vc Variant类型转换成CString函数

CString CZjyDlg::VariantToString(VARIANT var)
{
CString strValue;
         _variant_t var_t;
         _bstr_t bstr_t;
         time_t cur_time;
         CTime time_value;
         COleCurrency var_currency;
         switch(var.vt)
         {
         case VT_EMPTY:
         case VT_NULL:strValue=_T("");break;
         case VT_UI1:strValue.Format("%d",var.bVal);break;
         case VT_I2:strValue.Format("%d",var.iVal);break;
         case VT_I4:strValue.Format("%d",var.lVal);break;
         case VT_R4:strValue.Format("%f",var.fltVal);break;
         case VT_R8:strValue.Format("%f",var.dblVal);break;
         case VT_CY:
                   var_currency=var;
                   strValue=var_currency.Format(0);break;
         case VT_BSTR:
                   var_t =var;
                   bstr_t=var_t;
                   strValue.Format("%s",(const char *)bstr_t);break;
         case VT_DATE:
                   cur_time=var.date;
                   time_value=cur_time;
                   strValue.Format("%A,%B,%d,%Y");break;
         case VT_BOOL:strValue.Format("%d",var.boolVal);break;
         default:strValue=_T("");break;