1、概述
源码放在文章末尾
该项目实现了各种曲线的绘制，下面是项目的demo演示：
项目部分代码如下：
#include "frmsmoothcurve.h"
#include "ui_frmsmoothcurve.h"
#include "smoothcurve.h"
#include "qpainter.h"
#include "qdatetime.h"
#include "qdebug.h"#define TIMEMS QTime::currentTime().toString("hh:mm:ss zzz")frmSmoothCurve::frmSmoothCurve(QWidget *parent) : QWidget(parent), ui(new Ui::frmSmoothCurve)
{ui->setupUi(this);//初始化随机数种子srand(QDateTime::currentDateTime().toMSecsSinceEpoch());//随机生成曲线上的点int x = -300;while (x < 300) {datas << QPointF(x, rand() % 300 - 100);x += qMin(rand() % 30 + 5, 300);}//正常曲线pathNormal.moveTo(datas.at(0));for (int i = 1; i < datas.size(); ++i) {pathNormal.lineTo(datas.at(i));}//平滑曲线1//qDebug() << TIMEMS << "createSmoothCurve start";pathSmooth1 = SmoothCurve::createSmoothCurve(datas);//qDebug() << TIMEMS << "createSmoothCurve stop";//平滑曲线2//qDebug() << TIMEMS << "createSmoothCurve2 start";pathSmooth2 = SmoothCurve::createSmoothCurve2(datas);//qDebug() << TIMEMS << "createSmoothCurve2 stop";ui->ckShowPoint->setChecked(true);connect(ui->ckShowPoint, SIGNAL(clicked(bool)), this, SLOT(update()));connect(ui->rbtnPathNormal, SIGNAL(clicked(bool)), this, SLOT(update()));connect(ui->rbtnPathSmooth1, SIGNAL(clicked(bool)), this, SLOT(update()));connect(ui->rbtnPathSmooth2, SIGNAL(clicked(bool)), this, SLOT(update()));
}frmSmoothCurve::~frmSmoothCurve()
{delete ui;
}void frmSmoothCurve::paintEvent(QPaintEvent *)
{QPainter painter(this);painter.setRenderHint(QPainter::Antialiasing);painter.translate(width() / 2, height() / 2);painter.scale(1, -1);//画坐标轴painter.setPen(QColor(180, 180, 180));painter.drawLine(-250, 0, 250, 0);painter.drawLine(0, 150, 0, -150);//根据选择绘制不同的曲线路径painter.setPen(QPen(QColor(80, 80, 80), 2));if (ui->rbtnPathSmooth1->isChecked()) {painter.drawPath(pathSmooth1);} else if (ui->rbtnPathSmooth2->isChecked()) {painter.drawPath(pathSmooth2);} else {painter.drawPath(pathNormal);}//如果曲线上的点可见则显示出来if (ui->ckShowPoint->isChecked()) {painter.setPen(Qt::black);painter.setBrush(Qt::gray);foreach (QPointF point, datas) {painter.drawEllipse(point, 3, 3);}}
}
