ItemCommand Not Firing with ImageButton

CSharpJunkie

OK I was just about to post a question on here, and I went to check one more thing before posting it. I got it to work. BUT, I still want to know why it didnt work the other way. I have a DataList for a menu. I have plus and minus gifs that expand and collapse when clicked. When these gifs were rendered using ImageButton, they would not fire the ItemCommand event for the DataGrid. I then Changed them to LinkButtons, with a basic image tag for the text, and the event fires....WHY? Here is the code for the scenario that did NOT work. (Using the ImageButton) '********************************************************* '***************** THIS CHANGED************************ '****************************************************** .....HTML Table removed Here...... to keep it simple, this was just the department names, and category names with category names indented to show they resided under Departments ***** The code Behind for the ItemCommand Event That did NOT work Looked like this.... Public Sub DataGrid1_ItemCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataGridCommandEventArgs) Handles DataGrid1.ItemCommand '*********************THIS CHANGED *********************** If CType(e.Item.Cells(0).FindControl("img"), ImageButton).ImageUrl.EndsWith("closed.gif") Then '******************************************************* ' condition for node opening Dim i As Integer = 1 Dim Root As System.Int64 = Convert.ToInt64(DataGrid1.Items(e.Item.ItemIndex).Cells(1).Text()) Dim img As ImageButton For i = 1 To DataGrid1.Items.Count - 1 If (CInt(DataGrid1.Items(i).Cells(1).Text) = Root) Then 'This is a department DataGrid1.Items(i).Visible = True End If If CType(DataGrid1.Items(i).Cells(2).Text, Integer) > 0 Then DataGrid1.Items(i).Cells(0).Controls.Clear() DataGri

minhpc_bk

Hi Shawn, Have you tried to run your application in debug mode to see if the ItemCommand event gets fired when you place an ImageButton in a template column? Basically, in addition to the predefined buttons such as edit, delete, update ..., the Click event of the Button/LinkButton/ImageButton controls will be bubbled up to the ItemCommand event when they are placed inside a datagrid (also with datalist and repeater) control.

Shawn_H

minhpc, Yes, I did set a break point and ran the app in debug mode. The ItemCommand Event never fired when the ImageButton was in the column, But then when I changed it to a LinkButton, it fired. Im fairly new to ASP.NET, so I was just wondering why the LinkButton fired this event, but not the ImageButton. I put both versions of code in the starter thread, could you see why the ImageButton wouldnt fire? Thanks Shawn

minhpc_bk

Shawn, The datagrid control (after looking at your sample code) looks fine to me except the spelling error aps. May I suggest you to comment out all the source code in the ItemCommand event handler and simply put a simple call to Response.Write method? What I want to do here is to try to play around with the ImageButton in a very simple case and see if the ItemCommand event gets fired. Another way is to check if the Click event of the ImageButton gets fired.

Shawn_H

minhpc, Yeah, That spelling error was not in the original code, but was done after I posted it into the code project form (as I was trying to format in order to make it more readable.) I did have break points set though, with all the code commented out of the event except for a simple If 1=1 Then Dim str As string = "Hello" and it never fired..... I dont know what it was, it was something weird though...no big deal, thanks for looking at it though Shawn

minhpc_bk

Hi Shawn, I'm sorry when I can't help you figure out the cause. Anyway, if you have time, you might want to try with the sample code below which demonstrates the use of the ImageButton control in a template column. Hopefully, you can find a hint in your sample code:

<%@ Page Language="vb"%>
<%@ Import Namespace="System.Data"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<title>WebForm1</title>
<script runat="server" language="vb">
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs)
If Not IsPostBack Then
BindGrid()
End If
End Sub

Public Sub BindGrid()
    Dim objConn As New System.Data.SqlClient.SqlConnection("server=localhost;uid=sa;pwd=;database=Northwind;Timeout=600;")
    objConn.Open()
               
    Dim strSQL As String
    Dim objDataset As New DataSet
    Dim objAdapter As New System.Data.SqlClient.SqlDataAdapter
                
    strSQL = "Select \* from customers"
    objAdapter.SelectCommand = New System.Data.SqlClient.SqlCommand(strSQL, objConn)
    objAdapter.Fill(objDataset)
                  
    DataGrid1.DataSource = objDataset
    DataGrid1.DataBind()
End Sub
               
Public Sub DataGrid1\_ItemCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataGridCommandEventArgs)

    Response.Write("DataGrid1\_ItemCommand : " + e.CommandSource.GetType().ToString())
End Sub
</script>

</head>
<body MS_POSITIONING="GridLayout">
<form id="Form1" method="post" runat="server">
<asp:DataGrid id="DataGrid1" style="Z-INDEX: 101; LEFT: 264px; POSITION: absolute; TOP: 112px"
runat="server" AutoGenerateColumns="False" OnItemCommand="DataGrid1_ItemCommand">
<Columns>
<asp:TemplateColumn ItemStyle-Height="20px" ItemStyle-Width="5px">
<ItemTemplate>
<asp:ImageButton ID="img" ImageUrl="images/plus_open.gif" CommandName="imgclick"
Runat="server"></asp:ImageButton>
</ItemTemplate>
</asp:TemplateColumn>
<asp:BoundColumn DataField="CustomerID" HeaderText="CustomerID"></asp:BoundColumn>
<asp:BoundColumn DataField="CompanyName" HeaderText="CompanyName"></asp:BoundColumn>
</Columns>
</asp:DataGrid>
</form>