qt折线图显示数据

                     前面也写了一个关于折线的，可是那个太...，暑假没事在家又弄了一个，希望它能够有一点可适应性和扩展性。

                    

                    下面是代码实现

     

/*************************************************折线图绘制author 周翔2012-8-14*************************************************/#ifndef LINEGRAPHWIDGET_H#define LINEGRAPHWIDGET_H#include <QWidget>#include <QPen>#include <QPainter>#include <QResizeEvent>//#include <QDebug>#include <QTimer>struct point{int x;int y;};class LineGraphWidget : public QWidget{Q_OBJECTpublic://mix和max为折线的y轴的数据范围explicit LineGraphWidget(int mix, int max,QWidget *parent = 0);void setSingleUnitX(const int &value) {singleUnitX = value;}//设置x轴的一个单位占多少个像素，默认10//支持定时器定时更新void startUpdataTimer(int msecond);void stopUpdataTimer();signals://支持实时更新void newDataCome();//有新数据到来时发出的折线图更新信号public slots:void showData(const int &data);//接受来之外部的数据protected:void paintEvent(QPaintEvent *);void resizeEvent(QResizeEvent *e);private:QList<int> xList;QList<int> yList;int Counter;//窗口的长和宽int widgetX;int widgetY;//折线图的显示范围int rangeMin;int rangeMax;//根据窗口和范围得出的单位长，x轴,y轴int singleUnitX;int singleUnitY;//根据窗口得出的多少个单位,x轴,y轴int sumUnitX;int sumUnitY;point basePoint;//折线图的原点point xAxisEndPoint;//X轴的终点point yAxisEndPoint;//Y轴的终点QTimer *timer;void getSumUnitX();void getSingleUnitY();void initGraph();};#endif // LINEGRAPHWIDGET_H#include "linegraphwidget.h"LineGraphWidget::LineGraphWidget(int mix, int max, QWidget *parent) :QWidget(parent),rangeMin(mix),rangeMax(max),singleUnitX(10),timer(NULL){connect(this,SIGNAL(newDataCome()),this,SLOT(update()));}void LineGraphWidget::paintEvent(QPaintEvent *){int i;int a,b,c,d;Counter = 0;QPixmap pix(widgetX,widgetY);QPainter painter(&pix);pix.fill(Qt::white);QPen pen;pen.setBrush(Qt::darkGreen);painter.setPen(pen);QPen pen1;pen1.setBrush(Qt::black);painter.setRenderHint(QPainter::Antialiasing);for(i = 0;i < sumUnitX; ++i) {a = basePoint.x + i*singleUnitX;b = basePoint.y;c= a;d = yAxisEndPoint.y;painter.drawLine(a,b,c,d);}for(i = 0; i < sumUnitY+1; ++i) {a = basePoint.x;b = basePoint.y - singleUnitY*i;c = xAxisEndPoint.x;d = b;painter.drawLine(a,b,c,d);}painter.setPen(pen1);for (i = 0;i < (sumUnitY/2+1);++i) {QRectF rectF(0,basePoint.y - singleUnitY*i*2 - 5,basePoint.x,(widgetY - basePoint.y)/3);painter.drawText(rectF,Qt::AlignCenter,QString::number(rangeMin+i*20));}for (i = 0;i < sumUnitX/5;++i) {QRectF rectF(basePoint.x+singleUnitX*(5*i+3),basePoint.y,singleUnitX*4,widgetY-basePoint.y);painter.drawText(rectF,Qt::AlignCenter,QString::number(5*(i+1)*singleUnitX));}int size = xList.size();while(Counter < (size -1)) {painter.drawLine(basePoint.x + xList.value(Counter)*singleUnitX,basePoint.y - ((yList.value(Counter) - rangeMin)/10.0)*singleUnitY,basePoint.x + xList.value(Counter + 1)*singleUnitX,basePoint.y - ((yList.value(Counter + 1) - rangeMin)/10.0)*singleUnitY);Counter++;}painter.end();painter.begin(this);painter.drawPixmap(0,0,pix);painter.end();Counter = 0;}void LineGraphWidget::resizeEvent(QResizeEvent * e){if (e->oldSize() != size()) {initGraph();}}void LineGraphWidget::showData(const int &data){//这里还要进行相关的数据正确性检测，不能超过图的范围if (data > rangeMax || data < rangeMin) {return;}int xsize = xList.size();int yValue = data;if (xsize == sumUnitX) {xList.clear();yList.clear();xsize = xList.length();}if (xsize >= 1) {xList.insert(xsize,xsize);yList.insert(xsize,yValue);emit newDataCome();}else {xList.insert(xsize,xsize);yList.insert(xsize,yValue);}}void LineGraphWidget::getSumUnitX(){if ((static_cast<int>(widgetX*0.85))%singleUnitX == 0){sumUnitX = (static_cast<int>(widgetX*0.85))/singleUnitX;}else {sumUnitX = (static_cast<int>(widgetX*0.85))/singleUnitX + 1;}}void LineGraphWidget::getSingleUnitY(){int range = rangeMax - rangeMin;if (range == 0) {sumUnitY = range/10 + 1;}else {sumUnitY = range/10 + 2;}singleUnitY = (static_cast<int>(widgetY*0.85))/sumUnitY;}void LineGraphWidget::initGraph(){widgetX = size().width();widgetY = size().height();basePoint.x = static_cast<int>(widgetX*0.1);basePoint.y = static_cast<int>(widgetY*0.9);yAxisEndPoint.x = basePoint.x;yAxisEndPoint.y = static_cast<int>(widgetY*0.05);xAxisEndPoint.x = static_cast<int>(widgetX*0.95);xAxisEndPoint.y = basePoint.y;getSumUnitX();getSingleUnitY();}void LineGraphWidget::startUpdataTimer(int msecond){if (timer != NULL) {if (timer->isActive()) {timer->stop();}delete timer;}disconnect(SIGNAL(newDataCome()));timer = new QTimer;connect(timer,SIGNAL(timeout()),this,SLOT(update()));timer->start(msecond);}void LineGraphWidget::stopUpdataTimer(){if (timer == NULL) {}else {timer->stop();delete timer;}}

