使用QT动态绘制动态曲线

#include "drawer.h" #include <QPalette> #include <QPainter> #include <QtGui> #include<QColor> #include<iostream> Drawer::Drawer(QWidget *parent) : QWidget(parent) { myTimerId=0; xpos=0; pixel=-10; //负数证明向左移动 displayDatacharge=0; displayDatalypos=0; } void Drawer::openDraw() { Close=false; myTimerId=startTimer(100);//第一个时钟，返回1 } void Drawer::closeDraw() { Close=true; killTimer(myTimerId); update(); } void Drawer::drawGrid(QPainter &painter)//绘制网格 { painter.setPen(Qt::red); //定时绘制竖直方向的直线 //if(this->xpos==0||xpos%2==0) // painter.drawLine(this->width()-0.5,-this->height(),this->width()-0.5,0); xpos++; //绘制水平方向的直线 for(int u=0;u<this->height();u++) { if(u%20==0) { painter.drawLine(0,-u,this->width(),-u); } } //绘制水平方向的直线 for(int t=0;t<this->width();t++) { if(t%20==0) { painter.drawLine(t,0,t,-this->height()); } } } void Drawer::drawCurves(QPainter &painter)//绘制实时曲线 { painter.setPen(Qt::green); displayDatafypos=displayDatacharge; displayDatacharge=displayDatalypos; painter.drawLine(this->width()+this->pixel,-displayDatafypos,this->width(),-displayDatalypos); } void Drawer::paintEvent(QPaintEvent *) { QPainter paint(this); paint.setBrush(Qt::white);//设置绘制背景的笔的颜色 paint.setViewport(0,0,this->width(),this->height());//设置视口，物理坐标 paint.setWindow(QRect(0,-this->height(),this->width(),this->height()));//设置窗口，逻辑坐标 paint.drawRect(0,-this->height(),this->width(),this->height());//绘制背景 if(Close!=true) { drawGrid(paint); drawCurves(paint); } } void Drawer::timerEvent(QTimerEvent *event) //当时钟周期定义是启动 { if(event->timerId()==myTimerId){ scroll(this->pixel,0); displayDatalypos=rand()%150; //数据的入口; } else{ QWidget::timerEvent(event);} }