新建ECShema,ImportSchema调试出错

我新建一个ECSchema,并新建一个ECClass,添加两个属性,然后我用ImportSchema导入到dgn出错,

dgnOpenStatus值是DGNOPEN_STATUS_UnrecognizedFormat,为什么呢,老师们能帮我解答下吗?

代码如下:
 

DgnFilePtr    openForWrite(WString filename, DgnFileOpenMode mode)
{
 DgnDocumentPtr dgnDoc = DgnDocument::CreateForLocalFile(filename.c_str());
 RefCountedPtr<DgnFile> dgnFile = DgnFile::Create(*dgnDoc, mode);
 StatusInt                   openForWriteStatus;
 DgnPlatform::DgnFileStatus  dgnOpenStatus = dgnFile->LoadDgnFile(&openForWriteStatus);
 if (DGNFILE_STATUS_Success != dgnOpenStatus)
  return NULL;
 dgnFile->FillDictionaryModel();
 return dgnFile;
}


void newECClass(WCharCP unused)
{
 WCharCP stringP = L"新建ECClass测试!";
 mdlDialog_openInfoBox(stringP);


 //新建一个ECClass
 DgnFilePtr dgnFile = openForWrite(gOptions.fileName, DgnFileOpenMode::ReadWrite);
 if (dgnFile.IsValid())
 {
  DgnECManagerR dgnECManager = DgnECManager::GetManager();
  ECN::ECSchemaPtr pSchema;
  WCharCP schemaName = L"schema_zqh";
  dgnECManager.CreateSchema(pSchema, schemaName, 1, 0, dgnFile.get());

  ECN::ECSchema *schemaP = pSchema.get();
  WString name = schemaP->GetName();
  ECN::SchemaKey ss = schemaP->GetSchemaKey();
  ECClassP zqhClass;
  WString className = L"zqhClassName";
  schemaP->CreateClass(zqhClass, className);

  //ECProperty  StructECProperty PrimitiveECProperty
  PrimitiveECPropertyP ecpProperty;
  WString priProName = L"priProName";
  StructECPropertyP ecsProperty;
  WString struProName = L"struProName";
  zqhClass->CreatePrimitiveProperty(ecpProperty, priProName);
  zqhClass->CreateStructProperty(ecsProperty, struProName);
  dgnECManager.UpdateSchema(*pSchema, *dgnFile, false);
  dgnECManager.ImportSchema(*pSchema, *dgnFile, false, true);
 }
}