SQL语句导入导出大全

这是《VC++动态链接库(DLL)编程深入浅出》的第四部分，阅读本文前，请先阅读前三部分：（一）
、（二）
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　　MFC扩展DLL的内涵为MFC的扩展，用户使用MFC扩展DLL就像使用MFC本身的DLL一样。除了可以在MFC扩展DLL的内部使用MFC以外，MFC扩展DLL与应用程序的接口部分也可以是MFC。我们一般使用MFC扩展DLL来包含一些MFC的增强功能，譬如扩展MFC的CStatic、CButton等类使之具备更强大的能力。
　　使用Visual C++向导生产MFC扩展DLL时，MFC向导会自动增加DLL的入口函数DllMain：
extern "C" int APIENTRY
DllMain(HINSTANCE hInstance, DWORD dwReason, LPVOID lpReserved)
{
 // Remove this if you use lpReserved
 UNREFERENCED_PARAMETER(lpReserved);
 if (dwReason == DLL_PROCESS_ATTACH)
 {
  TRACE0("MFCEXPENDDLL.DLL Initializing!\n");
  // Extension DLL one-time initialization
  if (!AfxInitExtensionModule(MfcexpenddllDLL, hInstance))
   return 0;
  // Insert this DLL into the resource chain
  // NOTE: If this Extension DLL is being implicitly linked to by
  //  an MFC Regular DLL (such as an ActiveX Control)
  //  instead of an MFC application, then you will want to
  //  remove this line from DllMain and put it in a separate
  //  function exported from this Extension DLL.  The Regular DLL
  //  that uses this Extension DLL should then explicitly call that
  //  function to initialize this Extension DLL.  Otherwise,
  //  the CDynLinkLibrary object will not be attached to the
  //  Regular DLL's resource chain, and serious problems will
  //  result.
  new CDynLinkLibrary(MfcexpenddllDLL);
 }
 else if (dwReason == DLL_PROCESS_DETACH)
 {
  TRACE0("MFCEXPENDDLL.DLL Terminating!\n");
  // Terminate the library before destructors are called
  AfxTermExtensionModule(Mf