#include<afxwin.h>
#include<afxext.h>

#define SeedRand() srand(UINT)::GetTickCount()

class CMyApp:public CWinApp{
    public:
        virtual BOOL InitInstance();
};

class CMainWnd:public CFrameWnd{
    protected:
        int  m_nCurScreen;
        CPoint rec_E;
        int R_rec;
        int L_rec;
        COLORREF GetRandomColor();
        UINT MapRand(UINT nMax);
        void Growing_Ellipse(CClientDC *pDC);
    public:
        CMainWnd();
        afx_msg void OnTimer(UINT IDtimer);
        DECLARE_MESSAGE_MAP();
};

//#include "CDCDEMO.H"
BEGIN_MESSAGE_MAP(CMainWnd,CFrameWnd)
    ON_WM_TIMER()
END_MESSAGE_MAP()

CMainWnd::CMainWnd(){
    rec_E.x=320;
    rec_E.y=480;
    R_rec=30;
    L_rec=10;
    SeedRand();   //这一句有俩个错误：D:\visual c++\MSDev98\MyProjects\MFC Ellipse\ellipse.cpp(36) : error C2275: 'UINT' : illegal use of this type as an expression
        d:\vc98\include\windef.h(162) : see declaration of 'UINT'
D:\visual c++\MSDev98\MyProjects\MFC Ellipse\ellipse.cpp(36) : error C2143: syntax error : missing ';' before 'tag::id'
为什么会有这俩个错误？？？？？？？？？

}

COLORREF CMainWnd::GetRandomColor(){
    return RGB(MapRand(255),MapRand(255),MapRand(255));
}

UINT CMainWnd::MapRand(UINT nMax){
    int nRand=rand();
    float fMap=(float)nMax/RAND_MAX;
    float fRetVal=(float)nRand*fMap+0.5F;
    return (UINT)fRetVal;
}

void CMainWnd::OnTimer(UINT IDtimer){
    CClientDC dc(this);
    Growing_Ellipse(&dc);
}

void CMainWnd::Growing_Ellipse(CClientDC *pDC){
    CBrush ColorBrush(GetRandomColor());
    pDC->SelectObject(&ColorBrush);
    pDC->Ellipse(rec_E.x-R_rec,rec_E.y-R_rec*480/640,
        rec_E.x+R_rec,rec_E.y+R_rec*480/640);
    R_rec=R_rec+C_rec;  //D:\visual c++\MSDev98\MyProjects\MFC Ellipse\ellipse.cpp(60) : error C2065: 'C_rec' : undeclared identifier

    if(rec_E-R_rec<=10||rec_E-R_rec>=300) C_rec-=C_rec; //  这一句也有俩个错误,为什么？？？ D:\visual c++\MSDev98\MyProjects\MFC Ellipse\ellipse.cpp(61) : error C2679: binary '-' : no operator defined which takes a right-hand operand of type 'int' (or there is no acceptable conversion)
D:\visual c++\MSDev98\MyProjects\MFC Ellipse\ellipse.cpp(61) : error C2679: binary '-' : no operator defined which takes a right-hand operand of type 'int' (or there is no acceptable conversion)
}

BOOL CMyApp::InitInstance(){
    CMainWnd *pFrame=new CMainWnd;
    pFrame->Create(0,"Graphics Demo",WS_POPUPWINDOW|WS_DLGFRAME,CRect(0,0,640,480));
    this->m_pMainWnd=pFrame;
    pFrame->ShowWindow(m_nCmdShow);
    pFrame->UpdateWindow();
    pFrame->SetTimer(0,50,NULL);
    return TRUE;
}

CMyApp MyApp;

编译后产生如下错误，望高手们帮助修改，并告诉我出错的原因，感激不尽！！！！！！！！？？？？？？？？？？
///////////////////////////////////////////////////////////////////////////////////////
--------------------Configuration: MFC Ellipse - Win32 Debug--------------------
Compiling...
ellipse.cpp
D:\visual c++\MSDev98\MyProjects\MFC Ellipse\ellipse.cpp(36) : error C2275: 'UINT' : illegal use of this type as an expression
        d:\vc98\include\windef.h(162) : see declaration of 'UINT'
D:\visual c++\MSDev98\MyProjects\MFC Ellipse\ellipse.cpp(36) : error C2143: syntax error : missing ';' before 'tag::id'
D:\visual c++\MSDev98\MyProjects\MFC Ellipse\ellipse.cpp(60) : error C2065: 'C_rec' : undeclared identifier
D:\visual c++\MSDev98\MyProjects\MFC Ellipse\ellipse.cpp(61) : error C2679: binary '-' : no operator defined which takes a right-hand operand of type 'int' (or there is no acceptable conversion)
D:\visual c++\MSDev98\MyProjects\MFC Ellipse\ellipse.cpp(61) : error C2679: binary '-' : no operator defined which takes a right-hand operand of type 'int' (or there is no acceptable conversion)
Error executing cl.exe.

MFC Ellipse.exe - 5 error(s), 0 warning(s)

C_rec没定义，当然报错。

#define   SeedRand()   srand((UINT)::GetTickCount())   

能帮忙改改吗？

都说到这份上了，自己写出一下吧。代码不想细看了，大学课程的题目。

新手路过学习一下