MFC类库之CArray作为函数参数和返回值
一、获得返回值:
可以作为函数的一个参数比如定义fun(CArray<int, int &> &array)采用引用类型,就可以直接使用二、作为函数参数:#include<Afxtempl.h>//定义函数。void ansnode(int num,CArray<double,double&> m_adX, CArray<double,double&> m_adY, CArray<double,double&> m_adZ); 函数体:void ansysdata::ansnode(int num,CArray<double,double&> *m_adX, CArray<double,double&> *m_adY, CArray<double,double&> *m_adZ){ double x, y,z; int i; fstream infilex; fstream infiley; fstream infilez; infilex.open("d:/intface/M_ADX.TXT.txt",ios::in); infiley.open("d:/intface/M_ADX.TXT.txt",ios::in); infilez.open("d:/intface/M_ADX.TXT.txt",ios::in); for (i=0;i<num;i++) { infilex>>x; infiley>>y; infilez>>z; m_adX.Add(x); m_adY.Add(y); m_adZ.Add(z); } fstream outfilex; fstream outfiley; fstream outfilez; outfilex.open("d:/intface/M_ADX1.TXT.txt",ios::in); outfiley.open("d:/intface/M_ADX2.TXT.txt",ios::in); outfilez.open("d:/intface/M_ADX3.TXT.txt",ios::in); for (i=0;i<num;i++) { outfilex<<m_adX.GetAt(i)<<endl; outfiley<<m_adY.GetAt(i)<<endl; outfilez<<m_adZ.GetAt(i)<<endl; }}三、CArray结构体中的应用struct DriverItem{ CString strDriverName; CString strProductDescribe; CString strTBLFileName;};struct ControlItem{ CString strControlType; CArray <DriverItem,DriverItem&> DriverArray;};四、CArray的简单说明CArray <Object,Object> Var1;CArray <Object,Object&> Var2;第一个参数是CArray的返回的参数,第二个参数是传递给CArray的参数。即,当使用第二种形式定义Carray数组时,使用Add()时是一个引用类型的参数。五、转帖最近一直在编写一个绘图程序,为了保存多个double型点坐标,这里我采用了定义集合类CArray<TYPE, ARG_TYPE>CPointDArray来保存多点,然后定义坐标转换函数ConvertToXYs(CPointDArray,long* xy),将double坐标转换为long型坐标,这是就出现几种常见错误,"CPointDArray缺少构造函数,或者是拷贝构造函数不存在”,‘不能将参数 1 从“CArray<TYPE,ARG_TYPE>”转换为“CArray<TYPE,ARG_TYPE>”,从这两个问题入手,举例说明问题。 下面代码为我修改多次后总结的一个实例,照着此方法可以推广:1.建立一个VC6工程 ,在CTestView中,添加一个OnLButtonDown,在这里实现点的绘制。2.在CTestView.h中,自定义double类型的点类以及数组class CPointD{public: double x; //longtitude double y; //latitude CPointD() { x =0; y=0; }; CPointD(const double dx,double dy) { x = dx; y = dy; }; CPointD(const CPointD& pnt) { x = pnt.x; y = pnt.y; }; CPointD& operator=(const CPointD& rhs) { if (this == &rhs) { return *this; } x = rhs.x; y = rhs.y; return *this; }};//double 型指针链表typedef CArray<CPointD,CPointD>CPointDArray; //double 型数组typedef CArray<POINT,POINT&>LPointArray;//long型数组注意这里CArray<CPointD,CPointD>可以用CArray<CPointD*,CPointD*>,实验证明没有问题。3.在视图类CTestView定义全局变量CPointDArray plist;定义函数void ConvToXYs(const CPointDArray &alist, LPointArray& llist);//&alist为常应用,保存函数中不修改数据,&llist是alist转//换成long后的数组。这里就是出现上述常见问题的症结。下面为实现部分void CTestLineView::ConvToXYs(const CPointDArray &alist, LPointArray& llist){ if (alist.GetSize()>0) { llist.RemoveAll(); int i ; int n = alist.GetSize(); llist.SetSize(n); double jing, wei; for(i=0;i<n;i++) { CPointD p = alist.GetAt(i); jing = p.x; wei = p.y; llist[i].x = (long)(jing+0.5);//这是关键步骤,可以当数组用 llist[i].y = (long)(wei+0.5);// }4.在鼠标左键事件中实现绘制:void CTestLineView::OnLButtonDown(UINT nFlags, CPoint point){ CClientDC pDC(this); try { CPen* pOldPen = (CPen*)pDC.SelectStockObject(2); for (int i=0;i<10;i++) { // CPointD *p=new CPointD(i*3.5f,i*5.5f); plist.Add(CPointD(i*3.5f,i*5.5f)); } LPointArray longpoints; ConvToXYs(plist,longpoints); pDC.Polyline(longpoints.GetData(),plist.GetSize()); CString str; str.Format("%d",longpoints.GetSize()); AfxMessageBox(str,MB_OK); // Restore the original device context objects. pDC.SelectObject(pOldPen); }catch (CException* e){ LPTSTR lp="" ; e->GetErrorMessage(lp,250); AfxMessageBox(lp);}CView::OnLButtonDown(nFlags, point);}最后在~CTestLineView中清除plist。CTestLineView::~CTestLineView(){ if(plist.GetSize()) plist.RemoveAll();}大概就这么多了,通过学习,希望能够给大家一个思路,将来能够很娴熟的应用CArray。http://blog.csdn.net/eattonton/article/details/5278540声明:本站所有文章资源内容,如无特殊说明或标注,均为采集网络资源。如若本站内容侵犯了原著者的合法权益,可联系本站删除。