LOGFONT lf = { 0 };
::GetObject(::GetStockObject(DEFAULT_GUI_FONT), sizeof(LOGFONT), &lf);
_tcscpy(lf.lfFaceName, _T("Microsoft YaHei"));
lf.lfCharSet = DEFAULT_CHARSET;
lf.lfHeight = -14;
HFONT hFont = ::CreateFontIndirect(&lf);
RETURN_IF(!hFont);
HDC hdc = ::GetDC(this->GetHWND());
HFONT hOldFont = (HFONT) ::SelectObject(hdc, hFont);
SIZE sz;
wstring strFileName = L"ajsdjasjkdjkajskdkja";
::GetTextExtentPoint32(hdc, strFileName.c_str(), strFileName.c_str(), &sz);
::SelectObject(hdc, hOldFont);
::DeleteObject(hFont);
sz即表示字符串的宽度和高度