求高手简单注释一下这个程序太感激了这个程序貌似是画了一个带指针的表盘 - QTCN开发网

只看楼主倒序阅读楼主发表于: 2011-01-20

#include "dialog.h"
#include "ui_dialog.h"

Dialog::Dialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Dialog)
{
    ui->setupUi(this);
    initVariables();
}

void Dialog::initVariables()                             /*初始化*/
{
    m_outerRadius=width()>height() ? height()/4: width()/4;           /*外径*/
    m_innerRadius=m_outerRadius/8*7;                           /*内径*/
    m_coverCircleRadius=m_outerRadius/8*4+10;
    m_colorCircleRadius=m_outerRadius/8*5;                      /*颜色*/
   // m_center=rect().center();
    m_value=0;
    //m_currentValue=0;
    singleTimer=new QTimer(this);                               /*定时器*/
    connect(singleTimer,SIGNAL(timeout()),this,SLOT(update()));
    singleTimer->start();
}

void Dialog::paintEvent(QPaintEvent *)
{
    QPainter painter(this);
    painter.setRenderHints(QPainter::Antialiasing|QPainter::TextAntialiasing);
       resetVariables(&painter);
       drawMark(&painter);
       drawIndicator(&painter);
       drawCoverBall(&painter);
    painter.end();
}

void Dialog::drawMark(QPainter *painter)
{

   painter->save();
    painter->setPen(Qt::red);
    painter->translate(m_center);

    qreal dAngle=(qreal)0.3;
    qreal startAngle=0;
    int value=0;
    QString strValue;
    for(int i=0;i<=700;i++)        /*表盘上的最大刻度*/
    {
        painter->save();
        painter->rotate(startAngle);

       if(i%100==0)
        {
            strValue=tr("%1").arg(value);
            qreal textWidth=fontMetrics().width(strValue);
            qreal textHeight=fontMetrics().height();
            QPointF bottomPot(0,m_colorCircleRadius+SPACE+OK);
            QPointF topPot(0,m_colorCircleRadius+SPACE-OK);
            painter->drawLine(bottomPot,topPot);
            value+=100;

            painter->save();
            QPointF textPot(0-textWidth/2,m_colorCircleRadius+LONG-textHeight);
            painter->translate(textPot);
            painter->rotate(180);
            painter->drawText(QPointF(-textWidth,textHeight/2),strValue);
            painter->restore();

        }else if(i%20==0)
        {
            QPointF bottomPot(0,m_colorCircleRadius+SPACE);
            QPointF topPot(0,m_colorCircleRadius+SPACE+OK);
            painter->drawLine(bottomPot,topPot);

        }
        painter->restore();

        startAngle+=dAngle;

    }

    painter->restore();
}

void Dialog::drawCoverBall(QPainter *painter)
{
    painter->save();

    qreal ballRadius=m_outerRadius/10;
    m_coverBallRadius=ballRadius;
    QRadialGradient ballGradient(m_center,ballRadius,m_center);
    ballGradient.setColorAt(0.0,QColor(236,187,62));
    ballGradient.setColorAt(0.7,QColor(220,147,0));
    ballGradient.setColorAt(1.0,QColor(236,187,62));
    painter->setBrush(ballGradient);
    painter->setPen(Qt::NoPen);
    painter->drawEllipse(m_center,ballRadius,ballRadius);
    painter->restore();
}
void Dialog::drawIndicator(QPainter *painter)
{
    painter->save();
    int A=2;                     /*指针所指的表盘上最小格的数目，改变此参数，指针就有所变化*/
    painter->translate(m_center);
    qreal increment=(qreal)210/35;
    qreal changedAngle=increment*A;
    painter->rotate(changedAngle);

    QPointF topPot(0,m_colorCircleRadius+LONG);
    QPointF bottomLeftPot(-m_coverBallRadius/3,0);
    QPointF bottomRightPot(m_coverBallRadius/3,0);
    painter->setPen(Qt::NoPen);

    QLinearGradient indicatorGradient(topPot,bottomLeftPot);
    indicatorGradient.setColorAt(0.0,QColor(0,170,255));
    indicatorGradient.setColorAt(0.5,QColor(0,170,255));
    indicatorGradient.setColorAt(1.0,QColor(0,170,255));

    painter->setBrush(indicatorGradient);
    QVector<QPointF> potVec;
    potVec.push_back(topPot);
    potVec.push_back(bottomLeftPot);
    potVec.push_back(bottomRightPot);
    painter->drawPolygon(potVec);

    painter->restore();
}

void Dialog::resetVariables(QPainter *painter)
{
    m_outerRadius=width()>height() ? height()/4: width()/4;
    m_innerRadius=m_outerRadius/8*7;
    m_coverCircleRadius=m_outerRadius/8*4+10;
    m_colorCircleRadius=m_outerRadius/8*5;
    int a=200,b=250;
    painter->translate(a,b);
   // m_center=rect().center();
}

Dialog::~Dialog()
{
    delete ui;
}