Qt利用paintEvent绘制双Y轴坐标折线图

在项目中，根据需求需要开发双Y轴坐标折线图，但是由于它有多个图层，如果使用QChart绘制的话，达不到需求的要求，只能自己绘制，具体的利用translate()接口将坐标系统移动到界面的左下角(30, height() - 50)处，这样向上就是-y，向下+y，数据映射到坐标系上面更加的方便，具体实现如下：

#pragma once
#include 
#include 
#include 
#include 
class DrawBoneArg : public QWidget
{
	Q_OBJECT
public:
	//tuple元素前两个是左Y轴最大最小值，中间两个是右Y轴最大最小值，最后两个是x轴最大最小值，   其他三个参数分别是轴的偏移量(每个间隔多少值)
	explicit DrawBoneArg(std::tuple<double, double, double, double, double, double > AxisMaxMinValue = { 0.58,1.42,-5,2,20,100 }, double leftYAxisOffset = 0.12, double rightYAxisOffset = 1, int xAxisOffset = 5, QWidget* parent = nullptr);

	//从数据库中读出的标准数据
	void setStandardData(std::vector<std::map<unsigned int, double> > standardData);

	//绘制区域的最大最小值(对应的左Y轴值)，颜色，字体
	void setRegionMaxMinColorTextValue(std::vector<std::tuple<double, double, QColor, std::string> > RegionData);

	void setInspectResult(unsigned int age, const double boneValue);

	void setInspectResult(std::vector<std::pair<unsigned int, double> > re);
private:
	void drawBackGround(QPainter& painter);

	void drawAxis(QPainter& painter);

	void drawRegion(QPainter& painter);

	void drawValueLine(QPainter& painter);

	void drawInspectResult(QPainter& painter);

	void initWin();
protected:
	void paintEvent(QPaintEvent* pEvent);

private:

	//坐标轴上刻度跟刻度之间的距离
	float m_yLeftAxisCoefficient;
	float m_yRightAxisCoefficient;
	float m_xAgeAxisCoefficient;

	//绘制折线标准数据第一个是年龄，第二个是标准版骨密度值
	std::vector<std::map<unsigned int, double> > m_boneStandardData;

	//前两个元素左Y轴最小最大值， 中间两个元素右Y轴最小最大值， 最后两个X轴最小最大值
	std::tuple<double, double, double, double, double, double> m_dAxisMaxMinValue;

	std::vector<std::tuple<double, double, QColor, std::string> >  m_regionData;
	
	//x轴偏移量
	int m_iAgeOffset;

	//左Y轴偏移量
	double m_dLeftYAxisOffset;

	//右Y轴偏移量
	double m_dRightYAxisOffset;

	//当前检查者检查结果
	std::vector<std::pair<unsigned int, const double> > m_InspectResult;
};
#include "DrawBoneArg.h"

DrawBoneArg::DrawBoneArg(std::tuple<double, double, double, double, double, double> AxisMaxMinValue, double leftYAxisOffset, double rightYAxisOffset, int xAxisOffset, QWidget* parent)
	: QWidget(parent)
	, m_dAxisMaxMinValue(AxisMaxMinValue)
	, m_iAgeOffset(xAxisOffset)
	, m_dLeftYAxisOffset(leftYAxisOffset)
	, m_dRightYAxisOffset(rightYAxisOffset)
{
	this->initWin();
	
}

void DrawBoneArg::initWin()
{

	std::map<unsigned int, double> map1;
	map1.insert(std::pair<unsigned int, double>(20, 1.06));
	map1.insert(std::pair<unsigned int, double>(25, 1.06));
	map1.insert(std::pair<unsigned int, double>(30, 1.06));
	map1.insert(std::pair<unsigned int, double>(35, 1.06));
	map1.insert(std::pair<unsigned int, double>(40, 1.06));
	map1.insert(std::pair<unsigned int, double>(45, 1.06));
	map1.insert(std::pair<unsigned int, double>(50, 1.03));
	map1.insert(std::pair<unsigned int, double>(55, 0.98));
	map1.insert(std::pair<unsigned int, double>(60, 0.94));
	map1.insert(std::pair<unsigned int, double>(65, 0.93));
	map1.insert(std::pair<unsigned int, double>(70, 0.90));
	map1.insert(std::pair<unsigned int, double>(75, 0.88));
	map1.insert(std::pair<unsigned int, double>(80, 0.86));
	map1.insert(std::pair<unsigned int, double>(85, 0.84));
	map1.insert(std::pair<unsigned int, double>(90, 0.83));
	map1.insert(std::pair<unsigned int, double>(95, 0.82));
	map1.insert(std::pair<unsigned int, double>(100, 0.81));
	this->m_boneStandardData.emplace_back(map1);

