求救：做对话框的高手帮帮忙！解决方法

求救：做对话框的高手帮帮忙！！！！
我用对话框做了个界面，现在关键就是在对话框的中部画一个圆形（圆形外围有0~360度的标尺），其内部可以显示图片，希望是对话框一运行这个圆就存在，可我现在找到的例子都是用鼠标动态画圆的，只有再这恳请各位帮忙了！！！

------解决方案--------------------
在OnPaint中：
CPaintDC dc(this); // device context for painting
CRect rect;
GetClientRect(&rect);
int r= min(rect.right - rect.left, rect.bottom -rect.top) / 2;
POINT m_Point;
m_Point.x = (rect.right + rect.left)/2;
m_Point.y = (rect.bottom + rect.top)/2;

rect.left = m_Point.x - r;
rect.top = m_Point.y - r;
rect.right = m_Point.x + r;
rect.bottom = m_Point.y + r;

HBRUSH *pBrush, *pOldBrush;
pBrush = (HBRUSH*)GetStockObject(NULL_BRUSH);
pOldBrush = (HBRUSH*)dc.SelectObject(pBrush);

dc.Ellipse(&rect);
dc.SelectObject(pOldBrush);
DeleteObject(pBrush);
CDialog::OnPaint();
------解决方案--------------------
画蓝色底色：
HBRUSH *pOldBrush
CBrush Brush;
Brush.CreateSolidBrush(RGB(0,0,255));
pOldBrush = (HBRUSH*)dc-> SelectObject(Brush);
dc-> Ellipse(0,0,200,200);
dc-> SelectObject(pOldBrush);
DeleteObject(Brush);

画黄色线条：
CPen *hOldPen, Pen;
Pen.CreatePen(PS_SOLID, 2, RGB(255,255,0));
hOldPen = (CPen *)dc-> SelectObject(&Pen);
dc-> MoveTo(0,100);
dc-> LineTo(200, 100);
dc-> SelectObject(&hOldPen);
DeleteObject(Pen);
------解决方案--------------------
PI = 3.1415926

POINT p;
dc-> SetROP2(R2_NOT)
for(int i = 0; i < 360; i++)
{
if (i > 0)//擦掉
{
p.x = int(半径 * cos((i-1) * PI / 180 )+圆心.x);
p.y = int(半径 * sin((i-1) * PI / 180 )+圆心.y);
}
p.x = int(半径 * cos(i * PI / 180 )+圆心.x);
p.y = int(半径 * sin(i * PI / 180 )+圆心.y);

}
------解决方案--------------------
void CDlgDlg::OnButton1()
{
// TODO: Add your control notification handler code here
CClientDC dc(this);
static int i = 0;
int r = 100;
double PI;
PI = 3.1415926;

POINT p, p1;
dc.SetROP2(R2_NOT);

p1.x =100;
p1.y = 100;

if (i > 0)//擦掉
{
p.x=int(r * cos((i-1) * PI / 180 )+p1.x);
p.y = int(r * sin((i-1) * PI / 180 )+p1.y);
dc.MoveTo(p1);
dc.LineTo(p);
}
p.x = int(r * cos(i * PI / 180 )+p1.x);
p.y = int(r * sin(i * PI / 180 )+p1.y);
dc.MoveTo(p1);
dc.LineTo(p);
i++;
}
}