Qt浅谈之三十九圆形进度条

一、简介

        Qt下进度条一般都是水平或垂直的，有时需要一个椭圆或圆来动态显示进度，或用此来显示存储百分比，都是比较适用的。

二、详解

1、代码

（1）widgetdisplay.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QtCore>
#include <QtGui>

class StorageDisplay : public QWidget
{
Q_OBJECT
public:
StorageDisplay(QWidget *parent = 0);
~StorageDisplay();
void setUsedValue(int value);
//void setSize(int width, int height);
protected:
void paintEvent(QPaintEvent *event);
void resizeEvent (QResizeEvent * event);
void mousePressEvent(QMouseEvent *event);
void mouseMoveEvent(QMouseEvent *event);
void mouseReleaseEvent(QMouseEvent *event);
void showEvent(QShowEvent *event);
void hideEvent(QHideEvent *event);

private slots:
void slotUpdateTimer();

private:
QPoint beginDrag;
bool bPressFlag;

QPixmap backGround;
int userdVaule;
int currentValue;
QLabel *startValueLabel;
QLabel *endValueLabel;
QLabel *dispayValueLabel;

QTimer *updateTimer;
};

#endif // WIDGET_H

（2）widgetdisplay.cpp

#include "widgetdisplay.h"

StorageDisplay::StorageDisplay(QWidget *parent)
: QWidget(parent, Qt::FramelessWindowHint)
, bPressFlag(false)
, currentValue(0)
{
QTextCodec *codec = QTextCodec::codecForName("utf8");
QTextCodec::setCodecForLocale(codec);
QTextCodec::setCodecForCStrings(codec);
QTextCodec::setCodecForTr(codec);
resize(167, 167);
setAutoFillBackground(false);
QPalette pal = palette();
pal.setColor(QPalette::Background, QColor(0xFF,0xFF,0xFF,0xFF));
setPalette(pal);

startValueLabel = new QLabel(tr("0%"), this);
startValueLabel->setFont(QFont("Arial", 11, QFont::Normal));
startValueLabel->setStyleSheet("color:#898989");

endValueLabel = new QLabel(tr("100%"),this);
endValueLabel->setFont(QFont("Arial", 11, QFont::Normal));
endValueLabel->setStyleSheet("color:#898989");

dispayValueLabel = new QLabel(this);
dispayValueLabel->setStyleSheet("color:#349BDA");

updateTimer = new QTimer(this);
updateTimer->setInterval(20);
connect(updateTimer, SIGNAL(timeout()), this, SLOT(slotUpdateTimer()));
}

StorageDisplay::~StorageDisplay()
{
if (updateTimer->isActive()) {
updateTimer->stop();
}
currentValue = 0;
}

void StorageDisplay::setUsedValue(int value)
{
userdVaule = value;
}

void StorageDisplay::showEvent(QShowEvent *event)
{
updateTimer->start();
currentValue = 0;
}

void StorageDisplay::hideEvent(QHideEvent *event)
{
if (updateTimer->isActive()) {
updateTimer->stop();
}
currentValue = 0;
}

void StorageDisplay::slotUpdateTimer()
{
if (currentValue >= userdVaule) {
updateTimer->stop();
return;
}
currentValue++;
update();
}

void StorageDisplay::paintEvent(QPaintEvent *event)
{

QPainter painter(this);
QColor usedColor(165, 220, 62);
QColor freeColor(215, 215, 215);
painter.drawPixmap(QRect((width() - backGround.width())/2 , (height() - backGround.height())/2, backGround.width(), backGround.height()) , backGround);

painter.translate(width() / 2, height() / 2);
painter.setRenderHint(QPainter::Antialiasing);
painter.setRenderHint(QPainter::SmoothPixmapTransform);
painter.save();
painter.rotate(42);
painter.setPen(QPen(usedColor, 2));
for (int i = 0; i < currentValue ; ++i) {
painter.drawLine(0, 70, 0, 80);
painter.rotate(2.8);
}
painter.setPen(QPen(freeColor, 3));
for (int i = currentValue; i < 100 ; ++i) {
painter.drawLine(0, 70, 0, 80);
painter.rotate(2.8);
}
if (currentValue == 0) {
dispayValueLabel->setFont(QFont("Arial", 12, QFont::Bold));
dispayValueLabel->setText(tr("unconfig"));
}
else {
dispayValueLabel->setFont(QFont("Arial", 15, QFont::Bold));
dispayValueLabel->setText(tr("%1%").arg(currentValue));
}
QFontMetrics metrics(dispayValueLabel->font());
int textwidth = metrics.width(dispayValueLabel->text());
int textheight = metrics.height();
dispayValueLabel->setGeometry((width() - textwidth)/2, (height() - textheight)/2 , textwidth, textheight);
painter.restore();

painter.translate(-width()/2, -height()/2);
painter.setBrush(QColor(233, 233, 233));
painter.setPen(QPen(QColor(233, 233, 233), 15));
painter.drawEllipse(QRectF((width()/2 - 55), (height()/2 - 55), 110, 110));

QConicalGradient conicalGradient(width()/2, height()/2, 90);
conicalGradient.setColorAt(0, QColor(45, 204, 112));
conicalGradient.setColorAt(1.0, QColor(51, 152, 219));
painter.setPen(QPen(QBrush(conicalGradient), 30));
painter.drawEllipse(QRectF((width()/2 - 35), (height()/2 - 35), 70, 70));

painter.setPen(Qt::NoPen);
painter.setBrush(QColor(249, 249, 249));
painter.drawEllipse(QRectF((width()/2 - 30), (height()/2 - 30), 60, 60));
}

void StorageDisplay::resizeEvent(QResizeEvent *event)
{
move((QApplication::desktop()->width() - width())/2,  (QApplication::desktop()->height() - height())/2);
startValueLabel->setGeometry(35, 140, 25, 20);
endValueLabel->setGeometry(97, 140, 50, 20);
}

/****************move everywhere*******************/
void StorageDisplay::mousePressEvent(QMouseEvent *event)
{
bPressFlag = true;
beginDrag = event->pos();
QWidget::mousePressEvent(event);
}

void StorageDisplay::mouseMoveEvent(QMouseEvent *event)
{
if (bPressFlag) {
QPoint relaPos(QCursor::pos() - beginDrag);
move(relaPos);
}
QWidget::mouseMoveEvent(event);
}

void StorageDisplay::mouseReleaseEvent(QMouseEvent *event)
{
bPressFlag = false;
QWidget::mouseReleaseEvent(event);
}

</pre><pre>

（3）main.cpp

#include "widgetdisplay.h"
#include <QApplication>

int main(int argc, char *argv[])
{
QApplication a(argc, argv);
StorageDisplay w;
w.setUsedValue(100);
w.show();

return a.exec();
}

（4）编译运行

三、总结

（1）若有问题或建议，请留言，在此感谢！