最近在做文字绘制，需要用到绘制文字轮廓，发现QT里面有自己的解决方案，分享出来；

具体贴代码

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QPainter>


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

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


//************************************
// 名    称	: GetMaximumOuterContour
// 创建日期	：2023/01/10
// 参    数	: const QPainterPath &path_ 目标Path
// 返 回 值	：QPainterPath   返回Path
//************************************
QPainterPath GetMaximumOuterContour(const QPainterPath &path_)
{
    QPainterPath path;
    QPainterPath* ppath = new QPainterPath();
    QPainterPath path_new;
    QVector<QPainterPath*> arrPath;
    QVector<QPointF> list;
    QPointF op;
    QPointF sp, c1, c2, ep;
    int cCount = 0;
    bool first = true;
    bool bfirstadd = true;
    size_t count = path_.elementCount();
    for (int i = 0; i < count; ++i) {
        QPainterPath::ElementType type = path_.elementAt(i).type;
        qreal x = path_.elementAt(i).x;
        qreal y = path_.elementAt(i).y;

        QPointF pt = QPointF(x, y);
        if (first)
        {
            op = pt;
            first = false;
        }

        if (type == QPainterPath::CurveToElement) {
            sp = op;
            c1 = pt;
            cCount = 0;
        }
        else if (type == QPainterPath::CurveToDataElement) {
            cCount++;
            if (cCount == 1)
            {
                c2 = pt;
            }
            else if (cCount == 2)
            {
                ep = pt;
                cCount = 0;
                ppath->cubicTo(c1, c2, ep);
            }
        }
        else if (type == QPainterPath::MoveToElement) {
           // path_new = path_new.united(path);
          // if(!bfirstadd)
           {
           //   arrPath.push_back(ppath);
           }
          //  ppath = new QPainterPath();
            ppath->moveTo(x, y);
            bfirstadd = false;
        }
        else if (type == QPainterPath::LineToElement) {
            ppath->lineTo(x, y);
        }
        op = pt;
    }

  //  path_new = path_new.united(path);
    arrPath.push_back(ppath);
//    auto itr = arrPath.begin();
//    auto itr_end = arrPath.end();
//    for(auto itr_i = itr;itr_i != itr_end;itr_i++)
//    {
//        path_new = path_new.united(**itr);
//    }

    path_new = path_new.united(*arrPath[0]);
    QPainterPath path_new2 = path_new;
  //  path_new2 = path_new.united(*arrPath[1]);
    return path_new2;
}




 void MainWindow::paintEvent(QPaintEvent*)
 {
    QPainter painter(this);


    // 创建一个QPainterPath对象
       QPainterPath path;

       // 设置字体
       QFont font;
       font.setPointSize(100);
       font.setFamily("Arial");

       // 设置字符
       QString text = "A武汉市江夏区";

       // 在QPainterPath中添加字符路径
       path.addText(0, 0, font, text);

       // 创建一个QPainterPathStroker对象
       QPainterPathStroker stroker;
       stroker.setWidth(20);

       // 使用QPainterPathStroker获取字符的外轮廓
       QPainterPath outline = stroker.createStroke(path);
       painter.setRenderHint(QPainter::Antialiasing);
       painter.setPen(Qt::black);
       painter.drawPath(outline);


 }

void MainWindow::on_actionAddText_triggered()
{
    // 创建一个QPainterPath对象
    QPainterPath path;
    // 设置字体
        QFont font;
        font.setPointSize(300);
        font.setFamily("Arial");

        // 设置字符
        QString text = "A武汉市犄角旮旯饕餮道魑魅魍魉\nABCDEGFHIJKLMNOPQRSTUVWXYZ 123456789~!@#$%^&*()_+|[]?';.<>";
      //  QString text = "A";

        // 在QPainterPath中添加字符路径
        path.addText(200,500, font, text);

        // 创建一个QPainterPathStroker对象
        QPainterPathStroker stroker;
        stroker.setWidth(2);

        // 使用QPainterPathStroker获取字符的外轮廓
        QPainterPath outline = stroker.createStroke(path);

    // 创建一个QImage对象，并设置背景为白色
    QImage image(30000, 1000, QImage::Format_ARGB32);
    image.fill(Qt::white);
    // 在QImage上绘制外轮廓
    QPainter painter(&image);
    painter.setRenderHint(QPainter::Antialiasing);
    painter.setPen(Qt::black);
    painter.drawPath(outline);
    // 保存图片
    image.save("outline.png");

    QPainterPath newoutline  = GetMaximumOuterContour(path);

    QImage image1(30000, 1000, QImage::Format_ARGB32);
    image1.fill(Qt::white);
    // 在QImage上绘制外轮廓
    QPainter painter1(&image1);
    painter1.setRenderHint(QPainter::Antialiasing);
    painter1.setPen(Qt::red);
    painter1.drawPath(newoutline);
    // 保存图片
    image1.save("newoutline.png");

}