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！