(); filter += " " + QString("%1, ").arg(id); loglabel += QString(": %1").arg(id); idlist.push_back(id); if (!NDEBUG) cerr << id << ", "; } filter += QString("-1)"); if (!NDEBUG) { // cerr << "filter: " << filter << endl; // cerr << "loglabel: " << loglabel << endl; } logModel->setFilter(filter); // logLabel->setText(loglabel); logLabel->setText(tr("&Log")); logModel->select(); logView->horizontalHeader()->setVisible(logModel->rowCount() > 0); }