build temporary list

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ASKER

Cool - let me try to work this out based upone the ideas you've presented...I'll let you know. Thanx!

ASKER

Here's what I've come up with - though I'm hitting my 'favorite' error again where noted:

Private Function Scanit(ByVal pFolder As String) As DataSet
Dim strPath As String = System.AppDomain.CurrentDomain.BaseDirectory
Dim arrFileTypes() As String, ext As String, x As Int16
arrFileTypes = Split("ASF,AVI,BMP,EXE,JPG,MDB,PST,ZIP", ",")
Dim strtDT As DateTime = DateTime.Now
Dim dtExt As DataTable = New DataTable
Dim FileName As New DataColumn, FileSize As New DataColumn, CreationDate As New DataColumn
Dim LastAccessed As New DataColumn, LastWritten As New DataColumn, FileType As New DataColumn
Dim dr As DataRow = Nothing
With dtExt.Columns
.Add(FileName)
.Add(FileSize)
.Add(CreationDate)
.Add(LastAccessed)
.Add(LastWritten)
.Add(FileType)
End With
Dim d() As String = Nothing
Try
d = Directory.GetFiles(pFolder, "*.*", SearchOption.AllDirectories)
Catch ex As Exception
MessageBox.Show(Err.Description)
End Try

Dim en As Collections.IEnumerator
Dim fileInfo As FileInfo
en = d.GetEnumerator
While en.MoveNext
x += 1
For Each ext In arrFileTypes
If UCase(en.Current.ToString.Substring(Len(en.Current) - 3)) = ext Then
Try
fileInfo = New FileInfo(en.Current)
With dr
.Item(0) = Replace(en.Current, pFolder, "") <=======object reference not set to instance...
.Item(1) = fileInfo.Length
.Item(2) = fileInfo.CreationTime.Date
.Item(3) = fileInfo.LastAccessTime.Date
.Item(4) = fileInfo.LastWriteTime.Date
.Item(5) = ext
End With
Catch ex As Exception
MessageBox.Show(Err.Description)
End Try
End If
Next
End While
Dim dsScan As New DataSet
dsScan.Tables.Add(dtExt)
Return dsScan

Dim dr As DataRow = Nothing
'[...]
With dr
.Item(0) = Replace(en.Current, pFolder, "") <=======object reference not set to instance...

Do you wonder?

What happened to

Dim dr As DataRow = FileTable.NewRow
'[...]
FileTable.Rows.Add(dr)

from the sample code?

So far as I can see, it should work with that amendment.

Two thoughts, though. Depending on precisely how you subsequently need to use the data, you might have later problems having left all columns' datatypes as the default (which is string). And I wonder why you get your function to return a dataset, into which you put the datatable you have created, rather than just returning the datatable itself. Datatables don't have to go in Datasets to be usable, and I can see no good reason for putting this in one.

Roger

I say cant beat good old collections. You can add any object (like a Fileinfo class) you like to a collection and ctype it back on the way out.

Much simpler but i suppose it all depends on what you want to do with it *afterwards*...

ASKER

So, I should just return the table?
I did a little searching afterwards and mimiced 'that' code, as I initially had problems with the .NewRow being 'recognized' (it's working now, however).

lojk - I'm not sure what you mean by using collections - that's a bit outside my current skillset, I'm afraid.

ASKER

Okay - the table was built - I saw it process at least 1 row, but the returned table's count property is 0.
How do I access the rows to read them?

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ASKER

>>Assuming that its signature has been changed to read
Private Function Scanit(ByVal pFolder As String) As DataTable <<

it has

>>and the line at the end has been changed to
Return dtExt<<

it has

>>the calling code should be something like
Dim FileTable As DataTable = Scanit(<mypath>)<<

Currently it's:
Dim dtScan As DataTable
dtScan = Scanit(strShare)

Then I have

For Each dr As DataRow In dtScan.Rows
Dim FilePath As String = dr(0)
Dim FileSize As String = dr(1)
Dim FileCreation As String = dr(2)
Dim FileAccess As String = dr(3)
Dim FileModify As String = dr(4)
Dim FileExt As String = dr(5)
Next

but, the 'count' still comes back as 0 (when it's not) and it skips this for loop...

