27.QT-QProgressBar动态实现多彩进度条(详解)

如下图所示:

效果如下:

(gif录制的动画效果不好,所以颜色有间隙)

 

介绍

通过qss实现,只需要一个多彩背景图,通过QImage获取颜色,然后来设置进度条,便可以实现动态多彩进度条(根据图片设定颜色)

其中,上面3个进度条就是通过以下3个图片实现的:

如果想实现其它颜色,只需要改图片即可

 

代码如下

ProgressBar.h:

#ifndef PROGRESSBAR_H #define PROGRESSBAR_H #include <QtGui>

class ProgressBar : public QWidget { Q_OBJECT QProgressBar m_bar; QLabel m_value; QSlider m_slider; QImage m_image; protected slots: void  onvalueChanged(int value); public: explicit ProgressBar(const QString&  fileName,QWidget *parent = 0); }; #endif // PROGRESSBAR_H

ProgressBar.cpp:

#include "ProgressBar.h" ProgressBar:: ProgressBar(const QString&  fileName,QWidget *parent ) : QWidget(parent), m_bar(this), m_value(this), m_slider(this), m_image(fileName) { m_bar.setMaximum(100); m_bar.setMinimum(0); m_bar.setValue(0); m_bar.setTextVisible(false); m_bar.setFixedHeight(20); m_slider.setMaximum(100); m_slider.setMinimum(0); m_slider.setValue(0); m_slider.setOrientation(Qt::Horizontal); m_value.setText(QString("%1%").arg(m_bar.value())); m_value.setAlignment(Qt::AlignRight|Qt::AlignVCenter); m_value.setMinimumWidth(40);
 /*设置布局*/ QHBoxLayout* hlayout = new QHBoxLayout(); hlayout->addWidget(&m_slider); hlayout->addWidget(&m_value,0,Qt::AlignRight); QVBoxLayout* vlayout = new QVBoxLayout(); vlayout->addWidget(&m_bar); vlayout->addLayout(hlayout); setLayout(vlayout); connect(&m_slider,SIGNAL(valueChanged ( int)),&m_bar,SLOT(setValue (int))); connect(&m_bar,SIGNAL(valueChanged ( int)),this,SLOT(onvalueChanged (int))); onvalueChanged(m_bar.value()); } void ProgressBar::onvalueChanged(int value) { QString qss= "QProgressBar{"
               "border: 1px solid rgb(16, 135, 209);"
               "background: rgba(248,248,255,180);"
               "border-radius: 6px; }"
               "QProgressBar::chunk:enabled {"
               "border-radius: 4px; "
               "background: qlineargradient(x1:0, y1:0, x2:1, y2:0" ; double v = m_bar.maximum(); double EndColor=static_cast<double>(value)/v ;    //获取比例

    for(int i=0;i<100;i++) { double Current = EndColor*i/100; QRgb rgb = m_image.pixel((m_image.width()-1)*Current,m_image.height()/2); QColor c(rgb); qss.append(QString(",stop:%1 rgb(%2,%3,%4)").arg(i/100.0).arg(c.red()).arg(c.green()).arg(c.blue())); } qss.append(");}"); m_bar.setStyleSheet(qss); m_value.setText(QString("%1%").arg(m_bar.value())); }