用VBA,想看Raster有几个bands，为什么下面的代码会出错

<P>Public Sub checknumber()</P>
<P>Dim pMap As IMap<br>Dim pMxDocument As IMxDocument<br>Set pMxDocument = ThisDocument<br>Set pMap = pMxDocument.FocusMap</P>
<P>Dim pRasterlayer As Irasterlayer<br>Set pRasterlayer = pMap.Layer</P>
<P>Dim pRaster As IRaster<br>Set pRaster = pRasterlayer.Raster</P>
<P>Dim pRasBC As IRasterBandCollection<br>Set pRasBC = pRaster<br>MsgBox "Number of bands in Raster:" ; CInt(pRasBC.Count)</P>
<P>End Sub</P>
<P>运行后出现compile error:argument not optional的错误，然后指向了Public Sub Checknumber()，请问这个代码有什么问题？？</P>

<P>搞定了，是因为Set pRasterlayer = pMap.Layer应该改成pMap.layer(0)</P>