1 void MainWindow::readcsvfile() //讀取csv
 2 {
 3  QFile csvFile("C:/Users/Administrator/Desktop/Demo/0702.CSV");
 4  QStringList csvList;
 5  csvList.clear();
 6  if (csvFile.open(QIODevice::ReadWrite)) //對csv檔案進行讀寫操作
 7  {
 8   QTextStream stream(&csvFile);
 9   while (!stream.atEnd())
10  {
11  csvList.push_back(stream.readLine()); //
 
儲存到List當中
12  }
13  csvFile.close();
14  }
15  else
16  {
17      QMessageBox::about(NULL, "csv檔案", "未開啟該檔案！");
18  }
19    int i = 0;
20    Q_FOREACH(QString str, csvList)   //遍歷List
21   {
22    i = i + 1;
23    QStringList valsplit = str.split(","); //分隔字串
24    if(i > 2)
25    {
26     //得到深度、聲速、溫度
27
 
     QString depth = valsplit[0];
28     QString sonicvelocity = valsplit[1];
29     QString temperature = valsplit[2];
30     double depthvalue = depth.toDouble();
31     double sonicvalue = sonicvelocity.toDouble();
32     double tempvalue = temperature.toDouble();
33     //Q//MessageBox::warning(NULL, "dd", QString::number(tempvalue));
 

34     QPointF point;
35     point.setX(depthvalue);
36     point.setY(sonicvalue);
37     QPointF point2;
38     point2.setX(depthvalue);
39     point2.setY(tempvalue + 1510);
40     vectors.append(point);
41     vector2.append(point2);
42    }
43   }
44 }
45  
46 void MainWindow::lineChart() //繪製圖
47 {
48     //設定X,Y標題
49     ui->qwtPlot->setAxisTitle(QwtPlot::xBottom, QString::fromLocal8Bit("深度(m)"));
50     ui->qwtPlot->setAxisTitle(QwtPlot::yLeft, QString::fromLocal8Bit("聲速(m/s)"));
51     ui->qwtPlot->setAxisTitle(QwtPlot::yRight, QString::fromLocal8Bit("溫度(°C)"));
52     ui->qwtPlot->enableAxis(QwtPlot::yRight,true);
53     ui->qwtPlot->setAxisScale(QwtPlot::yLeft,1538,1540,0.2);
54     ui->qwtPlot->setAxisScale(QwtPlot::xBottom,0,30,2);
55     ui->qwtPlot->setAxisScale(QwtPlot::yRight,28,30,0.2);
56  
57     //ui->qwtPlot->set
58     //構造麴線資料
59      QwtPointSeriesData* series = new QwtPointSeriesData(vectors);
60      //設定網格
61      QwtPlotGrid* grid = new QwtPlotGrid();
62      grid->setPen(QColor(222, 222, 222), 1);
63      grid->attach(ui->qwtPlot);
64      //create plot item
65      QwtPlotCurve* curve1 = new QwtPlotCurve(QString::fromLocal8Bit("聲速"));
66      //設定資料
67      curve1->setData(series);
68      //設定畫筆顏色==就是影象顏色
69      curve1->setPen(QColor(255, 0, 0), 2, Qt::SolidLine);
70      //使曲線更光滑
71      curve1->setCurveAttribute(QwtPlotCurve::Fitted, true);
72      //把曲線附加到qwtPlot上
73      curve1->attach(ui->qwtPlot);
74      //新增溫度-深度曲線
75      //構造麴線資料
76      QwtPointSeriesData* series2 = new QwtPointSeriesData(vector2);
77      //create plot item
78      QwtPlotCurve* curve2 = new QwtPlotCurve(QString::fromLocal8Bit("溫度"));
79      //設定資料
80      curve2->setData(series2);
81      //設定畫筆顏色=影象顏色
82      curve2->setPen(QColor(127, 222, 335), 2, Qt::SolidLine);
83      //使曲線更光滑
84      curve2->setCurveAttribute(QwtPlotCurve::Fitted, true);
85      //把曲線附加到qwtPlot上
86      curve2->attach(ui->qwtPlot);
87  
88      //設定圖例
89      QwtLegend *legend = new QwtLegend;
90      legend->setDefaultItemMode(QwtLegendData::ReadOnly);
91      ui->qwtPlot->insertLegend(legend,QwtPlot::BottomLegend);//插入圖例
92      ui->qwtPlot->replot();
93      ui->qwtPlot->show();
94 }

需要第三方庫QWT

執行結果：