qcustomplot绘制柱状图

使用QCustomPlot绘制柱状图的具体步骤如下：

1. 创建QCustomPlot对象并设置其大小和标题。

QCustomPlot *customPlot = new QCustomPlot(this);
customPlot->setFixedSize(500, 300);
customPlot->plotLayout()->insertRow(0);
customPlot->plotLayout()->addElement(0, 0, new QCPTextElement(customPlot, "柱状图", QFont("sans", 12, QFont::Bold)));

2. 创建QCPBars对象并设置其数据和颜色。

QCPBars *bars = new QCPBars(customPlot->xAxis, customPlot->yAxis);
bars->setData(x, y); // x和y分别为 QVector<double> 类型的数据
bars->setBrush(QColor(255, 131, 0));

3. 设置X轴和Y轴的范围和标签。

customPlot->xAxis->setRange(0, x.size());
customPlot->xAxis->setTickVectorLabels(labels); // labels为 QVector<QString> 类型的标签
customPlot->yAxis->setRange(0, 10);
customPlot->xAxis->setLabel("X轴标签");
customPlot->yAxis->setLabel("Y轴标签");

4. 更新图表。

customPlot->replot();

完整的代码示例：

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "qcustomplot.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    // 创建QCustomPlot对象并设置其大小和标题
    QCustomPlot *customPlot = new QCustomPlot(this);
    customPlot->setFixedSize(500, 300);
    customPlot->plotLayout()->insertRow(0);
    customPlot->plotLayout()->addElement(0, 0, new QCPTextElement(customPlot, "柱状图", QFont("sans", 12, QFont::Bold)));

    // 设置数据
    QVector<double> x = QVector<double>() << 1 << 2 << 3 << 4 << 5;
    QVector<double> y = QVector<double>() << 2 << 4 << 6 << 8 << 10;
    QVector<QString> labels = QVector<QString>() << "A" << "B" << "C" << "D" << "E";

    // 创建QCPBars对象并设置其数据和颜色
    QCPBars *bars = new QCPBars(customPlot->xAxis, customPlot->yAxis);
    bars->setData(x, y);
    bars->setBrush(QColor(255, 131, 0));

    // 设置X轴和Y轴的范围和标签
    customPlot->xAxis->setRange(0, x.size());
    customPlot->xAxis->setTickVectorLabels(labels);
    customPlot->yAxis->setRange(0, 10);
    customPlot->xAxis->setLabel("X轴标签");
    customPlot->yAxis->setLabel("Y轴标签");

    // 更新图表
    customPlot->replot();
}

MainWindow::~MainWindow()
{
    delete ui;
}