为什么这样创建的一个新shape文件的字段与原有的Shape文件字段不同。

<P>Private Sub getNewFeatureClassByOld(ByVal pOldFeatureLayer As IFeatureLayer, ByVal pFeatureWorkspace As IFeatureWorkspace, _<BR>                                         ByVal pNewFileName As String)<BR>        Dim pNewFields As IFields<BR>        Dim pOldFeatureClass As IFeatureClass, pNewFeatureClass As IFeatureClass</P>
<P>        Dim pNewUID As UID, pNewExtUID As UID<BR>        Dim pNewFeatureType As esriFeatureType<BR>        Dim pNewShapefield As String</P>
<P>        Dim pNewIndex As Integer<BR>        pOldFeatureClass = pOldFeatureLayer.FeatureClass<BR>        pNewFields = pOldFeatureClass.Fields</P>
<P>        pNewUID = pOldFeatureClass.CLSID<BR>        pNewExtUID = pOldFeatureClass.EXTCLSID<BR>        pNewFeatureType = pOldFeatureClass.FeatureType<BR>        pNewShapefield = pOldFeatureClass.ShapeFieldName</P>
<P>        '创建一个要素类<BR>        pNewFeatureClass = pFeatureWorkspace.CreateFeatureClass(pNewFileName, pNewFields, pNewUID, pNewExtUID, pNewFeatureType, pNewShapefield, "") '（不含扩展名.shp）<BR>        If pNewFeatureClass Is Nothing Then<BR>            MsgBox("发生错误，程序退出!")<BR>            Exit Sub<BR>        End If<BR>end sub</P>
<P>我根据上面的方法创建一个新的shape文件，打开新创建的shape文件的字段表，发现与原来的字段定义有些不同，为什么？请大家帮忙看看</P>