#include "math.h"

define Pi 3.1415927
void CMfcSdiSampleView::OnDraw(CDC pDC)
{
    CMfcSdiSampleDoc pDoc = GetDocument();
    ASSERT_VALID(pDoc);
    if (!pDoc)
        return;

// TODO: add draw code for native data here
CRect rect;
GetClientRect(&rect);
int radius=800;
pDC->SetMapMode(MM_ISOTROPIC);
pDC->SetWindowExt(radius+100,radius+100);
pDC->SetViewportExt(rect.right/2,-rect.bottom/2);
pDC->SetViewportOrg(rect.right/2,rect.bottom/2);

//獲取內容狀態信息
MEMORYSTATUS mem;
::GlobalMemoryStatus(&mem);
SIZE_T MemTotal=mem.dwTotalPhys;
SIZE_T MemAvail=mem.dwAvailPhys;
double dFree=(double)(Pi*2*MemAvail/MemTotal);
double dUsed=(double)Pi*2-dFree;
int x=-(int)(sin(dUsed)*radius);
int y= (int)(cos(dUsed)*radius);

CPen pen1,pen2,*oldpen;
CBrush brush1,brush2,*oldbrush;
//繪制已用
pen1.CreatePen(PS_SOLID,50,RGB(255,0,0));
brush1.CreateSolidBrush(RGB(255,0,0));
oldpen=pDC->SelectObject(&pen1);
oldbrush=pDC->SelectObject(&brush1);
pDC->Pie(-radius,radius,radius,-radius,0,radius,x,y);
pDC->SelectObject(oldpen);
pDC->SelectObject(oldbrush);
//繪制未用
brush2.CreateSolidBrush(RGB(0,160,255));
pen2.CreatePen(PS_SOLID,50,RGB(0,160,255));
oldpen=pDC->SelectObject(&pen2);
oldbrush=pDC->SelectObject(&brush2);
pDC->Pie(-radius,radius,radius,-radius,x,y,0,radius);
pDC->SelectObject(oldpen);
pDC->SelectObject(oldbrush);

pDC->SetBkMode(TRANSPARENT);
CString str;
str.Format(_T("Total: %dKB"),MemTotal/1024); //物理總內存
pDC->TextOut(300,300,str);
str.Format(_T("Available: %dKB"),MemAvail/1024); //剩余內存
pDC->TextOut(300,200,str);

}
void CMfcSdiSampleView::OnTimer(UINT_PTR nIDEvent)
{
    // TODO: Add your message handler code here and/or call default
    Invalidate();
    CView::OnTimer(nIDEvent);
}
int CMfcSdiSampleView::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
    if (CView::OnCreate(lpCreateStruct) == -1)
        return -1;

// TODO:  Add your specialized creation code here
SetTimer(1,1000,NULL);
return 0;

}</pre>