南通网站设计专家,百度只收录栏目不收录网站文章,陕西建设工程合同备案网站,教育局网站群建设方案实现背景#xff1a; Qt本身有自己的QSlider#xff0c;为什么我们还要自定义实现呢#xff0c;因为Qt自带的QSlider存在一个问题#xff0c;当首尾为圆角时#xff0c;滑动滚动条到首尾时会出现圆角变成矩形的问题。当然如果QSS之间的margin和滑动条的圆角控制的好的话是…实现背景 Qt本身有自己的QSlider为什么我们还要自定义实现呢因为Qt自带的QSlider存在一个问题当首尾为圆角时滑动滚动条到首尾时会出现圆角变成矩形的问题。当然如果QSS之间的margin和滑动条的圆角控制的好的话是不会出现这个问题的但是我们一般都是按照美工设计来完成工作的如果她的设计是必须一摸一样的话这个margin和圆角配合不了出现以上问题的话那我们就需要实现一个自定义的QSlider了。
实现思路 1、继承QWidget或者QSlider都可以当然如果我们继承QSlider的话那还不如使用重写QStyle的方式来重绘。 2、使用paintevent绘制事件来进行重绘。 3、配合mouse鼠标事件实现拖动功能。 4、配合resizeEvent事件来实现自适应大小。
实现效果
实现代码 头文件
#ifndef WIDGET_H
#define WIDGET_H#include QWidget
#include QPainter
#include QMouseEventclass Widget : public QWidget
{Q_OBJECTpublic:explicit Widget(QWidget *parent nullptr);~Widget();void reset(); //复位void setDirection(int dire){m_direction dire;}
protected:void mousePressEvent(QMouseEvent *event);void mouseMoveEvent(QMouseEvent *event);void mouseReleaseEvent(QMouseEvent *event);void resizeEvent(QResizeEvent *event);void paintEvent(QPaintEvent *event);
signals:void sig_Run();
private:QRect m_handleRect;bool m_pressFlag false;bool m_autoFg false;int m_lastX 0;int m_lastY 0;int m_direction 0; //0:水平1:垂直QPixmap m_handlepix;
};#endif // WIDGET_H
cpp文件
#include widget.h
#include QDebug
Widget::Widget(QWidget *parent) :QWidget(parent)
{}Widget::~Widget()
{
}void Widget::resizeEvent(QResizeEvent *event)
{if (m_direction 0)m_handleRect QRect(1,1,height(),height() - 2);elsem_handleRect QRect(1,height() - width(),width(),width() - 2);
}
void Widget::paintEvent(QPaintEvent *event)
{QPainter p(this);p.setRenderHint(QPainter::Antialiasing);p.setPen(QColor(#ffffff));p.setBrush(QColor(#ffffff));if (m_direction 0)p.drawRoundedRect(this-rect(),height()/2,height()/2);elsep.drawRoundedRect(this-rect(),width()/2,width()/2);//滑轨前半部分QLinearGradient linearGradient(QPoint(0,0),QPoint(0,height()));linearGradient.setColorAt(0,QColor(#56B478));linearGradient.setColorAt(0.7,QColor(#006009));linearGradient.setColorAt(1,QColor(#56B478));QBrush brush(linearGradient);p.setBrush(brush);if (m_direction 0)p.drawRoundedRect(QRect(1,1,m_handleRect.right(),height()-2),height()/2,height()/2);elsep.drawRoundedRect(QRect(1,1,width(),m_handleRect.bottom()-2),width()/2,width()/2);//滑轨后半部分QBrush brush1(QColor(#606060));p.setBrush(brush1);if (m_direction 0)p.drawRoundedRect(QRect(m_handleRect.left(),1,width() - m_handleRect.left() - 2,height()-2),height()/2,height()/2);elsep.drawRoundedRect(QRect(1,m_handleRect.top(),width()-2,height() - m_handleRect.top()),width()/2,width()/2);//文本p.setPen(QColor(#ffffff));p.setBrush(QColor(#ffffff));p.setFont(QFont(Microsoft YaHei,8));p.drawText(2*width()/3,0,width()/3,height(),Qt::AlignCenter,进度条);//滑动块// p.drawPixmap(m_handleRect,m_handlepix);p.setPen(QColor(#ffffff));p.setBrush(QColor(#842245));p.drawEllipse(m_handleRect);
}void Widget::mousePressEvent(QMouseEvent *event)
{qDebug()m_handleRectevent-pos();if (m_handleRect.contains(event-pos())){m_pressFlag true;}}void Widget::mouseMoveEvent(QMouseEvent *event)
{if (m_pressFlag){if (m_direction 0){int x event-x();if (event-x() this-rect().right())x this-rect().right() - 1;qDebug()xm_lastXwidth();if (x this-rect().right() - m_handleRect.width())x this-rect().right() - m_handleRect.width();if (x 0)x 0;m_handleRect QRect(x,m_handleRect.y(),m_handleRect.width(),m_handleRect.height());if (m_autoFg){if (x m_lastX m_handleRect.right() this-rect().right() - width()/3){m_handleRect QRect(this-rect().width() - m_handleRect.width() - 1,m_handleRect.y(),m_handleRect.width(),m_handleRect.height());}else if (m_handleRect.left() 0)m_handleRect QRect(1,m_handleRect.y(),m_handleRect.width(),m_handleRect.height());m_lastX x;}}else{int y event-y();if (event-y() this-rect().bottom())y this-rect().bottom() - 1;if (y this-rect().bottom() - m_handleRect.height())y this-rect().bottom() - m_handleRect.height();if (y 0)y 0;m_handleRect QRect(m_handleRect.x(),y,m_handleRect.width(),m_handleRect.height());if (m_autoFg){if (y m_lastY m_handleRect.top() height()/3){m_handleRect QRect(m_handleRect.x(),1,m_handleRect.width(),m_handleRect.height());}m_lastY y;}}update();}
}void Widget::mouseReleaseEvent(QMouseEvent *event)
{//autoif (m_autoFg){if (m_handleRect.right() ! this-rect().right() - 1){m_handleRect QRect(1,m_handleRect.y(),m_handleRect.width(),m_handleRect.height());update();}else {emit sig_Run();}}elseemit sig_Run();m_pressFlag false;}void Widget::reset()
{m_handleRect QRect(1,m_handleRect.y(),m_handleRect.width(),m_handleRect.height());update();
}