这篇博客还是去年暑假写的，下面几位仁兄，纠结与main函数怎么写，我很是....，我认为这不是问题。

还是我把代码注释一下吧

/*************************************************  折线图绘制  author 周翔  2012-8-14  对外提供接口   void showData(int data);接受外部的折线数据   void setSingleUnitX(const int &value);设置x轴的单位像素   void startUpdataTimer(int msecond);定时器更新折线图   void stopUpdataTimer();关闭定时器  *************************************************/#ifndef LINEGRAPHWIDGET_H#define LINEGRAPHWIDGET_H#include <QWidget>#include <QPen>#include <QPainter>#include <QResizeEvent>//#include <QDebug>#include <QTimer>struct point{    int x;    int y;};class LineGraphWidget : public QWidget{    Q_OBJECTpublic:    //mix和max为折线的y轴的数据范围    explicit LineGraphWidget(int min, int max, QWidget *parent = 0);    void setSingleUnitX(const int &value) {singleUnitX = value;}//设置x轴的一个单位占多少个像素，默认10    //支持定时器定时更新    void startUpdataTimer(int msecond);    void stopUpdataTimer();signals:    //支持实时更新    void newDataCome();//有新数据到来时发出的折线图更新信号public slots:    /**     * @brief showData     * @param adress 地址     * @param _data 数据     */    void showData(const QString& adress,int _data);//接受来之外部的数据    /**     * @brief slt_showData 接受外部数据     * @param name 设备名     * @param _data 数据     */    void slt_showData(ushort name,int _data);protected:    void paintEvent(QPaintEvent *);    void resizeEvent(QResizeEvent *e);private:    QString  m_currentNodeAdress;//当前显示的节点的地址    ushort m_currentNodeName;//当前节点的设备名    QList<int> xList;    QList<int> yList;    int Counter;    //窗口的长和宽    int widgetX;    int widgetY;    //折线图的显示范围    int rangeMin;    int rangeMax;    //根据窗口和范围得出的单位长，x轴,y轴    int singleUnitX;    int singleUnitY;    //根据窗口得出的多少个单位,x轴,y轴    int sumUnitX;    int sumUnitY;    point basePoint;//折线图的原点    point xAxisEndPoint;//X轴的终点    point yAxisEndPoint;//Y轴的终点    QTimer *timer;    void getSumUnitX();    void getSingleUnitY();    void initGraph();    void flush();//数据传入的节点不是现在的当前的节点的时候，刷新画面，清除所有的值};#endif // LINEGRAPHWIDGET_H