[求助]：刚学习自定义实体，出现了问题，请指教！

yoursmile

我从AcDbEntity派生了一个子类AzhtEntity，然后又从AzhtEntity派生AzhtBreaker，如下：一些必须的重载函数还有些返回值都已省略，
AzhtEntity中：
class AzhtEntity:public AcDbEntity
{
public:
        ACRX_DECLARE_MEMBERS(AzhtEntity);
        AzhtEntity();
                     virtual ~AzhtEntity();
.....................................
.....................................
..................moveGripPointsAt()..........
..................getGripPoints()................
..................transformBy()..................
.........................................................
........................................................
private:
        AcGePoint3d m_insertPt;        //插入点
};

AzhtEntity::getGripPoints(AcGePoint3dArray& gripPoints, AcDbIntArray& osnapModes, AcDbIntArray& geomIds) const
{
        assertReadEnabled();
        gripPoints.append(m_insertPt);
        return Acad::eOk;
}

AzhtEntity::moveGripPointsAt(const AcDbIntArray& indices, const AcGeVector3d& offset)
{
        assertWriteEnabled();
        return Acad::eOk;
}

AzhtEntity::transformBy(const AcGeMatrix3d& xform)
{
        assertWriteEnabled();
        return Acad::eOk;
}
AzhtBreaker中：
class AzhtBreaker:public AzhtEntity
{
public:
        ACRX_DECLARE_MEMBERS(AzhtBreaker);
        AzhtBreaker();
        virtual ~AzhtBreaker();
.....................................
.....................................
..................moveGripPointsAt()..........
..................getGripPoints()................
..................transformBy()..................
.........................................................
........................................................
private:
        AcGePoint3d m_otherPt;        //插入点
};
AzhtBreaker::getGripPoints(AcGePoint3dArray& gripPoints, AcDbIntArray& osnapModes, AcDbIntArray& geomIds) const
{
        assertReadEnabled();
        int iDirection = ((AzhtEntity*)this)->getDirection();
        AcGePoint3d insertPt = ((AzhtEntity*)this)->getInsertPt();
        gripPoints.append(m_otherPt);
        AzhtEntity::getGripPoints(gripPoints, osnapModes, geomIds);
        return Acad::eOk;
}

AzhtBreaker::moveGripPointsAt(const AcDbIntArray& indices, const AcGeVector3d& offset)
{
        assertWriteEnabled();
        //若没有选中点或偏移为0
        if(indices.length()==0 || offset.isZeroLength())
                return Acad::eOk;
        return transformBy(AcGeMatrix3d::translation(offset));
}

AzhtBreaker::transformBy(const AcGeMatrix3d& xform)
{
        assertWriteEnabled();
        AcGePoint3d insertPt = getInsertPt();
        insertPt.transformBy(xform);
        m_otherPt.transformBy(xform);
       
        return Acad::eOk;
}

我这样做之后，能够得到夹点，但在移动的时候出现问题，说什么内存不足！请高手指教一下，谢谢！！！！！！

missyou0515

最初由 yoursmile 发布
[B]AzhtEntity::getGripPoints(AcGePoint3dArray& gripPoints, AcDbIntArray& osnapModes, AcDbIntArray& geomIds) const
{
assertReadEnabled();
gripPoints.append(m_insertPt);
return Acad::eOk;
}
[/B]

这个函数可能有问题，因为getGripPoints会连续不断的执行，gripPoints最终会变得很大，应该进行清空处理。

binbin

最初由 missyou0515 发布
[B][QUOTE]最初由 yoursmile 发布
[B]AzhtEntity::getGripPoints(AcGePoint3dArray& gripPoints, AcDbIntArray& osnapModes, AcDbIntArray& geomIds) const
{
assertReadEnabled();
gripPoints.append(m_ins... [/B]

说得不对.
请把工程上传上来,我帮你改改

yoursmile

恩，好的，谢谢binbin
我是在VC++.net2002+AutoCAD2005下做的

binbin

代码已经帮你改完,问题在于字符串的处理

注意下面的代码

子类的构造必须调用父类的构造,下面的你都写了,这个构造你为什么不写呢
AzhtBreaker::AzhtBreaker():AzhtEntity()
{}

//增加了程序的稳定性,但用指针依然非常危险,,如果m_lpPlantName 没有被赋值,在调用dwgOutFields时会引起异常,建议使用cstring
AzhtEntity::AzhtEntity()
{
        m_lpPlantName = NULL;
        m_lpTypeNum = NULL;
        m_lpNumber = NULL;
}


        acutDelString(m_lpPlantName);
        pFiler->readString(&m_lpPlantName);
        acutDelString(m_lpTypeNum);
        pFiler->readString(&m_lpTypeNum);
        acutDelString(m_lpNumber);
        pFiler->readString(&m_lpNumber);

和

        if(m_lpPlantName !=        NULL)
                pFiler->writeString(m_lpPlantName);
        if(m_lpTypeNum != NULL)
                pFiler->writeString(m_lpTypeNum);
        if(m_lpNumber != NULL)
                pFiler->writeString(m_lpNumber);

并不匹配

还有
ACRX_DXF_DEFINE_MEMBERS(AzhtBreaker, AcDbEntity, AcDb::kDHL_CURRENT, AcDb::kMReleaseCurrent, 0, BREAKER, "Test")
书写错误,父类写错了

AzhtBreaker::moveGripPointsAt() 函数实现不正确,请不要调用transformBy

AzhtBreaker::transformBy() 函数       
AcGePoint3d insertPt = getInsertPt();
insertPt.transformBy(xform);
有误

我把改好的工程给你,应该不会出现 说什么内存不足！了,功能你得自己改

yoursmile

呵呵，谢谢binbin，你太热心了，万分感谢！我还想知道就是这个自定义对象的移动会激发哪些函数的调用呢？
我在想：AzhtBreaker::moveGripPointsAt() 函数为什么不能调用transformBy呢？只有移动了，然后调用transformBy来进行实体中各个点的矩阵变换了嘛！这个好像在SDK的文档里面都是这样的呀

还有
acutDelString(m_lpPlantName);
pFiler->readString(&m_lpPlantName);
acutDelString(m_lpTypeNum);
pFiler->readString(&m_lpTypeNum);
acutDelString(m_lpNumber);
pFiler->readString(&m_lpNumber);

和

if(m_lpPlantName != NULL)
pFiler->writeString(m_lpPlantName);
if(m_lpTypeNum != NULL)
pFiler->writeString(m_lpTypeNum);
if(m_lpNumber != NULL)
pFiler->writeString(m_lpNumber);

为什么不匹配呢，SDK中好像也是这样的呀

hehengw

问题已解决

empireman

我正想看看自定义实体如何实现，谢谢您的例子~~~