	map1.clear();
	map1.insert(std::pair<unsigned int, double>(20, 1.18));
	map1.insert(std::pair<unsigned int, double>(25, 1.18));
	map1.insert(std::pair<unsigned int, double>(30, 1.18));
	map1.insert(std::pair<unsigned int, double>(35, 1.18));
	map1.insert(std::pair<unsigned int, double>(40, 1.18));
	map1.insert(std::pair<unsigned int, double>(45, 1.18));
	map1.insert(std::pair<unsigned int, double>(50, 1.14));
	map1.insert(std::pair<unsigned int, double>(55, 1.11));
	map1.insert(std::pair<unsigned int, double>(60, 1.08));
	map1.insert(std::pair<unsigned int, double>(65, 1.02));
	map1.insert(std::pair<unsigned int, double>(70, 0.98));
	map1.insert(std::pair<unsigned int, double>(75, 0.96));
	map1.insert(std::pair<unsigned int, double>(80, 0.952));
	map1.insert(std::pair<unsigned int, double>(85, 0.947));
	map1.insert(std::pair<unsigned int, double>(90, 0.942));
	map1.insert(std::pair<unsigned int, double>(95, 0.938));
	map1.insert(std::pair<unsigned int, double>(100, 0.935));
	this->m_boneStandardData.emplace_back(map1);

	map1.clear();
	map1.insert(std::pair<unsigned int, double>(20, 1.30));
	map1.insert(std::pair<unsigned int, double>(25, 1.30));
	map1.insert(std::pair<unsigned int, double>(30, 1.30));
	map1.insert(std::pair<unsigned int, double>(35, 1.30));
	map1.insert(std::pair<unsigned int, double>(40, 1.30));
	map1.insert(std::pair<unsigned int, double>(45, 1.30));
	map1.insert(std::pair<unsigned int, double>(50, 1.26));
	map1.insert(std::pair<unsigned int, double>(55, 1.20));
	map1.insert(std::pair<unsigned int, double>(60, 1.17));
	map1.insert(std::pair<unsigned int, double>(65, 1.11));
	map1.insert(std::pair<unsigned int, double>(70, 1.09));
	map1.insert(std::pair<unsigned int, double>(75, 1.08));
	map1.insert(std::pair<unsigned int, double>(80, 1.07));
	map1.insert(std::pair<unsigned int, double>(85, 1.065));
	map1.insert(std::pair<unsigned int, double>(90, 1.06));
	map1.insert(std::pair<unsigned int, double>(95, 1.055));
	map1.insert(std::pair<unsigned int, double>(100, 1.045));
	this->m_boneStandardData.emplace_back(map1);

	std::tuple<double, double, QColor, std::string> tup1(0.58, 0.88, QColor(255,1,0), "红色");
	std::tuple<double, double, QColor, std::string> tup2(0.88, 1.06, QColor(254,255,0), "黄色");
	std::tuple<double, double, QColor, std::string> tup3(1.06, 1.42, QColor(0, 130, 0), "绿色");
	m_regionData.emplace_back(tup1);
	m_regionData.emplace_back(tup2);
	m_regionData.emplace_back(tup3);