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ASKER

msgbox(dtScan) already says 'datatable cannot be converted to string'

ASKER

but even the first is 0, so that would be 'why'...
Now 'why' isn't it getting into the table? Hmm...

My fault. I meant

msgbox(dtScan.Rows.Count)

Roger

My guess is that this line

FileTable.Rows.Add(dr)

or the equivalent in your terminology, is missing.

Roger

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ASKER

Roger -
where should
dtExt.Rows.Add(dr)
be placed?
I'm getting an error "this row already belongs to this table"

ASKER

working now...

ASKER

I adjusted the following:

Try
fileInfo = New FileInfo(en.Current)
Dim dr As DataRow = dtExt.Rows.Add

and it's working now.

OK, if you've sorted it

But what you had was

Dim en As Collections.IEnumerator
Dim fileInfo As FileInfo
en = d.GetEnumerator
While en.MoveNext
x += 1
For Each ext In arrFileTypes
If UCase(en.Current.ToString.Substring(Len(en.Current) - 3)) = ext Then
Try
fileInfo = New FileInfo(en.Current)
With dr
.Item(0) = Replace(en.Current, pFolder, "") <=======object reference not set to instance...
.Item(1) = fileInfo.Length
.Item(2) = fileInfo.CreationTime.Date
.Item(3) = fileInfo.LastAccessTime.Date
.Item(4) = fileInfo.LastWriteTime.Date
.Item(5) = ext
End With
Catch ex As Exception
MessageBox.Show(Err.Description)
End Try
End If
Next
End While

What I'd given you was

Dim dr As DataRow = FileTable.NewRow '<<< THIS LINE WAS MISSING
dr("Path") = <thisPath>
dr("FileType") = <thisFileType>
dr("FileSize") = <thisFileSize>
'etc
FileTable.Rows.Add(dr) '<<< THIS LINE WAS MISSING

Your code, to be equivalent to mine, should have been

Dim dr As DataRow = dtExt.NewRow
With dr
.Item(0) = Replace(en.Current, pFolder, "") <=======object reference not set to instance...
.Item(1) = fileInfo.Length
.Item(2) = fileInfo.CreationTime.Date
.Item(3) = fileInfo.LastAccessTime.Date
.Item(4) = fileInfo.LastWriteTime.Date
.Item(5) = ext
End With
dtExt.Rows.Add(dr)

Incidentally, (1) I'm not sure how the code you put in your last post would make anything work

Dim dr As DataRow = dtExt.Rows.Add

doesn't look like a valid statement to me. And (2) lojk has a good point. I offered you a datatable as your temporary array as I know you're getting used to working with them. But there's all sorts of other mainfestations of Collections which would be just as good - or for many purposes, better.

Still, so long as you're happy ;-) Thanks for the points.

Roger

The old KISS principle always applies especially in VB (c# forces you by its syntax to be a little more explicit sometimes).

I suppose it depends for what you are writing the code. For my home/personal projects I am a total Purist, prefering long winded and strongly typed code where possible but in commercial development, whatever works quickly and simply is what i tend to end up doing. (Perhaps thats why none of my home projects never get finsihed!).

Thanks for points BTW

ASKER

I liked the idea lojk - but since I felt the momentum with the datatable, and as Roger pointed out, have been becoming more familiar with them, went more in that direction.
Perhaps not the best route, but so far so good...it's working.

Thanx to you both.

Hey, cool. As long as your code is broken down into manageable sized blocks you can always come back later and refactor it without affecting other code. Only really wanted to give you another option because as im sure you are realising there is ALWAYS more than one way to do these things.

:-)