博客

Qt之画刻度尺入门

效果图



上源码

#include "rulerslider.h"
#include "QPainter"
#include "math.h"

#include <QDebug>
#include <QEvent>
#include <QMouseEvent>

RulerSlider::RulerSlider(QWidget *parent):QSlider(parent)

{
   

    //注册过滤器

    installEventFilter(this);

    //鼠标事件追踪

    setMouseTracking(true);

    //显示当前值label

    valueLabel = new QLabel(this);

    valueLabel->setStyleSheet("background-color: rgb(0, 0, 0);font-size:14px;color:white;border:1px solid black");

    valueLabel->setAlignment(Qt::AlignCenter);

    valueLabel->hide();

    //滑块

    handleLabel = new QLabel(this);

    handleLabel->setFixedSize(20,15);

    handleLabel->raise();

    QImage image,result;

    image.load(":/images/handle.png");//temppath为图片的路径

    result = image.scaled(handleLabel->width(), handleLabel->height(),Qt::IgnoreAspectRatio, Qt::SmoothTransformation);//放缩图片，以固定大小显示

    handleLabel->setPixmap(QPixmap::fromImage(result));//在Label控件上显示图片

}

RulerSlider::~RulerSlider()

{
   

}

/**

* 绘制

* @brief RulerSlider::paintEvent

*/

void RulerSlider::paintEvent(QPaintEvent *)

{
   

    QPainter painter;

    painter.begin(this);

    //抗锯齿

    painter.setRenderHint(QPainter::Antialiasing);

    drawRulerBackgroud(&painter);

    drawSliderMark(&painter);

    painter.end();

}

/**

* 绘制尺子背景

* @brief RulerSlider::drawRulerBackgroud

* @param painter

*/

void RulerSlider::drawRulerBackgroud(QPainter *painter)

{
   

    QPointF topLeftPot3(0,0);

    QPointF bottomRightPot3(width(),height());

    painter->setPen(Qt::white);

    painter->setBrush(QColor(61,84,110));

    painter->drawRect(QRectF(topLeftPot3,bottomRightPot3));

}

/**

* 绘制刻度与值

* @brief RulerSlider::drawSliderMark

* @param painter

*/

void RulerSlider::drawSliderMark(QPainter *painter)

{
   

    painter->setPen(Qt::gray);

    painter->setBrush(QColor(128,128,128)