QCustomplot使用分享(二) 源码解读

 1 customPlot->legend->setVisible(true);
 2  
 3 // 生成2种随机的蜡烛图数据，第一个是蜡烛图数据，第二个是美国线数据
 4 int n = 500;
 5 QVector<double> time(n), value1(n), value2(n);
 6 QDateTime start = QDateTime(QDate(2014, 6, 11));
 7 start.setTimeSpec(Qt::UTC);
 8 double startTime = start.toTime_t();
 9 double binSize = 3600*24; // 1天的数据
10 time[0] = startTime;
11 value1[0] = 60;
12 value2[0] = 20;
13 qsrand(9);//生成随机数时给指定的种子，那么生成的随机数都是相同的，因此每次运行后得到的结果都是不变的
14 for (int i=1; i<n; ++i)
15 {
16   time[i] = startTime + 3600*i;
17   value1[i] = value1[i-1] + (qrand()/(double)RAND_MAX-0.5)*10;
18   value2[i] = value2[i-1] + (qrand()/(double)RAND_MAX-0.5)*3;
19 }
20  
21 // 初始化一个蜡烛图指针:
22 QCPFinancial *candlesticks = new QCPFinancial(customPlot->xAxis, customPlot->yAxis);
23 candlesticks->setName("Candlestick");
24 candlesticks->setChartStyle(QCPFinancial::csCandlestick);//设置图表类型为蜡烛图
25 candlesticks->data()->set(QCPFinancial::timeSeriesToOhlc(time, value1, binSize, startTime));//设置数据
26 candlesticks->setWidth(binSize*0.9);//设置每一个数据项的绘制宽度
27 candlesticks->setTwoColored(true);//设置是否显示两种颜色
28 candlesticks->setBrushPositive(QColor(245, 245, 245));//设置收>开画刷
29 candlesticks->setBrushNegative(QColor(40, 40, 40));//设置收<开画刷
30 candlesticks->setPenPositive(QPen(QColor(0, 0, 0)));//设置收>开画笔
31 candlesticks->setPenNegative(QPen(QColor(0, 0, 0)));//设置收>开画笔
32  
33 // 初始化一个美国线图指针:
34 QCPFinancial *ohlc = new QCPFinancial(customPlot->xAxis, customPlot->yAxis);
35 ohlc->setName("OHLC");
36 ohlc->setChartStyle(QCPFinancial::csOhlc);//设置图表类型为美国线
37 ohlc->data()->set(QCPFinancial::timeSeriesToOhlc(time, value2, binSize/3.0, startTime)); //为了区分于蜡烛图显示，
38 ohlc->setWidth(binSize*0.2);
39 ohlc->setTwoColored(true);
40  
41 // 创建一个坐标轴矩形
42 QCPAxisRect *volumeAxisRect = new QCPAxisRect(customPlot);
43 customPlot->plotLayout()->addElement(1, 0, volumeAxisRect);
44 volumeAxisRect->setMaximumSize(QSize(QWIDGETSIZE_MAX, 100));
45 volumeAxisRect->axis(QCPAxis::atBottom)->setLayer("axes");
46 volumeAxisRect->axis(QCPAxis::atBottom)->grid()->setLayer("grid");
47 // 设置自己构造的坐标轴矩形属性
48 customPlot->plotLayout()->setRowSpacing(0);
49 volumeAxisRect->setAutoMargins(QCP::msLeft|QCP::msRight|QCP::msBottom);
50 volumeAxisRect->setMargins(QMargins(0, 0, 0, 0));
51 // 生成两种颜色的柱状图
52 customPlot->setAutoAddPlottableToLegend(false);//是否自动生成图例
53 QCPBars *volumePos = new QCPBars(volumeAxisRect->axis(QCPAxis::atBottom), volumeAxisRect->axis(QCPAxis::atLeft));
54 QCPBars *volumeNeg = new QCPBars(volumeAxisRect->axis(QCPAxis::atBottom), volumeAxisRect->axis(QCPAxis::atLeft));
55 for (int i=0; i<n/5; ++i)
56 {
57   int v = qrand()%20000+qrand()%20000+qrand()%20000-10000*3;
58   (v < 0 ? volumeNeg : volumePos)->addData(startTime+3600*5.0*i, qAbs(v)); //构造随机数据
59 }
60 volumePos->setWidth(3600*4);
61 volumePos->setPen(Qt::NoPen);
62 volumePos->setBrush(QColor(100, 180, 110));
63 volumeNeg->setWidth(3600*4);
64 volumeNeg->setPen(Qt::NoPen);
65 volumeNeg->setBrush(QColor(180, 90, 90));
66  
67 // 设置自己构造的坐标轴矩形的x轴和QCustomPlot中的坐标轴矩形(默认的会生成一个)x轴同步，两个坐标轴永远显示的坐标范围是一样的
68 connect(customPlot->xAxis, SIGNAL(rangeChanged(QCPRange)), volumeAxisRect->axis(QCPAxis::atBottom), SLOT(setRange(QCPRange)));
69 connect(volumeAxisRect->axis(QCPAxis::atBottom), SIGNAL(rangeChanged(QCPRange)), customPlot->xAxis, SLOT(setRange(QCPRange)));
70 // 构造一个新的坐标轴刻度计算类
71 QSharedPointer<QCPAxisTickerDateTime> dateTimeTicker(new QCPAxisTickerDateTime);
72 dateTimeTicker->setDateTimeSpec(Qt::UTC);
73 dateTimeTicker->setDateTimeFormat("dd. MMMM");
74 volumeAxisRect->axis(QCPAxis::atBottom)->setTicker(dateTimeTicker);//赋予自己构造的坐标轴矩形的x轴一个新的刻度计算类
75 volumeAxisRect->axis(QCPAxis::atBottom)->setTickLabelRotation(15);
76 customPlot->xAxis->setBasePen(Qt::NoPen);
77 customPlot->xAxis->setTickLabels(false);//不显示坐标轴文本
78 customPlot->xAxis->setTicks(false); //  不显示坐标轴  (这个接口实现的不友好，后续文章我会具体说到)
79 customPlot->xAxis->setTicker(dateTimeTicker);//赋予默认的坐标轴矩形的x轴一个新的刻度计算类
80 customPlot->rescaleAxes();
81 customPlot->xAxis->scaleRange(1.025, customPlot->xAxis->range().center());
82 customPlot->yAxis->scaleRange(1.1, customPlot->yAxis->range().center());
83  
84 // 设置两个坐标轴矩形左右对齐
85 QCPMarginGroup *group = new QCPMarginGroup(customPlot);
86 customPlot->axisRect()->setMarginGroup(QCP::msLeft|QCP::msRight, group);
87 volumeAxisRect->setMarginGroup(QCP::msLeft|QCP::msRight, group);