大家帮一下忙，这到底是怎么回事？

[geniusdhc]

我写了一个dll(比如aa.dll)，每当主程序project1.exe执行到LoadLibrary("aa.dll");的时候，弹出错误：Project project1.exe raised exeception class EFilterError with message 'A class named TdxTreeListColumn already exists'.
点击‘确定‘按钮后， 又出现 Project project1.exe raised exeception class EStackOverflow with message 'Stack overflow'.

请问这是怎么回事？先谢谢大家。

[劣势]

代码贴出来吧，提示的含义是栈溢出

[geniusdhc]

if( NULL == DLLInst )
DLLInst = LoadLibrary("topodll.dll"); //就是在这行上出错
if (DLLInst)
{
CreateFromFunct = (void (__stdcall*)()) GetProcAddress(DLLInst, "UpdateTopo_XLT");
if (CreateFromFunct)
CreateFromFunct();
else
ShowMessage("Could not obtain function pointer");
}
else ShowMessage("Could not load DLL.dll");


下面是要调用的函数
extern "C" void __declspec(dllexport) __stdcall ShowTopo(AnsiString objectid,TForm* parentform,TTreeView* ObjectTreeView,TList* vMenuList)
{
for(int i=(parentform->MDIChildCount-1);i>=0 ;i--)
{
if(parentform->MDIChildren[i]->Name.Pos("frmTopoLayer")>0)
{
if(((TfrmTopoLayer*)parentform->MDIChildren[i])->root_maplayer_id==AnsiString(objectid))
{
parentform->MDIChildren[i]->BringToFront();
return;
}
}
}

if(objectid != NULL)
{
TTreeView* view;
view = (TTreeView*)ObjectTreeView;
///////如果把下面几行注释掉旧不会有问题。
TfrmTopoLayer *frmTopoLayer = new TfrmTopoLayer(NULL);
frmTopoLayer->setMaplayerParam("90", objectid,vMenuList,view->Selected->Text);
frmTopoLayer->Show();
if(frmTopoLayer!= NULL)
{
delete frmTopoLayer;
frmTopoLayer = NULL;
}
///////注释范围end
}
}