Qt绘制形状不规则窗口（一）

环境配置 ：MinGW + QT 5.12

效果图：

其实这个缩略图就是模仿Chrome书签栏拖拽书签时的缩略图（如下图所示）。主要是重写QWidget的paintEvent函数。

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thumbnail类继承自QWidget

• thumbnail.h文件

#define RADIUS 17             //窗口边角的弧度
#define ELLIPSE_RADIUS 12     //内部小圆半径
#define RECT 10               //图标长/宽的一半
#define TEXT_LENGTH 100       //文字长度

class thumbnail : public QWidget
{
    Q_OBJECT
public:
    thumbnail(QWidget *parent = nullptr);
    void setupthumbnail(QIcon icon, QString str);
    void setIconSize(int size);

private:
    QPushButton *ImageButton = nullptr;
    QLabel *TextLabel = nullptr;

private:
    void initUi();
    void paintEvent(QPaintEvent *);
};

• thumbnail.c文件

thumbnail::thumbnail(QWidget *parent) :
    QWidget(parent)
{
    initUi();
}

void thumbnail::initUi()
{
    setWindowFlags(Qt::FramelessWindowHint);
    setAttribute(Qt::WA_TranslucentBackground);

    setFixedSize(140, 34);

    ImageButton = new QPushButton(this);
    ImageButton->setFixedSize(20, 20);
    ImageButton->setIconSize(QSize(20, 20));
    ImageButton->setFlat(true);
    ImageButton->setStyleSheet("QPushButton{border:0px solid rgb(0, 0, 0);}");
    ImageButton->setFocusPolicy(Qt::NoFocus);
    ImageButton->move(RADIUS - RECT, RADIUS - RECT);

    TextLabel = new QLabel(this);
    TextLabel->setFixedSize(TEXT_LENGTH, 20);
    TextLabel->setAlignment(Qt::AlignVCenter);
    TextLabel->setFont(QFont("Microsoft YaHei", 8, QFont::Normal));
    TextLabel->setStyleSheet("QLabel{color:rgba(255, 255, 255, 255); border:0px solid rgb(0, 0, 0);}");
    TextLabel->setFocusPolicy(Qt::NoFocus);

    QHBoxLayout *layout = new QHBoxLayout(this);
    layout->setSpacing(0);
    layout->addWidget(TextLabel);
    layout->setContentsMargins(2 * RADIUS, 0, 0, 2);
}

void thumbnail::setupthumbnail(QIcon icon, QString text)
{
    ImageButton->setIcon(QIcon(icon));

    TextLabel->setText(text);
    int textSize = fontMetrics().width(text);  //字符超长检测
    if(textSize > TEXT_LENGTH){
        QString Elide_text = fontMetrics().elidedText(text, Qt::ElideRight, TEXT_LENGTH);
        TextLabel->setText(Elide_text);
    }
}

void thumbnail::setIconSize(int size)
{
    ImageButton->setIconSize(QSize(size, size));
}

void thumbnail::paintEvent(QPaintEvent *)
{
    QPainter Painter(this);
    Painter.setRenderHint(QPainter::Antialiasing, true);
    Painter.setPen(Qt::NoPen);
    Painter.setBrush(QColor(114, 164, 250, 200));

    QPainterPath PainterPath;
    PainterPath.addRoundedRect(QRect(0, 0, width(), height()), RADIUS, RADIUS);  //Rect
    PainterPath.addEllipse(RADIUS - ELLIPSE_RADIUS, RADIUS - ELLIPSE_RADIUS, ELLIPSE_RADIUS * 2, ELLIPSE_RADIUS * 2);  //除去内部小圆
    Painter.drawPath(PainterPath);

    Painter.setBrush(QColor(255, 255, 255, 200));
    Painter.drawEllipse(RADIUS - ELLIPSE_RADIUS, RADIUS - ELLIPSE_RADIUS, ELLIPSE_RADIUS * 2, ELLIPSE_RADIUS * 2);  //内部小圆重新上色
}

环境配置 ：MinGW + QT 5.12