代码如下，只要是datalayer就行，featurelayer、tin、raster等都可以获得 

 ''' <summary>
  ''' 获得datalayer所对应的文件路径
  ''' </summary>
  ''' <param name="pDataLayer">图层</param>
  ''' <param name="pFilePath">文件路径</param>
  ''' <param name="pFileName">文件名</param>
  ''' <remarks></remarks>
  Public Sub GetDataLayerPath(ByVal pDataLayer As IDataLayer, ByRef pFilePath As String, ByRef pFileName As String)
    Dim pDatasetName As IDatasetName
    Dim pWSName As IWorkspaceName

    pDatasetName = pDataLayer.DataSourceName
    pWSName = pDatasetName.WorkspaceName
    pFilePath = pWSName.PathName
    pFileName = pDatasetName.Name
  End Sub