CWindowDC dc(this);
HDC hdc=dc.GetSafeHdc();
using namespace Gdiplus;
Graphics graphics(hdc);
graphics.SetSmoothingMode(SmoothingModeHighQuality);
Pen newPen(Color(0,200,255),5);
graphics.DrawLine(&newPen, 50, N1, x2, y2);
ps：析构函数中什么也没有。
RE:
GetDC/GetSafeHdc需要调用ReleaseDC来释放： ::ReleaseDC(m_hWnd,hdc);
gdi+的资源new要对应delete(gdi的资源createxxx对应DeleteObject)
Pen = new Pen(Color(0,200,255),5);
delete Pen;
Pen = NULL;
-----------------------------------------------
CDC *pDC = GetDlgItem(IDC_WAVEFORM)->GetDC();
HDC hdc = pDC->GetSafeHdc(); if(!ReleaseDC(pDC) )//成功
{
printf("1 error code:%d\n",GetLastError());
} if(!DeleteObject(hdc))
{
printf("2 error code:%d\n",GetLastError());//失败 返回：6
}
请问在这里 pDC和hdc 都需要释放吗？还是只释放pDC，应该怎么去理解？
RE:
ReleaseDC(pDC）就行了，在Release(pDC)的过程中，会DeleteObject掉和pDC相关联的HDC的。