网上关于Qcustomplot的应用非常多，但是大多数讲的都不好，尤其是讲到串口+波形时大多数都是应用一个随机函数产生随机数，可移植性非常差，于是我重新写了一下关于Qcustomplot接收串口函数并实时显示波形，波形可随时间移动。先上代码，具体解析见后面：
QString str1 ="FE 04 00 00 00 02 65 C4";
QByteArray senddata;
StringToHex(str1,senddata);//将str字符串转换为16进制的形式
serial->write(senddata);
serial->waitForReadyRead(1);
QByteArray temp = serial->readAll();
// QDataStream out(&temp1,QIODevice::ReadWrite); //将字节数组读入
QString data1=temp.toHex();
QString data2=data1.mid(10,4);//字符串
int t =data2.toInt(0,16) ;//转化成int(不带小数点)
double ts=(double)t/100;
double F =((double)t/100.0)*1.8+32.0;
QString str = QString::number(ts,'f',2);
QString strF = QString::number(F,'f',2);
QDateTime current_date_time =QDateTime::currentDateTime();
QString current_date =current_date_time.toString("hh:mm:ss");
serial->waitForBytesWritten(1);
/*写入曲线图*/
static int graph_count = 0;
static unsigned long count = 0;
static unsigned long count1 = 0;
QString data3=temp.toHex();
QString data4=data3.mid(10,4);//字符串
int num1 =data4.toInt(0,16) ;//转化成int(不带小数点)
double num;
num=(double) num1/100;
if(temp.isEmpty() != true)
{
ui->curveShowWidget->xAxis->setTickStep(3);
graph_count = ui->curveShowWidget->graphCount();
ui->curveShowWidget->addGraph();
ui->curveShowWidget->graph(0)->setPen(QColor(0,0,0,0));
ui->curveShowWidget->addGraph();
ui->curveShowWidget->graph(1)->setPen(QPen(Qt::red,2));
ui->curveShowWidget->graph(1)->addData(ui->doubleSpinBox_3->value()*count++,num*1.8+32.0);
ui->curveShowWidget->addGraph();
if(ui->checkBox->isChecked()==true)
{
ui->curveShowWidget->yAxis->setRange(num-ui->doubleSpinBox->value(),num+ui->doubleSpinBox_2->value());
ui->curveShowWidget->graph(1)->setPen(QColor(0,0,0,0));
ui->curveShowWidget->graph(2)->setPen(QPen(Qt::blue,2));
}
else if(ui->checkBox->isChecked()!=true)
{
ui->curveShowWidget->yAxis->setRange(num*1.8+32-ui->doubleSpinBox->value(),num*1.8+32+ui->doubleSpinBox_2->value());
ui->curveShowWidget->graph(2)->setPen(QColor(0,0,0,0));
ui->curveShowWidget->graph(1)->setPen(QPen(Qt::red,2));
}
ui->curveShowWidget->yAxis->setTickStep(ui->doubleSpinBox_4->value());
ui->curveShowWidget->graph(2)->addData(ui->doubleSpinBox_3->value()*count1++,num);
ui->curveShowWidget->graph(2)->visible()==0;
curveZoom_flag =1;
if(curveZoom_flag == 1)//打开 自动缩放
{
ui->curveShowWidget->graph(1)->rescaleKeyAxis(true);
ui->curveShowWidget->graph(2)->rescaleKeyAxis(true);
}
ui->curveShowWidget->replot();
QApplication::processEvents();
}
else
{
temp=0;
ui->curveShowWidget->addGraph();
ui->curveShowWidget->graph(0)->setPen(QColor(0,0,0,0));
ui->curveShowWidget->addGraph();
ui->curveShowWidget->graph(1)->setPen(QPen(Qt::red,2));
ui->curveShowWidget->graph(1)->addData(ui->doubleSpinBox_3->value()*count++,num*1.8+32.0);
ui->curveShowWidget->addGraph();
}首先本代码通过串口发送一串16进制数 QString str1 =“FE 04 00 00 00 02 65 C4”;该数据发送之后，QByteArray temp = serial->readAll();工控机会返回数据temp，返回的数据中有波形图所需要的信息，所以需要解析,经过一系列解析之后，得到波形数据 num，然后按照下面的程序，即可完成波形的显示。