C++ QLabel在项委托（QStyledItemDelegate）上呈现时不透明

我有一个奇怪的问题，我让项目委托从QStyledItemDelegate继承 背景色为渐变色，如下所示：

void ItemDelegate::paintActiveOverlay( QPainter* painter,
                                       qreal x,
                                       qreal y,
                                       qreal w,
                                       qreal h ) const 
{
    QPalette palette;
    QColor highlightColor = palette.color(QPalette::Highlight);
    QColor backgroundColor = palette.color(QPalette::Base);
    const float animation = 0.25;
    const int gradientRange = 16;

    QColor color2 = QColor::fromHsv(
        highlightColor.hue(),
        (int) (backgroundColor.saturation() * (1.0f - animation) + 
        highlightColor.saturation() * animation),
        (int) (backgroundColor.value() * (1.0f - animation) + 
        highlightColor.value() * animation) );

    QColor color1 = QColor::fromHsv(
        color2.hue(),
        qMax(color2.saturation() - gradientRange, 0),
        qMin(color2.value() + gradientRange, 255) );

    QRect rect( (int)x, (int)y, (int)w, (int)h);

    painter->save();
    painter->setPen(Qt::NoPen);

    QLinearGradient linearGradient(0, 0, 0, rect.height());
    linearGradient.setColorAt(0.0, color1);
    linearGradient.setColorAt(1.0, color2);

    painter->setBrush(linearGradient);
    painter->drawRect(rect);
    painter->restore();
}

 QRect rect(40, 30, 401, 31);
 Qt::TextInteractionFlags flags =     
      Qt::LinksAccessibleByKeyboard | 
      Qt::LinksAccessibleByMouse    |
      Qt::TextBrowserInteraction    |
      Qt::TextSelectableByKeyboard  |
      Qt::TextSelectableByMouse;
 Qt::TextFormat txtFormat = Qt::PlainText;

 pTextEdit_title = new QLabel();
 pTextEdit_title->setTextFormat(txtFormat);
 pTextEdit_title->setTextInteractionFlags(flags);
 pTextEdit_title->setGeometry(rect);

  pTextEdit_title->setText(Title);
  QRect TextEditRect(option.rect.x()+THUMB_WIDTH+THUMB_WIDTH+PADDING, option.rect.y() ,
  pTextEdit_title->width(), pTextEdit_title->height());
  QPixmap pixmap(pTextEdit_title->size());
  pTextEdit_title->render(&pixmap);
  painter->drawPixmap(TextEditRect,pixmap);

它是从paint方法调用的，也是在ItemDelegate构造函数中调用的，我将QLabel设置为：

void ItemDelegate::paintActiveOverlay( QPainter* painter,
                                       qreal x,
                                       qreal y,
                                       qreal w,
                                       qreal h ) const 
{
    QPalette palette;
    QColor highlightColor = palette.color(QPalette::Highlight);
    QColor backgroundColor = palette.color(QPalette::Base);
    const float animation = 0.25;
    const int gradientRange = 16;

    QColor color2 = QColor::fromHsv(
        highlightColor.hue(),
        (int) (backgroundColor.saturation() * (1.0f - animation) + 
        highlightColor.saturation() * animation),
        (int) (backgroundColor.value() * (1.0f - animation) + 
        highlightColor.value() * animation) );

    QColor color1 = QColor::fromHsv(
        color2.hue(),
        qMax(color2.saturation() - gradientRange, 0),
        qMin(color2.value() + gradientRange, 255) );

    QRect rect( (int)x, (int)y, (int)w, (int)h);

    painter->save();
    painter->setPen(Qt::NoPen);

    QLinearGradient linearGradient(0, 0, 0, rect.height());
    linearGradient.setColorAt(0.0, color1);
    linearGradient.setColorAt(1.0, color2);

    painter->setBrush(linearGradient);
    painter->drawRect(rect);
    painter->restore();
}

