一、演示效果

二、安装过程

三、核心程序

#include <QtGui>
#include <QColor>#include <cstdlib>
#include <cassert>
#include <numeric>#include <chartwork/PieChart.h>
#include <chartwork/Design.h>
#include <chartwork/exceptions/OutOfRangeException.h>
#include <chartwork/exceptions/EmptyException.h>
#include <chartwork/exceptions/UnknownItemException.h>namespace chartwork
{
//
// PieChart
//
PieChart::PieChart(QWidget *parent)
:	Chart(parent),m_fontMetrics(m_font),m_showPercentage(true),m_precision(1),m_labels(std::shared_ptr<QStringList>(new QStringList({"A", "B", "C", "D"}))),m_key(m_labels, m_colors)
{setWindowTitle(tr("Pie Chart"));resize(400, 300);setMinimumSize(200, 150);generateRandomValues();m_title.setText("Pie Chart");update();
}const QStringList &PieChart::labels() const
{return *m_labels;
}void PieChart::setLabels(const QStringList &labels)
{*m_labels = labels;m_key.updateSize();generateRandomValues();update();
}bool PieChart::showKey() const
{return m_key.isVisible();
}void PieChart::setShowKey(bool showKey)
{m_key.setVisible(showKey);update();
}double PieChart::keyScale() const
{return m_key.scale();
}void PieChart::setKeyScale(double keyScale)
{m_key.setScale(keyScale);update();
}bool PieChart::showPercentage() const
{return m_showPercentage;
}void PieChart::setShowPercentage(bool showPercentage)
{m_showPercentage = showPercentage;update();
}int PieChart::precision() const
{return m_precision;
}void PieChart::setPrecision(int precision)
{m_precision = std::max(0, precision);update();
}void PieChart::resetValues()
{m_values.clear();m_values.resize(m_labels->size(), 0.0);
}void PieChart::generateRandomValues()
{resetValues();std::srand(0);for (int i = 0; i < m_labels->size(); i++)m_values[i] = std::rand() / (double)RAND_MAX * 100;
}double PieChart::diameter(int remainingWidth, int remainingHeight) const
{return std::max(0.0, std::min((double)remainingWidth, (double)remainingHeight));
}void PieChart::paintEvent(QPaintEvent *)
{if (m_labels->empty())return;if (m_values.size() < (size_t)m_labels->size())return;m_title.setWidth(width());m_title.moveTopLeft(QPoint(0, design::spacing - m_title.rect().height() / 4));int remainingWidth = width() - m_key.rect().width() - 3 * design::spacing;if (!m_key.isVisible())remainingWidth += design::spacing;const int remainingHeight = height() - m_title.rect().height() - 2 * design::spacing;m_diameter = diameter(remainingWidth, remainingHeight);m_chartRect.setSize(QSize(m_diameter, m_diameter));const int outerSpacing = (remainingWidth - m_diameter) / 2;m_chartRect.moveLeft(design::spacing + outerSpacing);m_chartRect.moveTop(design::spacing + m_title.rect().height() + (remainingHeight - m_diameter) / 2);m_key.moveTopRight(QPoint(m_chartRect.left() + m_chartRect.width() + design::spacing + m_key.rect().width(), design::spacing + m_title.rect().height() + (remainingHeight - m_key.rect().height()) / 2));QPainter painter(this);m_background.paint(painter);m_title.paint(painter);paint(painter);m_key.paint(painter);
}void PieChart::paint(QPainter &painter)
{const double sumOfValues = std::accumulate(m_values.begin(),m_values.end(), 0.0, [](double sum, double v){return sum + std::max(0.0, v);});painter.setRenderHint(QPainter::Antialiasing);double currentAngle = 0;for (size_t i = 0; i < m_values.size(); i++){const double angleValue = m_values[i] / sumOfValues * 360 * 16;if (angleValue <= 0.0)continue;const QColor &color = (*m_colors)[i % m_colors->size()];painter.setBrush(color);painter.drawPie(m_chartRect, std::round(-currentAngle + 90 * 16 - angleValue), std::round(angleValue));currentAngle += angleValue;}painter.setRenderHint(QPainter::Antialiasing,false);if (!m_showPercentage)return;currentAngle = 0;for (size_t i = 0; i < m_values.size(); i++){const double angleValue = m_values[i] / sumOfValues * 2.0 * M_PI;if (angleValue <= 0.0)continue;const double midAngle = -currentAngle + M_PI_2 - angleValue / 2.0f;painter.setPen(Qt::SolidLine);painter.setFont(m_font);const QColor &color = (*m_colors)[i % m_colors->size()];if (color.value() < 210)painter.setPen(design::superlightgray);const QString percentageText = QString("%1").arg(m_values[i] / sumOfValues * 100.0, 0, 'f', m_precision) + QString(" %");const QPoint textCenter = m_chartRect.center() + QPoint(m_diameter / 3 * std::cos(midAngle), -m_diameter / 3 * std::sin(midAngle));const double textWidth = m_fontMetrics.width(percentageText) + 24;const double textHeight = m_fontMetrics.height() + 24;painter.drawText(QRect(textCenter.x() - textWidth / 2,textCenter.y() - textHeight / 2,textWidth,textHeight),percentageText, QTextOption(Qt::AlignCenter));painter.setPen(Qt::NoPen);currentAngle += angleValue;}
}void PieChart::setValue(int slice, double value)
{handleValueUpdate();if (m_values.empty())throw exceptions::EmptyException("PieChart", objectName(), "labels");if (slice < 0 || (size_t)slice >= m_values.size())throw exceptions::OutOfRangeException("PieChart", objectName(), "slice", slice, 0, (int)m_values.size() - 1);m_values[slice] = value;
}void PieChart::setValue(const QString &label, double value)
{if (m_values.empty())throw exceptions::EmptyException("PieChart", objectName(), "labels");const int sliceIndex = m_labels->indexOf(label);if (sliceIndex < 0)throw exceptions::UnknownItemException("PieChart", objectName(), "label", label, *m_labels);setValue(sliceIndex, value);
}void PieChart::setAllValues(double value)
{handleValueUpdate();m_values.clear();m_values.resize(m_labels->size(), value);
}double PieChart::value(int slice) const
{if (m_values.empty())throw exceptions::EmptyException("PieChart", objectName(), "labels");if (slice < 0 || (size_t)slice >= m_values.size())throw exceptions::OutOfRangeException("PieChart", objectName(), "slice", slice, 0, (int)m_values.size() - 1);return m_values[slice];
}double PieChart::value(const QString &label) const
{if (m_values.empty())throw exceptions::EmptyException("PieChart", objectName(), "labels");const int sliceIndex = m_labels->indexOf(label);if (sliceIndex < 0)throw exceptions::UnknownItemException("PieChart", objectName(), "label", label, *m_labels);return value(sliceIndex);
}}

四、程序链接

https://download.csdn.net/download/u013083044/88803860