[求助]：BlockTable遍历失败

2323220987

我想遍历打开文件中的实体，程序如下：es =pBlockTableRecord4->newIterator(pIter); 运行到这句就报错，unhandled exception 之类的，这段代码我原来在2002上用没问题的。大家有遇到这种问题吗？我的编程环境：vs2005+autocad2007+objectarx2007.而且我把代码中的遍历类型换成层遍历，又可以正常运行，挺奇怪的。

AcDbDatabase *pCurDb = NULL;
  Acad::ErrorStatus es;
int i;
AcDbBlockTable *pBlockTable4;

acDocManager->lockDocument( acDocManager->curDocument(), AcAp::kWrite, NULL, NULL,true) ;

pCurDb = acdbHostApplicationServices()->workingDatabase();
    es =pCurDb->getSymbolTable(pBlockTable4, AcDb::kForRead);//
if (es != Acad::eOk) {
acutPrintf(_T("\ngetSymbolTable!"));
        }
acutPrintf(_T("\n2!"));
    AcDbBlockTableRecord *pBlockTableRecord4;
    es =pBlockTable4->getAt(ACDB_MODEL_SPACE, pBlockTableRecord4,AcDb::kForWrite);
if (es != Acad::eOk) {
acutPrintf(_T("\ngetAt!"));
        }
acutPrintf(_T("\n3!"));
   
AcDbBlockTableRecordIterator *pIter;
  //AcDbBlockTableRecordPointer pBTR(ACDB_MODEL_SPACE,acdbHostApplicationServices()->workingDatabase(),AcDb::kForRead);

es =pBlockTableRecord4->newIterator(pIter);  //获得遍历指针,true,true
acutPrintf(_T("\n5!"));
        if (es != Acad::eOk) {
       acutPrintf(_T("\ngetAt!"));
        }