 QRect rect(40, 30, 401, 31);
 Qt::TextInteractionFlags flags =     
      Qt::LinksAccessibleByKeyboard | 
      Qt::LinksAccessibleByMouse    |
      Qt::TextBrowserInteraction    |
      Qt::TextSelectableByKeyboard  |
      Qt::TextSelectableByMouse;
 Qt::TextFormat txtFormat = Qt::PlainText;

 pTextEdit_title = new QLabel();
 pTextEdit_title->setTextFormat(txtFormat);
 pTextEdit_title->setTextInteractionFlags(flags);
 pTextEdit_title->setGeometry(rect);

  pTextEdit_title->setText(Title);
  QRect TextEditRect(option.rect.x()+THUMB_WIDTH+THUMB_WIDTH+PADDING, option.rect.y() ,
  pTextEdit_title->width(), pTextEdit_title->height());
  QPixmap pixmap(pTextEdit_title->size());
  pTextEdit_title->render(&pixmap);
  painter->drawPixmap(TextEditRect,pixmap);

在ItemDelegate的paint方法中，我将QLabel设置为如下方式渲染：

void ItemDelegate::paintActiveOverlay( QPainter* painter,
                                       qreal x,
                                       qreal y,
                                       qreal w,
                                       qreal h ) const 
{
    QPalette palette;
    QColor highlightColor = palette.color(QPalette::Highlight);
    QColor backgroundColor = palette.color(QPalette::Base);
    const float animation = 0.25;
    const int gradientRange = 16;

    QColor color2 = QColor::fromHsv(
        highlightColor.hue(),
        (int) (backgroundColor.saturation() * (1.0f - animation) + 
        highlightColor.saturation() * animation),
        (int) (backgroundColor.value() * (1.0f - animation) + 
        highlightColor.value() * animation) );

    QColor color1 = QColor::fromHsv(
        color2.hue(),
        qMax(color2.saturation() - gradientRange, 0),
        qMin(color2.value() + gradientRange, 255) );

    QRect rect( (int)x, (int)y, (int)w, (int)h);

    painter->save();
    painter->setPen(Qt::NoPen);

    QLinearGradient linearGradient(0, 0, 0, rect.height());
    linearGradient.setColorAt(0.0, color1);
    linearGradient.setColorAt(1.0, color2);

    painter->setBrush(linearGradient);
    painter->drawRect(rect);
    painter->restore();
}

 QRect rect(40, 30, 401, 31);
 Qt::TextInteractionFlags flags =     
      Qt::LinksAccessibleByKeyboard | 
      Qt::LinksAccessibleByMouse    |
      Qt::TextBrowserInteraction    |
      Qt::TextSelectableByKeyboard  |
      Qt::TextSelectableByMouse;
 Qt::TextFormat txtFormat = Qt::PlainText;

 pTextEdit_title = new QLabel();
 pTextEdit_title->setTextFormat(txtFormat);
 pTextEdit_title->setTextInteractionFlags(flags);
 pTextEdit_title->setGeometry(rect);

  pTextEdit_title->setText(Title);
  QRect TextEditRect(option.rect.x()+THUMB_WIDTH+THUMB_WIDTH+PADDING, option.rect.y() ,
  pTextEdit_title->width(), pTextEdit_title->height());
  QPixmap pixmap(pTextEdit_title->size());
  pTextEdit_title->render(&pixmap);
  painter->drawPixmap(TextEditRect,pixmap);

它渲染QLabel文件，但问题是它有灰色背景，不能作为透明背景，我的问题是如何将QLabel背景设置为透明？

---

另外，我设置的TextInteractionFlags被忽略的原因是，我无法对文本执行任何操作。

颜色透明度取决于：

颜色的alpha通道指定透明度效果0 表示完全透明的颜色，而255表示完全透明的颜色 不透明的颜色

默认情况下，它是255，因此您应该在正在使用的函数中指定所需的值作为第四个参数

---

或者，您可以使用该函数。

呈现小部件时，始终绘制小部件背景。有一个特殊的渲染标志来禁用小部件背景的渲染

---

qwidget api手册中对此进行了解释。

是的，我使用了：QPalette pptexEdit_title->palette；//将背景颜色设置为黑色p.setColorQPalette:：background，Qt:：transparent；pTextEdit_title->setPalettep；还是灰色的背景…我该怎么做？我没有找到任何教程？我尝试实现以下内容：。但它仍然是灰色的，我怀疑这与我设置的项目背景颜色有关