如何使用qt读取dwg文件中坐标信息

要在Qt中读取DWG文件中的坐标信息，可以使用DWG阅读器库，例如ODA的Teigha库。以下是一些示例代码，演示如何使用Teigha库和Qt读取DWG文件中的坐标信息：

#include <QtWidgets/QApplication>
#include <QtWidgets/QMainWindow>
#include <OdaCommon.h>
#include <Gi/GiViewport.h>
#include <Gi/GiGeometrySimplifier.h>
#include <Gi/GiSubEntityTraits.h>
#include <Gs/Gs.h>
#include <Ge/GeMatrix3d.h>
#include <RxVariantValue.h>
#include <RxObjectImpl.h>
#include <RxModule.h>

class DwgViewer : public QMainWindow, public OdGiGeometrySimplifier
{
public:
    DwgViewer(QWidget *parent = 0)
        : QMainWindow(parent)
    {
        OdRxModulePtr pMod = ::odrxDynamicLinker()->loadModule(OdString("TD_Root"));
        if (pMod.isNull())
            throw std::runtime_error("Cannot load Teigha module");

        OdRxModulePtr pRenderMod = ::odrxDynamicLinker()->loadModule(OdString("TD_Gs"));
        if (pRenderMod.isNull())
            throw std::runtime_error("Cannot load Teigha render module");

        m_pGsDevice = OdGsDevicePtr(OdGsDevice::createObject(), OdRxObjectImpl<OdGsDevice>);
        m_pGsView = OdGsViewPtr(OdGsView::createObject(), OdRxObjectImpl<OdGsView>);

        m_pGsView->setViewport(m_pGsDevice->createViewport());

        this->setCentralWidget(m_pGsView->viewport()->widget());

        this->resize(800, 600);

        OdDbDatabasePtr pDb = OdDbDatabase::createObject();
        if (pDb.isNull())
            throw std::runtime_error("Cannot create database");

        if (pDb->readDwgFile(OdString("<filepath>")) != eOk)
            throw std::runtime_error("Cannot read DWG file");

        OdDbBlockTablePtr pBlockTable = pDb->getBlockTable();
        if (!pBlockTable.isNull())
        {
            OdDbBlockTableRecordPtr pRecord;
            if (pBlockTable->getAt(OdString("Model_Space"), pRecord) != eOk)
                throw std::runtime_error("Cannot get Model_Space");

            OdDbBlockTableRecordIteratorPtr pIterator = pRecord->newIterator();
            while (!pIterator->done())
            {
                OdDbEntityPtr pEntity = pIterator->entity();
                if (!pEntity.isNull())
                {
                    pEntity->subOpen();
                    pEntity->subWorldDraw(this);
                    pEntity->subClose();
                }

                pIterator->step();
            }
        }

        m_pGsView->setViewportBorderWidth(0);

        m_pGsView->add(OdGsDevicePtr(m_pGsDevice));

        m_pGsDevice->setBackgroundColor(ODRGB(255, 255, 255));

        m_pGsView->invalidate();

        m_pGsView->update();
    }

    virtual void polylineOut(OdInt32 nbPoints, const OdGePoint3d* pVertexList)
    {
        // 处理每个多边形的坐标信息
        for (int i = 0; i < nbPoints; ++i)
        {
            OdGePoint3d point = pVertexList[i];
            // 处理坐标点，例如打印它们
            qDebug() << point.x << point.y << point.z;
        }
    }

private:
    OdGsDevicePtr m_pGsDevice;
    OdGsViewPtr m_pGsView;
};

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    try
    {
        DwgViewer viewer;
        viewer.show();
        a.exec();
    }
    catch (const std::exception& ex)
    {
        qDebug() << ex.what();
        return 1;
    }

    return 0;
}

请注意，上面的示例代码仅演示了如何读取DWG文件中的坐标信息，并打印出来。您可以根据您的实际需求，对代码进行更改和扩展。