如何在QTableView中显示QAbstractItemModel的子行 [英] How to display sub-rows of QAbstractItemModel in QTableView

问题描述

我有我自己的类继承自QAbstractItemModel它有树结构。

I have my own class that inherits from QAbstractItemModel which has tree structure.

我使用几个视图，使用从QSortFilterProxyModel派生的类显示此模型的过滤数据。

I use a couple of views, that display filtered data of this model, using classes derived from QSortFilterProxyModel.

我的模型结构如下：

root
|
-- A
|  |-A1
|  |-A2
|  |-A3
|
-- B
|  |-B1
|  |-B2
|
... and so on...

其中A，B ....是主行（根的子代），A1，A2，... B1，B2 ...是子行 - 附加到主行的节点行。

Where A, B .... are "main rows" (children of the root), and A1, A2, ... B1, B2... are "children rows" - node rows appended to "main rows".

现在，我需要做的是只显示子行的QTableView：

Now, what I need to do is a QTableView that displays "children rows" only:

A1
A2
A3
B1
B2

方法我发现在QSortFilterProxyModel（filterAcceptsRow，filterAcceptsColumn），只操作主行...

But filtering methods I found in QSortFilterProxyModel (filterAcceptsRow, filterAcceptsColumn), operates on main rows only...

我如何做？

（我发现非常相似的问题，但它仍然没有回答： QTableView只显示用QAbstractItemModel实现的树模型的叶子）

(I found very similar question, but it is still unanswered: QTableView to display only leaves of a tree model implemented with QAbstractItemModel)

推荐答案

p>我看到这个问题的3个可能的解决方案。前两个解决方案在对此问题的评论中提供了 Dmitry Sazonov ：

I see 3 possible solutions for this problem. First two solutions offered Dmitry Sazonov in his comment for this question:

1. 重新实现 QAbstractProxyModel 。


2. 重新实现 QAbstractItemModel 并为此类视图创建另一个模型。

1. Reimplement QAbstractProxyModel.
2. Reimplement QAbstractItemModel and create another model for such view.

第三种可能的解决方案是重新实现 QStyledItemDelegate 。我为这样的解决方案做一个小例子。我希望这将是有用的：

The third possible solution is little trick with reimplementation of QStyledItemDelegate for view. I make small example for such solution. I hope, it will be useful:

#include <QApplication>
#include <QTreeView>
#include <QStyledItemDelegate>
#include <QStandardItemModel>

class ZeroHightItemDelegate : public QStyledItemDelegate
{
    Q_OBJECT
public:
    ZeroHightItemDelegate(QObject* parent = 0)
        : QStyledItemDelegate(parent)
    {}
    ~ZeroHightItemDelegate(){}
public:
    QSize sizeHint(const QStyleOptionViewItem & option, const QModelIndex & index) const Q_DECL_OVERRIDE
    {
        static int defaultHeight = 0;
        static bool firstSizeHintFlag = true;
        QSize size = QStyledItemDelegate::sizeHint(option, index);
        if (firstSizeHintFlag){
            defaultHeight = size.height();
            firstSizeHintFlag = false;
        }
        const QAbstractItemModel* model = index.model();
        if (!model)
            return size;
        if (model->hasChildren(index))
            size.setHeight(0);
        else
            size.setHeight(defaultHeight);
        return size;
    }
};


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

    QTreeView myView;
    myView.setRootIsDecorated(false);
    QStandardItemModel* model = new QStandardItemModel(&myView);
    myView.setModel(model);

    model->insertColumns(0, 1);
    QStandardItem* headerItem = new QStandardItem("Header");
    model->setHorizontalHeaderItem(0, headerItem);

    QStandardItem* itemA = new QStandardItem("A");
    model->appendRow(itemA);
    QStandardItem* itemB = new QStandardItem("B");
    model->appendRow(itemB);
    QStandardItem* itemA1 = new QStandardItem("A1");
    QStandardItem* itemA2 = new QStandardItem("A2");
    itemA->appendRow(itemA1);
    itemA->appendRow(itemA2);
    QStandardItem* itemB1 = new QStandardItem("B1");
    QStandardItem* itemB2 = new QStandardItem("B2");
    QStandardItem* itemB3 = new QStandardItem("B3");
    itemB->appendRow(itemB1);
    itemB->appendRow(itemB2);
    itemB->appendRow(itemB3);
    myView.setItemDelegate(new ZeroHightItemDelegate(&myView));

    myView.expandAll();
    myView.show();

    return a.exec();
}

#include "main.moc"

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