problem with connecting gridview with data in code-behind

[Dan]

Hi,

i defined a gridview in aspx file and i try to connect it to a datasource in
code-behind (vb.net).
i know there are records (tested with response.write).
The problem is that the gridview remains invisible because no records come
into it.
Here is the code:
Thanks
Dan

code in aspx file
----------------
<asp:GridView ID="GridView1" runat="server" >
</asp:GridView>


code-behind
-------------
Dim bf As New BoundField
Dim dtreader As SqlDataReader
.....
.....
comd.CommandText = "select email from email"
dtreader = comd.ExecuteReader
If dtreader.HasRows Then
While dtreader.Read()
dtreader.GetString(0)
'tested with response.write
End While
End If
bf.DataField = "email"
bf.HeaderText = "email"
GridView1.Columns.Add(bf)
GridView1.DataSource = dtreader
GridView1.DataBind()

 

[sloan]

An IDataReader is a firehose method for dataaccess. Once the firehose is
"rolled out", you're at the end of it.

Once you run this:
If dtreader.HasRows Then
While dtreader.Read()
dtreader.GetString(0)
'tested with response.write
End While
End If

the firehose is at end..........that's why your next lines of binding don't
work.


As a test, get rid of this code:
If dtreader.HasRows Then
While dtreader.Read()
dtreader.GetString(0)
'tested with response.write
End While
End If


and ~~then~~ bind.


You might want to google
N Layered Development

Because that code is deficient when it comes to best practices.

 

[Dan]

thanks

An IDataReader is a firehose method for dataaccess. Once the firehose is
"rolled out", you're at the end of it.

Once you run this:
If dtreader.HasRows Then
While dtreader.Read()
dtreader.GetString(0)
'tested with response.write
End While
End If

the firehose is at end..........that's why your next lines of binding
don't work.


As a test, get rid of this code:
If dtreader.HasRows Then
While dtreader.Read()
dtreader.GetString(0)
'tested with response.write
End While
End If


and ~~then~~ bind.


You might want to google
N Layered Development

Because that code is deficient when it comes to best practices.