	//this->setInspectResult(70, 1.06);

	std::pair<unsigned int, double> pa{ 75, 1.07 };
	std::pair<unsigned int, double> pa1{ 73, 1.12 };
	std::vector<std::pair<unsigned int, double> > vec;
	vec.push_back(pa);
	vec.push_back(pa1);
	setInspectResult(vec);
}

void DrawBoneArg::setStandardData(std::vector<std::map<unsigned int, double> > standardData)
{
	m_boneStandardData = standardData;
	this->update();
}

void DrawBoneArg::setRegionMaxMinColorTextValue(std::vector<std::tuple<double, double, QColor, std::string> > data)
{
	m_regionData = data;
}

void DrawBoneArg::setInspectResult(unsigned int age, const double boneValue)
{
	m_InspectResult.clear();
	std::pair<unsigned int, const double> re = std::make_pair(age, boneValue);
	m_InspectResult.emplace_back(re);
	this->update();
}

void DrawBoneArg::setInspectResult(std::vector<std::pair<unsigned int, double> > re)
{
	if (re.empty())return;
	m_InspectResult.clear();
	auto it = re.begin();
	while (it != re.end())
	{
		m_InspectResult.emplace_back(*it);
		++it;
	}
	this->update();
}

void DrawBoneArg::paintEvent(QPaintEvent* pEvent)
{
	QPainter painter(this);
	painter.setRenderHint(QPainter::Antialiasing, true);
	this->drawBackGround(painter);
	this->drawAxis(painter);
	this->drawRegion(painter);
	this->drawValueLine(painter);
	this->drawInspectResult(painter);
	QWidget::paintEvent(pEvent);
}

void DrawBoneArg::drawBackGround(QPainter& painter)
{
	painter.setPen(Qt::NoPen);
	painter.setBrush(QColor(214,210,207));
	painter.drawRect(rect());
}

void DrawBoneArg::drawAxis(QPainter& painter)
{
	//将坐标系移动到界面左下角(30, this->height()_50)处
	painter.translate(30, this->height() - 50);

	painter.setPen(QPen(Qt::black));
	painter.drawLine(QPointF(0, 0), QPointF(0, -this->height() + 100));//左竖线
	QPointF yRe = QPointF(0, -this->height() + 100) - QPointF(0, 0);

	int leftYNum = (std::get<1>(this->m_dAxisMaxMinValue) - std::get<0>(this->m_dAxisMaxMinValue)) / this->m_dLeftYAxisOffset;
	float coefficient = yRe.y() / leftYNum;
	m_yLeftAxisCoefficient = coefficient;
	float y = 0;
	float v = std::get<0>(m_dAxisMaxMinValue);
	for (int i = 0; i <= leftYNum; i++)
	{
		painter.drawLine(QPointF(0, y), QPointF(-5, y));
		painter.drawText(QPointF(-25, y-2), QString::number(v, 'f', 2));
		v += m_dLeftYAxisOffset;
		y += coefficient;
	}
	QFont font;
	font.setPointSizeF(12);
	painter.drawText(QPointF(-20, -this->height() + 85), "BMD(g/cm2)");//QString::fromUtf8("2\u00B2")
	
	painter.drawLine(QPointF(0, 0), QPointF(this->width() - 60, 0));//底横线
	QPointF re = QPointF(this->width() - 60, 0) - QPointF(0, 0);
	int xAixsNum = (std::get<5>(this->m_dAxisMaxMinValue) - std::get<4>(m_dAxisMaxMinValue)) / this->m_iAgeOffset;
	float coefficientX = re.x() / xAixsNum;
	m_xAgeAxisCoefficient = coefficientX;
	float x = 0;
	int age = std::get<4>(this->m_dAxisMaxMinValue);
	for (int i = 0; i <= xAixsNum; i++)
	{
		painter.drawLine(QPointF(x, 0), QPointF(x, 5));
		if (i % 2 == 0)
			painter.drawText(QPointF(x - 5, 15), QString::number(age));
		x += coefficientX;
		age += m_iAgeOffset;
	}

	font.setPointSizeF(12);
	painter.setFont(font);
	painter.drawText(re.x() / 2 - 25, 30, QStringLiteral("年龄(岁)"));
	font.setPointSize(10);
	painter.setFont(font);
	painter.drawText(re.x() / 2 - 10, 45, QStringLiteral("中国"));

	
	painter.drawLine(QPointF(0, -this->height() + 100), QPointF(this->width() - 60, -this->height() + 100));//上横线
	QPointF xTop = QPointF(this->width() - 60, -this->height() + 100) - QPointF(0, -this->height() + 100);
	float textX = xTop.x() / 2 - 50;
	font.setPointSizeF(15);
	painter.drawText(textX, -this->height() + 85, QStringLiteral("骨密度-脊柱[L1-L4]"));

