VC++开发GIS系统（229）修改区属性之类的设计及实现

本文为修改区的属性的操作设计一个类，以实现区属性的相关操作。

类的定义

在_malaPolygon.h中定义修改区属性的类，代码如下：

/*
* 修改区属性
*/
class malapolygondll  CmalaPolysModify :public CmalaMouseAction
{
public:
    CmalaPolysModify(CView* mView, malaScreen *pScreen, CString &fileFullPath);
    ~CmalaPolysModify();
    void LButtonDown(UINT nFlags, malaPoint point);
    void LButtonUp(UINT nFlags, malaPoint point);
    void MouseMove(UINT nFlags, malaPoint point);
private:
    bool mSelected;
    vector<malaPoint> mSPoly;//选择的区
    malaPolyPro mSPolyPro;//选择的区的属性
    CmalaPolysSelect mSelectPoly;

    CString mPath;//文件路径
    malaScreen *mScreen;
};

• m_Selected 用来定义区是否被选中
• mSPoly 记录选择的区的点序列
• mSPolyPro 记录选择区的属性
• mSelectPoly 一个选择区对象，用来选择区
• \*m_Screen 屏幕坐标变换变量
• mPath 文件路径

类的实现

在_malaPolygon.cpp中实现上述类，代码如下：

/*
* 修改区属性实现
*/
CmalaPolysModify::CmalaPolysModify(CView* mView, malaScreen *pScreen, CString &fileFullPath)
{
    mBaseView = mView;
    mPath = fileFullPath;
    mScreen = pScreen;
    CmalaPolysSelect obj(mView, pScreen, fileFullPath);
    mSelectPoly = obj;
    mSelected = FALSE;
}

CmalaPolysModify::~CmalaPolysModify()
{
    if (mSPoly.size())
        mSPoly.clear();
}

void CmalaPolysModify::LButtonDown(UINT nFlags, malaPoint point)
{
    if (!mSelected)
        mSelectPoly.LButtonDown(nFlags, point);
    
}

void CmalaPolysModify::LButtonUp(UINT nFlags, malaPoint point)
{
    if (!mSelected)
        mSelectPoly.LButtonUp(nFlags, point);

    mSelected = mSelectPoly.m_Selected;

    if (mSelected)
    {
        this->mSPoly = mSelectPoly.mSPoly;
        this->mSPolyPro = mSelectPoly.mSPolyPro;

        if (dlgModifyPolyPro(mSPolyPro))
        {
            CPolyIO lio;
            lio.polyUpdate(mSPoly, mSPolyPro, mPath);
            mBaseView->Invalidate(TRUE);
        }
        mSPoly.clear();
        mSelected = FALSE;
        mSelectPoly.m_Selected = FALSE;
    }

}

void CmalaPolysModify::MouseMove(UINT nFlags, malaPoint point)
{
    if (!mSelected)
        mSelectPoly.MouseMove(nFlags, point);
}

通过调用 polyUpdate函数实现区文件属性的修改，可以参考文章《VC++开发GIS系统（223）移动区之更新区参数》

详细代码可以参考：GitHub