重新实现paintEvent()函数。
效果如下：
效果为蓝色区域，背景是vs接面，代码直接复制可用，留给有需要的人。
#ifndef CircleWidget_h__
#define CircleWidget_h__#include <QWidget>class CCircleWidget : public QWidget
{Q_OBJECTpublic:explicit CCircleWidget(QWidget* parent = 0); // explicit 避免歧义CCircleWidget(const QString& strImagePath, int nRadius, QWidget* parent = 0);public:void SetNormalOutLineColor(QColor color);void SetHoverOutLineColor(QColor color);void SetPressedOutLineColor(QColor color);void SetOutLineWidth(int nWidth);void SetImagePath(const QString& strImagePath);void SetHovered(bool bHovered);void SetPressed(bool bPressed);protected: // overridevoid Init();void paintEvent(QPaintEvent*) override; // 绘图事件，调用update()时触发void mousePressEvent(QMouseEvent* e) override; // 鼠标按下事件void mouseReleaseEvent(QMouseEvent* e) override; // 鼠标释放事件void enterEvent(QEvent*) override; // 鼠标进入事件void leaveEvent(QEvent*) override; // 鼠标离开事件signals:void SigClicked(); // 点击信号private:QString m_strImagePath; // 图片路径QColor m_normalColor;QColor m_hoverColor;QColor m_pressedColor;int m_nWidth;int m_nRadius; // 圆形半径bool m_bPressed; // 左键单击控制bool m_bHovered; // 鼠标悬停控制
};#endif // CircleWidget_h__#include "CircleWidget.h"
#include <QPainter>
#include <QMouseEvent>CCircleWidget::CCircleWidget(QWidget* parent): QWidget(parent), m_strImagePath(":/dotnetIcon.png"), m_normalColor("#58a3ef"), m_hoverColor("#6eb8f5"), m_pressedColor("#417cac"), m_nWidth(4), m_nRadius(46), m_bPressed(false), m_bHovered(false)
{Init();
}CCircleWidget::CCircleWidget(const QString& strImagePath, int nRadius, QWidget* parent): QWidget(parent), m_strImagePath(strImagePath), m_normalColor("#58a3ef"), m_hoverColor("#6eb8f5"), m_pressedColor("#417cac"), m_nWidth(4), m_nRadius(nRadius), m_bPressed(false), m_bHovered(false)
{Init();
}void CCircleWidget::SetNormalOutLineColor(QColor color)
{m_normalColor = color;
}void CCircleWidget::SetHoverOutLineColor(QColor color)
{m_hoverColor = color;
}void CCircleWidget::SetPressedOutLineColor(QColor color)
{m_pressedColor = color;
}void CCircleWidget::SetOutLineWidth(int nWidth)
{m_nWidth = nWidth;
}void CCircleWidget::SetImagePath(const QString& strImagePath)
{m_strImagePath = strImagePath;
}void CCircleWidget::SetHovered(bool bHovered)
{m_bHovered = bHovered;update();
}void CCircleWidget::SetPressed(bool bPressed)
{m_bPressed = bPressed;update();
}void CCircleWidget::Init()
{// 无边框setWindowFlags(Qt::FramelessWindowHint);// 窗口背景透明setAttribute(Qt::WA_TranslucentBackground, true);
}void CCircleWidget::paintEvent(QPaintEvent*)
{QPainter p(this);p.setRenderHint(QPainter::Antialiasing);QPen pen;pen.setWidth(m_nWidth);if (m_bPressed){pen.setColor("#417cac"); // 按下时的边框颜色}else if (m_bHovered){pen.setColor("#6eb8f5"); // 悬停时的边框颜色}else{pen.setColor("#58a3ef"); // 正常状态的边框颜色}p.setPen(pen);p.setBrush(Qt::NoBrush);// 设置圆心为圆的半径，以确保圆形完整显示//QPoint center(m_nRadius + m_nWidth / 2, m_nRadius + m_nWidth / 2);QPoint center(rect().center());// 绘制背景圆形p.drawEllipse(center, m_nRadius, m_nRadius);// 绘制图片QPixmap pixmap(m_strImagePath);QRect imageRect(0, 0, 2 * m_nRadius, 2 * m_nRadius); // 计算图片绘制区域QPainterPath clipPath;clipPath.addEllipse(center, m_nRadius, m_nRadius);p.setClipPath(clipPath);p.drawPixmap(center.x() - m_nRadius, center.y() - m_nRadius, imageRect.width(), imageRect.height(), pixmap);
}void CCircleWidget::mousePressEvent(QMouseEvent* e)
{m_bPressed = true;update();
}void CCircleWidget::mouseReleaseEvent(QMouseEvent* e)
{m_bPressed = false;update();
}void CCircleWidget::enterEvent(QEvent*)
{m_bHovered = true;update();
}void CCircleWidget::leaveEvent(QEvent*)
{m_bHovered = false;update();
}