Databinding by ClientID

**Mike Moore [MSFT]** · Nov 17 '05, 10:36 PM

RE: Databinding by ClientID

Hi Oafyuf,

You need to use the datagrid's ItemDataBound event to populate the inner
datalist. Here is a sample based on the Pubs sample database.

I placed a datagrid on a form and added a template column (the rest are
autogenerate). I added a datalist to the template column. Then I added the
following code.

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load
If Not IsPostBack Then
Bind()
End If
End Sub

Private Sub Bind()
Dim Qry1 As System.Data.Sql Client.SqlDataR eader
Dim connectionStrin g As String = "server='localh ost';
trusted_connect ion=true; Database='pubs' "
Dim sqlConnection As System.Data.Sql Client.SqlConne ction = New
System.Data.Sql Client.SqlConne ction(connectio nString)
Dim queryString As String = "SELECT au_id, au_lname, au_fname FROM
authors"
Dim sqlCommand As System.Data.Sql Client.SqlComma nd = New
System.Data.Sql Client.SqlComma nd(queryString, sqlConnection)
sqlConnection.O pen()
Qry1 =
sqlCommand.Exec uteReader(Syste m.Data.CommandB ehavior.CloseCo nnection)
DataGrid1.DataS ource = Qry1
DataGrid1.DataB ind()
Qry1.Close()
sqlCommand.Disp ose()
sqlConnection.C lose()
sqlConnection.D ispose()
End Sub

Private Sub DataGrid1_ItemD ataBound(ByVal sender As Object, ByVal e As
System.Web.UI.W ebControls.Data GridItemEventAr gs) Handles
DataGrid1.ItemD ataBound
If e.Item.ItemType = ListItemType.It em Or e.Item.ItemType =
ListItemType.Al ternatingItem Then
Dim list As ListBox
list = e.Item.Cells(0) .Controls(1)
Dim Qry1 As System.Data.Sql Client.SqlDataR eader
Dim connectionStrin g As String = "server='localh ost';
trusted_connect ion=true; Database='pubs' "
Dim sqlConnection As System.Data.Sql Client.SqlConne ction = New
System.Data.Sql Client.SqlConne ction(connectio nString)
Dim queryString As String = "SELECT title FROM titles t inner
join titleauthor ta on t.title_id = ta.title_id inner join authors a on
ta.au_id = a.au_id where a.au_id = '" & e.Item.Cells(1) .Text & "'"
Dim sqlCommand As System.Data.Sql Client.SqlComma nd = New
System.Data.Sql Client.SqlComma nd(queryString, sqlConnection)
sqlConnection.O pen()
Qry1 =
sqlCommand.Exec uteReader(Syste m.Data.CommandB ehavior.CloseCo nnection)
list.DataSource = Qry1
list.DataTextFi eld = "title"
list.DataBind()
If list.Items.Coun t = 0 Then list.Visible = False
list.Height = list.Height.Poi nt(30 * list.Items.Coun t)
Qry1.Close()
sqlCommand.Disp ose()
sqlConnection.C lose()
sqlConnection.D ispose()
End If
End Sub

---
I hope this helps.

Thank you, Mike
Microsoft, ASP.NET Support Professional

Microsoft highly recommends to all of our customers that they visit the
http://www.microsoft.com/protect site and perform the three straightforward
steps listed to improve your computer’s security.

This posting is provided "AS IS", with no warranties, and confers no rights.

