使用QStyledItemDelegate時QPushButton的繪制方法面臨問題

需要幫忙...

uj5u.com熱心網友回復：

必須單擊單元格 3 次才能更改值的原因是因為您需要雙擊編輯（創建編輯器）并再次單擊呼叫UpdateUseButton。您不需要這樣做，您可以在創建編輯器時執行單擊。實際上，您甚至不需要 .，UpdateUseButton因為您可以在setModelData. 將以下插槽添加到您的PushButtonDelegate:

void commitAndCloseEditor();

然后像這樣實作類：

QWidget* PushButtonDelegate::createEditor(QWidget* parent, const QStyleOptionViewItem& option, const QModelIndex& index) const
{
    if (index.model()->headerData(index.column(), Qt::Horizontal, Qt::DisplayRole).toString() == constants::kUse)
    {
        const auto btn = new QPushButton(parent);
        const auto value = index.data().toString();
        btn->setCheckable(true);
        btn->setChecked(value == "Yes" ? true : false);
        btn->setFocusPolicy(Qt::NoFocus);
        
        // You don't need this, you can update your data in setModelData instead
        // connect(btn, SIGNAL(clicked(bool)), this, SLOT(UpdateUseButton(bool)));
        
        // the click will commit the data and close the editor
        // we connect it with a queued connection so that the slot is called after this function exits
        connect(btn, &QPushButton::clicked, this, &PushButtonDelegate::commitAndCloseEditor, Qt::QueuedConnection);
        emit btn->clicked(false); // perform a click programatically to that the commitAndCloseEditor will be called after we exit this function 
        return btn;
    }
    else
    {
        return QStyledItemDelegate::createEditor(parent, option, index);
    }
}

void PushButtonDelegate::setEditorData(QWidget* editor, const QModelIndex& index) const
{
    if (index.model()->headerData(index.column(), Qt::Horizontal, Qt::DisplayRole).toString() == constants::kUse)
    {
        //nothing to do when you are in your delegate column
    }
    else
    {
        QStyledItemDelegate::setEditorData(editor, index);
    }
}

void PushButtonDelegate::setModelData(QWidget* editor, QAbstractItemModel* model, const QModelIndex& index) const
{
    if (index.model()->headerData(index.column(), Qt::Horizontal, Qt::DisplayRole).toString() == constants::kUse)
    {
        // set your model data here
        model->setData(index, (index.data().toString() == "Yes") ? "No" : "Yes");
    }
    else
    {
        QStyledItemDelegate::setModelData(editor, model, index);
    }
}

void PushButtonDelegate::commitAndCloseEditor()
{
    auto* editor = qobject_cast<QWidget*>(sender());
    emit commitData(editor);
    emit closeEditor(editor);
}

請注意，我使用 aQt::QueuedConnnection來連接clicked信號。這確保了commitAndCloseEditor插槽將在兩者之后被createEditor呼叫setEditorData退出（通過在每個函式的開頭使用 print 陳述句很容易檢查）。如果您洗掉排隊的連接，則將在回傳實際編輯器commitAndCloseEditor之前呼叫createEditor，因此該插槽將不會執行任何操作，因為編輯器尚未打開。

現在，對于該paint方法......這似乎btn_->setChecked是未在按鈕中正確顯示背景顏色的原因。我不確定它為什么會這樣，但一種解決方法是使用這樣的樣式表：

void PushButtonDelegate::paint(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const
{
    if (index.model()->headerData(index.column(), Qt::Horizontal, Qt::DisplayRole).toString() == constants::kUse)
    {
        painter->save();
        btn_->setGeometry(option.rect);
        const auto value = index.data().toString();
        
        btn_->setText(value);
        
        QString stylesheet = QString("background-color: %1").arg((value == "Yes") ? "green" : "red"  );
        btn_->setStyleSheet(stylesheet);

        const QPixmap map = btn_->grab();
        painter->drawPixmap(option.rect.x(), option.rect.y(), map);

        painter->restore();
    }
    else
    {
        QStyledItemDelegate::paint(painter, option, index);
    }
}

現在應該通過雙擊切換值，結果（在我的 Windows 框中）如下所示：

標籤：C qt小部件qt5

上一篇：Ubuntu18.04上的PySide6分段錯誤（重新鏈接問題）

下一篇：如何禁用和重新啟用QPushButton