边框布局范例

Shows how to arrange child widgets along a border.

边框布局 implements a layout that arranges child widgets to surround the main area.

The constructor of the Window class creates a QTextBrowser object, to which a BorderLayout named layout is added. The declaration of the BorderLayout class is quoted at the end of this document.

Window::Window()
{
    QTextBrowser *centralWidget = new QTextBrowser;
    centralWidget->setPlainText(tr("Central widget"));
    BorderLayout *layout = new BorderLayout;
					

Several labeled widgets are added to layout with the orientation Center , North , West , East 1 , East 2 ，和 South .

    layout->addWidget(centralWidget, BorderLayout::Center);
    layout->addWidget(createLabel("North"), BorderLayout::North);
    layout->addWidget(createLabel("West"), BorderLayout::West);
    layout->addWidget(createLabel("East 1"), BorderLayout::East);
    layout->addWidget(createLabel("East 2") , BorderLayout::East);
    layout->addWidget(createLabel("South"), BorderLayout::South);
    setLayout(layout);
    setWindowTitle(tr("Border Layout"));
					

createLabel() in class Window sets the text of the labeled widgets and the style.

QLabel *Window::createLabel(const QString &text)
{
    QLabel *label = new QLabel(text);
    label->setFrameStyle(QFrame::Box | QFrame::Raised);
    return label;
}
					

Class BorderLayout contains all the utilitarian functions for formatting the widgets it contains.

class BorderLayout : public QLayout
{
public:
    enum Position { West, North, South, East, Center };
    explicit BorderLayout(QWidget *parent, const QMargins &margins = QMargins(), int spacing = -1);
    BorderLayout(int spacing = -1);
    ~BorderLayout();
    void addItem(QLayoutItem *item) override;
    void addWidget(QWidget *widget, Position position);
    Qt::Orientations expandingDirections() const override;
    bool hasHeightForWidth() const override;
    int count() const override;
    QLayoutItem *itemAt(int index) const override;
    QSize minimumSize() const override;
    void setGeometry(const QRect &rect) override;
    QSize sizeHint() const override;
    QLayoutItem *takeAt(int index) override;
    void add(QLayoutItem *item, Position position);
private:
    struct ItemWrapper
    {
        ItemWrapper(QLayoutItem *i, Position p) {
            item = i;
            position = p;
        }
        QLayoutItem *item;
        Position position;
    };
    enum SizeType { MinimumSize, SizeHint };
    QSize calculateSize(SizeType sizeType) const;
    QList<ItemWrapper *> list;
};
					

更多信息，拜访 布局管理 页面。

运行范例

要运行范例从 Qt Creator ，打开 Welcome 模式，然后选择范例从 Examples 。更多信息，拜访 构建和运行范例 .

范例工程 @ code.qt.io

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