	
	painter.drawLine(QPointF(this->width() - 60, -this->height() + 100), QPointF(this->width() - 60, 0));//右竖线
	QPointF yRightRe = QPointF(this->width() - 60, -this->height() + 100) - QPointF(this->width() - 60, 0);

	int rightYAxis = (std::get<3>(this->m_dAxisMaxMinValue) - std::get<2>(this->m_dAxisMaxMinValue)) / m_dRightYAxisOffset;
	float coefficientYRight = yRightRe.y() / rightYAxis;
	m_yRightAxisCoefficient = coefficientYRight;
	float yRight = 0;
	float vy = std::get<2>(this->m_dAxisMaxMinValue);
	for (int i = 0; i <= rightYAxis; i++)
	{
		painter.drawLine(QPointF(this->width() - 60, yRight), QPointF(this->width() - 55, yRight));
		painter.drawText(QPointF(this->width() - 52, yRight), QString::number(vy));
		vy += m_dRightYAxisOffset;
		yRight += coefficientYRight;
	}

	font.setPointSizeF(10);
	painter.drawText(QPointF(this->width() - 120, -this->height() + 85), QString("YA T-score"));
}


void DrawBoneArg::drawRegion(QPainter& painter)
{
	QPen pen(Qt::black);
	pen.setWidth(2);
	painter.setPen(pen);
	
	auto it = this->m_regionData.begin();
	while (it != this->m_regionData.end())
	{
		float yAxisValue = ((std::get<1>(*it) - std::get<0>(m_dAxisMaxMinValue)) / m_dLeftYAxisOffset) * m_yLeftAxisCoefficient;
		float height = ((std::get<1>(*it) - std::get<0>(*it)) / m_dLeftYAxisOffset) * m_yLeftAxisCoefficient;
		QBrush brush(std::get<2>(*it));
		painter.setBrush(brush);
		painter.drawRect(0, yAxisValue, this->width() - 60, -height);
		QFont font;
		font.setPointSizeF(12);
		painter.setFont(font);
		painter.drawText(2, yAxisValue - 2, this->width() - 60, -height, Qt::AlignLeft | Qt::AlignBottom, QString::fromLocal8Bit(std::get<3>(*it).c_str()));
		++it;
	}
}



void DrawBoneArg::drawValueLine(QPainter& painter)
{
	QPen pen(Qt::black);
	pen.setWidth(2);
	painter.setPen(pen);
	auto it = this->m_boneStandardData.begin();
	while (it != this->m_boneStandardData.end())
	{
		auto mapIt = it->begin();
		QPolygonF poly;
		while (mapIt != it->end())
		{
			double x = ((mapIt->first - std::get<4>(m_dAxisMaxMinValue)) / m_iAgeOffset) * m_xAgeAxisCoefficient;
			double y = ((mapIt->second - std::get<0>(m_dAxisMaxMinValue)) / m_dLeftYAxisOffset) * m_yLeftAxisCoefficient;
			poly << QPointF(x, y);
			++mapIt;
		}
		painter.drawPolyline(poly);
		++it;
	}
}

void DrawBoneArg::drawInspectResult(QPainter& painter)
{
	if (m_InspectResult.empty())return;
	auto it = m_InspectResult.begin();
	QPen pen(Qt::black);
	pen.setWidth(1);
	painter.setPen(pen);
	while (it != m_InspectResult.end())
	{
		double x = ((it->first - std::get<4>(m_dAxisMaxMinValue)) / m_iAgeOffset)* m_xAgeAxisCoefficient;
		double y = ((it->second - std::get<0>(m_dAxisMaxMinValue)) / m_dLeftYAxisOffset) * m_yLeftAxisCoefficient;
		QBrush br(Qt::white);
		painter.setBrush(br);
		painter.drawRect( QRectF(x-7.5, y-7.5, 15, 15));

		br.setColor(QColor(0, 0, 0));
		painter.setBrush(br);
		painter.drawRect(QRectF(x - 3.8, y - 3.8, 8, 8));
		++it;
	}
}