int x = rcImg.left + (imgWidth - nBmpWidth) / 2;
int y = rcImg.top + (rcImg.bottom - rcImg.top - nBmpHeight) / 2;
dc.Blit(x, y, nBmpWidth, nBmpHeight, &dcMem, 0, 0, wxCOPY, true);
int x = rcImg.left + (imgWidth - nBmpWidth) / 2;
int y = rcImg.top + (rcImg.bottom - rcImg.top - nBmpHeight) / 2;
dc.Blit(x, y, nBmpWidth, nBmpHeight, &dcMem, 0, 0, wxCOPY, true);