--------------------[color=blue]
> From: oafyuf@hotmail. com (oafyuf)
> Newsgroups: microsoft.publi c.dotnet.framew ork.aspnet
> Subject: Databinding by ClientID
> Date: 24 Oct 2003 04:24:41 -0700
> Organization: http://groups.google.com
> Lines: 138
> Message-ID: <ea81924d.03102 40324.64785c22@ posting.google. com>
> NNTP-Posting-Host: 212.137.57.41
> Content-Type: text/plain; charset=ISO-8859-1
> Content-Transfer-Encoding: 8bit
> X-Trace: posting.google. com 1066994681 30561 127.0.0.1 (24 Oct 2003[/color]
11:24:41 GMT)[color=blue]
> X-Complaints-To: groups-abuse@google.co m
> NNTP-Posting-Date: Fri, 24 Oct 2003 11:24:41 +0000 (UTC)
> Path:[/color]
cpmsftngxa06.ph x.gbl!TK2MSFTNG P08.phx.gbl!new sfeed00.sul.t-online.de!t-onlin
e.de!news-spur1.maxwell.s yr.edu!news.max well.syr.edu!po stnews1.google. com!no
t-for-mail[color=blue]
> Xref: cpmsftngxa06.ph x.gbl microsoft.publi c.dotnet.framew ork.aspnet:1862 90
> X-Tomcat-NG: microsoft.publi c.dotnet.framew ork.aspnet
>
> Hi,
> I'm trying to learn ASP.NET by doing a pilot project:
>
> I have a DataGrid which contains a nested DataList. I want to iterate
> through the SQLDataReader for the DataGrid and populate each DataList
> by binding to a fresh SQLDataReader. At the moment I can only bind to
> the first instance of the DataList. If I could bind the data by the
> ClientID (or UniqueID), I'm sure it would work. Is there a way of
> doing this? Or maybe there is a better approach to getting nested data
> from separate SQLDataReaders.
>
> Here's the relevant part of the code with extraneous bits removed (I
> hope the line breaks don't make it unreadable!):
>
> // ######### ASPX ###########
>
> <asp:DataGrid Border="1" Runat="server" Id="dgApplicant s">
> <Columns>
> <asp:BoundColum n DataField="Appl icantRef" Visible="False" />
>
> <%-- Some more BoundColumns and TemplateColumns --%>
>
> <asp:TemplateCo lumn>
> <ItemTemplate >
> <tr>
> <td width="30px">&n bsp;</td>
> <td colspan="8">
> <asp:DataList Border="0" Runat="server" Id="dgApplicati ons"
> AutoGenerateCol umns="False" Height="0px" Width="100%"
> AllowSorting="F alse">
> <ItemTemplate >
> App < %# DataBinder.Eval (Container.Data Item,
> "VendorNo")%>&n bsp;<%# DataBinder.Eval (Container.Data Item,
> "ApplicationRef ")%> v <%# DataBinder.Eval (Container.Data Item,
> "Version")%>&nb sp;<%# DataBinder.Eval (Container.Data Item,
> "Status")%> 
> </ItemTemplate>
> </asp:DataList>
> </td>
> </tr>
> </ItemTemplate>
> </asp:TemplateCol umn>
> </Columns>
> </asp:DataGrid>
>
> // ######### ASPX ENDS ###########
>
> // ######### CODE-BEHIND ###########
> //adoApplicantRea der is the outer loop
> //adoApplicationR eader is the inner loop
>
> if(objDuplicate PartiesApplican t.ListParties(i nputSurname, inputTown,
> inputMainCPH, inputBusinessNa me, inputPostcode, inputOrderBy, ref
> adoApplicantRea der) == MyAssembly.AESI S.ReturnCodes.S uccess)
> {
> // OK, the SQL data layer object returned "success", but did we get
> some results?
> if(adoApplicant Reader.HasRows)
> {
> // successful search: hide prompt and display Update button
> lblPrompt.Visib le = false;
> btnUpdate.Visib le = true;
>
> // databinding method
> this.dgApplican ts.DataSource = adoApplicantRea der;
> this.dgApplican ts.DataBind();
> adoApplicantRea der.Close();
>
> // with the firehose cursor (SQLDataReader) , we have to do the query
> again after it is bound to pass it's members...
> if(objDuplicate PartiesApplican t.ListParties(i nputSurname, inputTown,
> inputMainCPH, inputBusinessNa me, inputPostcode, inputOrderBy, ref
> adoApplicantRea der) == MyAssembly.AESI S.ReturnCodes.S uccess)
> {
> // SQL data layer object returned "success"
> if(adoApplicant Reader.HasRows)
> {
> while (adoApplicantRe ader.Read())
> {
> int intOrd = adoApplicantRea der.GetOrdinal( "ApplicantRef") ;
> int intApplicantRef = (int)adoApplica ntReader.GetVal ue(intOrd);
>
> SqlDataReader adoApplicationR eader = null;
>
>[/color]
if(objDuplicate PartiesApplicat ion.ListPartyAp plications(intA pplicantRef,[color=blue]
> ref adoApplicationR eader) == MyAssembly.AESI S.ReturnCodes.S uccess)
> {
> // did we get some results?
> if(adoApplicati onReader.HasRow s)
> {
> // find a reference to the nested DataList
> foreach(DataGri dItem dgItem in dgApplicants.It ems)
> {
>
> DataList dgSelected =
> (DataList)dgIte m.FindControl(" dgApplications" );
>
> // here I need to find the reference name of each nested
> datagrid
> // and assign data to that...
> Response.Write( "<tr><td><f ont color=#cc0000>C lientID:
> "+dgSelected.Cl ientID+"</td></tr>"); // debug
> dgSelected.Data Source = adoApplicationR eader;
> dgSelected.Data Bind();
>
> }
> }
> adoApplicationR eader.Close();
> }
> }
> }
> }
> else
> {
> lblPrompt.Text = "No records returned for this search. Please try
> again.";
> }
> // tidy up before the garbage collector gets a chance to do it...
> adoApplicantRea der.Close();
> }
> else
> {
> lblPrompt.Text = "DATABASE ERROR: \ "" +
> objDuplicatePar tiesApplicant.N ativeError + "\" Please
> report this error to AESIS support.";
> }
> }
> // ######### CODE-BEHIND ENDS ###########
>
> The whole thing looks ugly to me because I have to keep on getting
> fresh data, is there a more flexible cursor that I can use?
>
> My next step is to investigate using DataSets, combining the XML DOMs
> and doing all the manipulation of the presentation layer via
> client-side JavaScript. Is this the recommended method?
>
> Thanks,
> oafyuf
>[/color]

Databinding by ClientID

Databinding by ClientID

Comment