=====================================Widget.h=====================================
#ifndef WIDGET_H
#define WIDGET_H
#include <QWidget>
namespace Ui {
    class Widget;
}
class Widget : public QWidget {
    Q_OBJECT
public:
    Widget(QWidget *parent = 0);
    ~Widget();
protected:
    virtual void changeEvent(QEvent *e);
    virtual bool eventFilter(QObject *watched, QEvent *e);
    void paintOnWidget(QWidget *w);
private:
    Ui::Widget *ui;
};
#endif // WIDGET_H
=====================================Widget.cpp=====================================
#include "Widget.h"
#include "ui_Widget.h"
#include <QtGui/QPainter>
Widget::Widget(QWidget *parent) : QWidget(parent), ui(new Ui::Widget) {
    ui->setupUi(this);
    ui->widget->installEventFilter(this);
}
Widget::~Widget() {
    delete ui;
}
void Widget::changeEvent(QEvent *e) {
    QWidget::changeEvent(e);
    switch (e->type()) {
    case QEvent::LanguageChange:
        ui->retranslateUi(this);
        break;
    default:
        break;
    }
}
bool Widget::eventFilter(QObject *watched, QEvent *e) {
    if (watched == ui->widget) {
        if (e->type() == QEvent::Paint) {
            paintOnWidget(ui->widget);
            return true;
        }
    }
    return QWidget::eventFilter(watched, e);
}
void Widget::paintOnWidget(QWidget *w) {
    QPainter painter(w);
    QFontMetrics metrics = painter.fontMetrics();
    int textHeight = metrics.ascent() + metrics.descent();
    int leftWidth = metrics.width(tr("9000")) + 5;
    int rightWidth = metrics.width(tr("(日)"));
    int width = w->size().width() - leftWidth - rightWidth;
    int height = w->size().height() - 3 * textHeight;
    // 绘制外框
    painter.drawRect(0, 0, w->size().width() -1, w->size().height() - 1);
    // 移动坐标系
    //painter.translate(inset * 2, ui->yearWidget->size().height() - inset);
    painter.translate(leftWidth, 1.75 * textHeight + height);
    int totalCount = 9000; // 默认每年收入9000件衣服
    int count = 10;        // 分成10成
    float deltaX = width / 12.0f;         // x坐标上每分的宽度
    float deltaY = (float)height / count; // y坐标上每分的宽度
    // 画横坐标
    painter.drawLine(0, 0, width, 0);
    for (int i = 1; i <= 12; ++i) {
        QString month = tr("%1月").arg(i);
        int stringWidth = metrics.width(month);
        // 绘制坐标刻度
        painter.drawLine(deltaX * i, 0, deltaX * i, 4);
        // 绘制坐标处的月
        int monthX = deltaX * (i - 1) + ((deltaX - stringWidth) / 2);
        painter.drawText(monthX, textHeight, month);
    }
    // 画纵坐标
    painter.drawLine(0, 0, 0, -height);
    painter.drawText(-metrics.width(tr("(件)")),
                     -(deltaY * count + textHeight / 2 + metrics.descent()),
                     tr("(件)"));
    for (int i = 1; i <= count; ++i) {
        QString value = QString("%1").arg(i * totalCount / count);
        int stringWidth = metrics.width(value);
        // 绘制坐标刻度
        painter.drawLine(-4, -i * deltaY, 0, -i * deltaY);
        // 绘制坐标值
        //painter.drawText(-stringWidth - 4, -i * deltaY + stringHeight / 2, value);
        painter.drawText(-stringWidth - 4, -(deltaY * i + textHeight / 2 - metrics.ascent()), value);
    }
    //    // 绘制每个月收到的服饰
    //    painter.setBrush(Qt::BDiagPattern);
    //    for (int i = 0; i < yearList.size(); ++i) {
    //        painter.setPen(Qt::black);
    //        int fineryCount = yearList.at(i); // 第i + 1个月收到的服饰件数
    //        int h = fineryCount / (float)totalCount * height;
    //        painter.drawRect(deltaX * i + 2, 0, deltaX - 4, -h);
    //
    //        // 绘制收到的服饰件数
    //        QString fineryString = QString("%1").arg(fineryCount);
    //        int stringWidth = metrics.width(fineryString);
    //
    //        if (h > height) {
    //            h = height;
    //        }
    //
    //        painter.setPen(Qt::red);
    //        //painter.drawText(deltaX * i + (deltaX - stringWidth) / 2, -(h + metrics.descent()), fineryString);
    //    }
}