得到选择的图块个数.

• 回答：

          using namespace MxDrawXLib;        void CTestDynCreateDlg::DoSelectBlk()
          {
              IMxDrawUtilityPtr utility;
              utility.CreateInstance(__uuidof( MxDrawUtility ));            if(utility == NULL)
              {                return;
              }
              
  
              _variant_t varPrompt;
              V_VT(&varPrompt)  = VT_BSTR;
              CString sPrompt;
              sPrompt.Format(_T("选择一个实体:"));
              V_BSTR(&varPrompt) = sPrompt.AllocSysString();
  
              _variant_t varSelPt;
              MxDrawXLib::IMxDrawEntityPtr spEnt =    utility->GetEntity(&varSelPt,varPrompt);            if(spEnt == NULL)                return;
  
              CString sName((const char*)(spEnt->ObjectName) );
  
              CComPtr<IMxDrawBlockReference> spBlk;
              spEnt->QueryInterface(&spBlk);            if(spBlk == NULL)
              {                return;
              }
  
              CString sBlkName = spBlk->GetBlockName();
  
              MxDrawXLib::IMxDrawSelectionSetPtr ssGet;
              ssGet.CreateInstance(__uuidof( MxDrawXLib::MxDrawSelectionSet ));            if(ssGet == NULL)
              {                return;
              }
  
              MxDrawXLib::IMxDrawResbufPtr filter;
              filter.CreateInstance(__uuidof( MxDrawXLib::MxDrawResbuf ));            // 设置图块
              filter->AddString(_T("INSERT"),5020);
              _bstr_t blkName((LPCTSTR)sBlkName);
              filter->AddString(blkName,2);
  
              std::auto_ptr<_variant_t> spVarPt1(new _variant_t);
              std::auto_ptr<_variant_t> spVarPt2(new _variant_t);
              ssGet->Select2(mcSelectionSetAll,*spVarPt1.get(),*spVarPt2.get(),NULL,filter);            if(ssGet->GetCount() == 0)                return;        //  for(long i = 0; i < ssGet->GetCount();i++)
          //  {
          //      MxDrawXLib::IMxDrawEntityPtr spEnt =  ssGet->Item(i);
          //      if(spEnt == NULL)
          //          continue;
          //  }
  
              CString sT;
              sT.Format(_T("发现了%d个"), ssGet->GetCount());
              AfxMessageBox(sT);
          }