使 QListWidget 只显示 1 项

发布于 2024-10-05 06:11:01 字数 1810 浏览 12 评论 0原文

我创建了一个继承 QListWidget 的类，它是一堆卡片。

我已经重载了拖放功能，以允许将卡片拖到桌子上（我的程序的另一个对象），现在我偶然发现了另一个问题。

QListWidget 显示了我的所有项目（主要是因为我从一开始就将它们添加到 GUI 中）。

事情是这样的：在我的主窗口中，我初始化 CardPile 对象并用洗牌的卡片向量填充它。

现在我希望我的 QListWidget 仅显示一个（但它显示包含我所有卡片的网格）。

在放置时，我从 QListWidget 中删除该项目。但我不知道我是否要在代码中一次添加和删除一张卡（所以它当然只显示一张卡）。

public:
    TileStack(QWidget *parent = 0);
    void addCard(QPixmap pixmap, QPoint location);
    QPixmap showCard();

protected:
    void dragEnterEvent(QDragEnterEvent *event);
    void dragMoveEvent(QDragMoveEvent *event);
    void startDrag(Qt::DropActions supportedActions); //in this function I remove the current item

这些是我的 CardPile 中的函数：QListWidget。

所以：

void TileStack::startDrag(Qt::DropActions /*supportedActions*/)
{
    QListWidgetItem *item = currentItem();

    QByteArray itemData;
    QDataStream dataStream(&itemData, QIODevice::WriteOnly);
    QPixmap pixmap = qVariantValue<QPixmap>(item->data(Qt::UserRole));
    QPoint location = item->data(Qt::UserRole+1).toPoint();

    dataStream << pixmap << location;

    QMimeData *mimeData = new QMimeData;
    mimeData->setData("card", itemData);

    QDrag *drag = new QDrag(this);
    drag->setMimeData(mimeData);
    drag->setHotSpot(QPoint(pixmap.width()/2, pixmap.height()/2));
    drag->setPixmap(pixmap);

    if (drag->exec(Qt::MoveAction) == Qt::MoveAction)
        delete takeItem(row(item));
    //should I also make the add to the next item here? and how exactly should I put it     here?
}

因为我目前在主窗口中有我的洗牌向量（我在 forloop 中添加所有牌）。

或者我应该在主窗口和 CardPile 之间创建一个连接的信号和插槽 - 所以当

delete takeItem(row(item));

被调用时我会发出一个信号，表示将下一张卡添加到列表中？

感谢您的反馈

原文

I have created a class that inherits the QListWidget and is meant to be a stack of cards.

I have overloaded the drag and drop functions to allow a card to be dragged to the table (another object of my program) and now I stumble on another problem.

The QListWidget shows all my items (mainly because I add them to the GUI from the beginning).

So this is how it goes:
in my mainwindow I initialise my CardPile object and fill it up with a shuffled vector of cards.

Now I want my QListWidget to show only one (but its showing a grid with all my cards).

On a drop I remove the item from my QListWidget. But I have no idea if I were to add and remove 1 card at a time (so it only shows 1 card ofcourse) in my code.

public:
    TileStack(QWidget *parent = 0);
    void addCard(QPixmap pixmap, QPoint location);
    QPixmap showCard();

protected:
    void dragEnterEvent(QDragEnterEvent *event);
    void dragMoveEvent(QDragMoveEvent *event);
    void startDrag(Qt::DropActions supportedActions); //in this function I remove the current item

These are the functions in my CardPile : QListWidget.

so:

void TileStack::startDrag(Qt::DropActions /*supportedActions*/)
{
    QListWidgetItem *item = currentItem();

    QByteArray itemData;
    QDataStream dataStream(&itemData, QIODevice::WriteOnly);
    QPixmap pixmap = qVariantValue<QPixmap>(item->data(Qt::UserRole));
    QPoint location = item->data(Qt::UserRole+1).toPoint();

    dataStream << pixmap << location;

    QMimeData *mimeData = new QMimeData;
    mimeData->setData("card", itemData);

    QDrag *drag = new QDrag(this);
    drag->setMimeData(mimeData);
    drag->setHotSpot(QPoint(pixmap.width()/2, pixmap.height()/2));
    drag->setPixmap(pixmap);

    if (drag->exec(Qt::MoveAction) == Qt::MoveAction)
        delete takeItem(row(item));
    //should I also make the add to the next item here? and how exactly should I put it     here?
}

Because I currently have my vector of shuffled cards in the mainwindow (where I add all the cards in a forloop).

Or should I make a signal and slot that connect between mainwindow and CardPile - so when