Question

这是我在stackoverflow的第一篇文章，我开始遇到问题。

我在c ++中用qt编写了一个gui应用程序。目前我仍然坚持加载和保存传递给我的dll。为了加载和保存，我决定设置加载和保存任务的功能。但主要问题是加载不同的DLL文件。

我目前有以下代码用于加载和保存，但是当我从加载切换到保存时出现错误。我知道它与“FreeLibrary（）”功能有关。但是如果FreeLibrary（hDLLimp）被执行，我无法重复加载我的“implib.dll”。返回的hDLLimp为0。如果我评论FreeLibrary，加载函数可以重新执行几次。但保存功能不起作用。 hDLLexp变为“0”并且句柄消失。

    // Load function

HINSTANCE         hDLLimp = 0;
GETCOUNTS         fncgetcounts;
GETITEM           fncgetitem;
IMPEXPINTERFACE   fncimportinterface;
TProcLib          *proclib;
TNativeSurface    nativesurface;
char              filepath[_MAX_PATH];

hDLLimp = LoadLibrary(TEXT("implib.dll"));
DWORD Error = GetLastError();
if( hDLLimp == 0 )
{
    QMessageBox *msgBox = new QMessageBox;
    msgBox->setText("implib.dll konnte nicht geladen werden");
    msgBox->exec();
    return;
}

fncgetcounts = (GETCOUNTS) GetProcAddress(hDLLimp, "GetCounts");
fncgetitem = (GETITEM) GetProcAddress(hDLLimp, "GetItem");
fncimportinterface = (IMPEXPINTERFACE) GetProcAddress(hDLLimp, "ImportInterface");

for (long i=0; i<fncgetcounts()-1; i++) {
     if ((proclib = fncgetitem(i))==NULL) break;
     if (strcmp(proclib->ResName, "SDFIMPORT")==0) {
        strcpy(filepath, "test.sdf");
        fncimportinterface(filepath, _MAX_PATH, &(proclib->PrgId), 2, &nativesurface, 0, 0, NULL, NULL, 1); 
        break;
     }
  }
//FreeLibrary(hDLLimp);

    //Export/Save function

HINSTANCE         hDLLexp = 0;

GETCOUNTS         fncgetcounts;

GETITEM           fncgetitem;

IMPEXPINTERFACE   fncexportinterface;

TProcLib          *proclib;

TNativeSurface    nativesurface;

char              filepath[_MAX_PATH];

hDLLexp = LoadLibrary(TEXT("explib.dll"));
if( hDLLexp == 0 )
    {
        QMessageBox *msgBox = new QMessageBox;
        msgBox->setText("explib.dll konnte nicht geladen werden");
        msgBox->exec();
        return;
    }

    fncgetcounts = (GETCOUNTS) GetProcAddress(hDLLexp, "GetCounts");
    fncgetitem = (GETITEM) GetProcAddress(hDLLexp, "GetItem");
    fncexportinterface = (IMPEXPINTERFACE) GetProcAddress(hDLLexp, "ExportInterface");

    for (long i=0; i<fncgetcounts()-1; i++) {
         if ((proclib = fncgetitem(i))==NULL) break;
         if (strcmp(proclib->ResName, "SDFEXPORT")==0) {
            strcpy(filepath, "test.sdf");
            fncexportinterface(filepath, _MAX_PATH, &(proclib->PrgId), 2, &nativesurface, 0, 0, NULL, NULL, 1); 
            break;
         }
      }
    //FreeLibrary(hDLLexp);

显式DLL与C ++中的LoadLibrary和2个DLL链接

0 个答案: