Qt5利用QPainter实现水波纹进度条
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利用QPainter实现水波纹进度条。自定义一个继承自QWidget的类，并在其中重写paintEvent方法进行绘制操作。通过使用QPainter的绘制方法和一些算法，可以实现动态的水波纹效果。 #include "waterprocess.h"#include <QDebug>WaterProcess::WaterProcess(QWidget *parent) : QWidget(parent){ m_minValue = 0; m_maxValue = 100; m_value = 30; m_borderWidth = 10.0; m_waterHeight = 0.05; m_offset = 0.6; m_bgColor = QColor(120, 120, 120); m_borderColor = QColor(80, 80, 80); m_usedColor = QColor(50, 205, 50); m_textColor = QColor(255, 255, 255); //波浪 m_timer = new QTimer(this); m_timer->setInterval(100); connect(m_timer, &QTimer::timeout, this, &WaterProcess::updateWave); m_timer->start();}void WaterProcess::setUsedColor(const QColor color){ m_usedColor = color;}void WaterProcess::paintEvent(QPaintEvent *ev){ Q_UNUSED(ev) QPainter painter(this); painter.setRenderHints(QPainter::Antialiasing | QPainter::TextAntialiasing); //背景 drawBg(&painter); //进度、水波 drawProcess(&painter); //进度数字 drawValue(&painter);}void WaterProcess::drawBg(QPainter *painter){ int width = this->width(); int height = this->height(); int side = qMin(width, height) - m_borderWidth; int startX = (width - side) * 0.5; int startY = (height - side) * 0.5; painter->save(); painter->setBrush(QBrush(m_bgColor)); if (m_borderWidth == 0) { painter->setPen(Qt::NoPen); } else { QBrush brush(m_borderColor); painter->setPen(QPen(brush, m_borderWidth, Qt::SolidLine)); } painter->drawEllipse(startX, startY, side, side); painter->restore();}void WaterProcess::drawProcess(QPainter *painter){ int width = this->width(); int height = this->height(); int side = qMin(width, height) - (2 * m_borderWidth); //直径 int startX = (width - side) * 0.5; int startY = (height - side) *0.5; int endX = startX + side; int endY = startY + side; double percent = (m_value * 1.0) / (m_maxValue - m_minValue); double w = 2 * M_PI / endX; double A = endY * m_waterHeight; double k = endY * (1.0 - percent); painter->save(); painter->setPen(Qt::NoPen); painter->setBrush(m_usedColor); QPainterPath totalPath; //加入圆形路径 totalPath.addEllipse(startX, startY, side, side); //水波路径 QPainterPath water1; QPainterPath water2; water1.moveTo(startX, endY); water2.moveTo(startX, endY); m_offset += 0.6; if (m_offset > (endX / 2)) { m_offset = 0; } for(int i = startX; i < endX; i++) { //第一条波浪Y轴 double waterY1 = (double)(A * qSin(w * i + m_offset)) + k; //第二条波浪Y轴 double waterY2; waterY2 = (double)(A * qSin(w * i + m_offset + (endX / 2 * w))) + k; water1.lineTo(i, waterY1); water2.lineTo(i, waterY2); if (m_value == m_minValue) { waterY1 = endY; } if (m_value == m_maxValue) { waterY1 = startY; } } //封闭 water1.lineTo(endX, endY); water2.lineTo(endX, endY); QPainterPath path; QColor waterColor1 = m_usedColor; waterColor1.setAlpha(100); QColor waterColor2 = m_usedColor; waterColor2.setAlpha(200); //第一条波浪 path = totalPath.intersected(water1); painter->setBrush(waterColor1); painter->drawPath(path); //第二条波浪挖去后的路径 path = totalPath.intersected(water2); painter->setBrush(waterColor2); painter->drawPath(path); painter->restore();}void WaterProcess::drawValue(QPainter *painter){ painter->save(); int width = this->width(); int height = this->height(); int side = qMin(width, height) - m_borderWidth; int startX = (width - side) * 0.5; int startY = (height - side) * 0.5; int fontSize = side / 4; QFont font; font.setFamily("华文彩云"); font.setPixelSize(fontSize); font.setBold(true); painter->setFont(font); painter->setPen(Qt::white); painter->drawText(QRectF(startX, startY, side, side), Qt::AlignCenter, QString("%1%").arg(m_value)); painter->restore();}void WaterProcess::setMinValue(int value){ m_minValue = value; update();}void WaterProcess::setMaxValue(int value){ m_maxValue = value; update();}void WaterProcess::setValue(int v){ m_value = v; update();}void WaterProcess::setBorderWidth(int width){ m_borderWidth = width; update();}void WaterProcess::setWaterHeight(int height){ m_waterHeight = height; update();}void WaterProcess::start(){ if (m_timer) { m_timer->start(); }}void WaterProcess::stop(){ if (m_timer) { m_timer->stop(); }}void WaterProcess::updateWave(){ update();}