c++ - 使用 QScrollArea 滚动条

Question

我在 Qt Designer 中创建了两个滚动区域。它们每个的大小分别为 [(31,48) 1141 x 161] 和 [(31, 310) 1141 x 101]。然后我创建了两个 TimeDiagram 类的小部件拷贝，我将它们的大小设置为大于各自滚动区域的大小。然后我将对象设置为区域。启用垂直和水平滚动条。

窗口的构造函数:

GraphicScaleDialog::GraphicScaleDialog(OutputData *outputData, QWidget *parent) :
    QDialog(parent),
    ui(new Ui::GraphicScaleDialog) {
    ui->setupUi(this);

    data = outputData;

    commonSAGridSpacing = 120;
    commonSAScale = 15;
    resultsSAGridSpacing = 120;
    resultsSAScale = 15;

    ui->commonSAGridSpacing_line->setText(QString::number(commonSAGridSpacing));
    ui->commonSAScale_line->setText(QString::number(commonSAScale));
    ui->resultsSAGridSpacing_line->setText(QString::number(resultsSAGridSpacing));
    ui->resultsSAScale_line->setText(QString::number(resultsSAScale));

    commonArea = ui->commonScrollArea;
    commonArea->setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);
    commonArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAsNeeded);
    resultsArea = ui->resultsScrollArea;
    resultsArea->setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);
    resultsArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAsNeeded);

    commonDiagramWidget = new TimeDiagram(20, this);
    commonDiagramWidget->setGeometry(31, 41, 2000, static_cast<int>(data->outputSettings.flowQuantity * commonDiagramWidget->rowHeight));
    resultsDiagramWidget = new TimeDiagram(100, this);
    resultsDiagramWidget->setGeometry(31, 114, 2000, 101);

    commonArea->setWidget(commonDiagramWidget);
    resultsArea->setWidget(resultsDiagramWidget);

    commonArea->show();
    resultsArea->show();
}

问题是创建两个带有时间轴的网格​​。

我需要使用 QPainter 来解决这个问题吗？

更新:可能是 TimeDiagram 的方法有问题？

void TimeDiagram::paintEvent(QPaintEvent * /* event */) {
    QPainter  painter(this);
    draw(&painter);
}

//--------------------------------------------------------------

void TimeDiagram::draw(QPainter *painter) {
    painter->setRenderHint(QPainter ::NonCosmeticDefaultPen, true);
    QPen* pen = new QPen();
    pen->setWidth(1);

    pen->setColor(Qt::black);
    painter->setPen(*pen);
    for (int i = static_cast<int>(rowHeight); i < this->height(); i += static_cast<int>(rowHeight))
    //for (unsigned int counter = 0; counter < static_cast<GraphicScaleDialog *>(this->parent())->data->outputSettings.flowQuantity; counter++)
        painter->drawLine(0, i, this->width(), i);

    pen->setColor(Qt::lightGray);
    painter->setPen(*pen);
    for(int i = 0; i < this->width(); i += 30)
      painter->drawLine(i, 0, i, this->height());

    delete pen;
}

Answer 1

在 Designer 中，在您的 QScrollArea 中取消选中 widgetResizable 属性或使用 QScrollArea::setWidgetResizable 以编程方式将其关闭。