LinkButton in Datalist to delete...verify first?[RESOLVED]

[brendalisalowe]

I have a datalist and I have a LinkButton to delete. This is my code behind that:

Sub DataList_DeleteCommand(ByVal sender As Object, ByVal e As DataListCommandEventArgs)
        Dim conn As SqlConnection = New SqlConnection(ConfigurationSettings.AppSettings().Item("strConn"))
 
        Dim acctno As String = DataList1.DataKeys(e.Item.ItemIndex)
 
        Dim sql As String = "DELETE FROM CustomerRecords " & _
                            "WHERE ConsumerAccountNumber = '" & acctno & "'"
 
        Dim cmd As New SqlCommand(sql, conn)
        Try
            conn.Open()
            cmd.ExecuteNonQuery()
        Catch ex As Exception
            Response.Write(ex.Message)
        Finally
            If Not conn Is Nothing Then
                conn.Dispose()
            End If
        End Try
        DataList1.EditItemIndex = -1
        DataBinder()
    End Sub

I was just wondering if there is a way to have a MessageBox pop saying "Do you want to do this: Yes or No"?

I'm assuming JavaScript or something maybe? let me know. Thanks!

[dj4uk]

Show us how your DataList is bound to your data source plus the where the delete button is created.

Basically you add the JavaScript code like so:

deleteButton.Attributes["OnClick"] = "javascript:return confirm('Are you sure you want to delete this gallery entry?')";

However where you do this depends on how you create the delete button.

DJ

[brendalisalowe]

Here is part of my datalist where the delete linkbutton is located. Does that help?


<ITEMTEMPLATE>
<TABLE width="100%"> <TR>
<TD width="9%">
<asp:LinkButton id="lnkEdit" runat="server" CommandName="edit" Text="Edit"></asp:LinkButton></TD>
<TD width="9%">
<asp:LinkButton id="lnkDelete" runat="server" CommandName="delete" Text="Delete"></asp:LinkButton></TD>
</TR>
</TABLE>
</ITEMTEMPLATE>

[dj4uk]

Yep you need to add the client-side onclick attribute in the DataList's ItemDataBound event.

    void DataList1_ItemDataBound( object s, DataListItemEventArgs e ) {
        if ( e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem ) {
            LinkButton deleteButton = (LinkButton) e.Item.FindControl("lnkDelete");
    
            deleteButton.Attributes["onclick"] = "javascript:return confirm('Are you sure you want to delete this?')";
        }
    }

You also need to add to your existing DataList tag the following to ensure the above method is called:

<asp:DataList id="DataList1" OnItemDataBound="DataList1_ItemDataBound">

Basically what this does is when the DataList is populated it checks all ItemTypes of Item and AlternatingItem for a control with the id lnkDelete and then adds a client-side event to it. You need to check the ItemType as your DataList's Header, Footer and Separators don't contain this delete button.

Sorry the code is in C# but my VB.NET ain't too hot.

Let me know if anything isn't clear.

DJ

[brendalisalowe]

So I don't put the above code inside this:

Sub DataList_DeleteCommand(ByVal sender As Object, ByVal e As DataListCommandEventArgs)
End Sub

And I've tried this but it doesn't work. Is it set up right?

Sub DataList1_ItemDataBound(ByVal sender As Object, ByVal e As DataListCommandEventArgs) 'Is this part right?
        If (e.Item.ItemType = ListItemType.Item And e.Item.ItemType = ListItemType.AlternatingItem) Then
            Dim deleteButton As LinkButton = e.Item.FindControl("lnkDelete")
            deleteButton.Attributes("OnClick") = "javascript:return confirm('Are you sure you want to delete this entry?')"
        End If
    End Sub

Also, I am not hot in C# so can anyone else help me out with that? Thanks!

[dj4uk]

No you still need the DeleteCommand server-side event to actually delete whatever you need to - the method I posted was just to add a client-side JavaScript "are you sure?" message box. That cannot be done server-side so you must attach a client-side event as I have described in the ItemDataBound event.

I'll have a go at converting! Unless anyone else beats me to it.

DJ

[dj4uk]

Actually I think you converted it ok now I've read it. Let me know if it works!

DJ

[dj4uk]

Did you add the OnItemDataBound="DataList1_ItemDataBound" to the DataList tag?

DJ

[brendalisalowe]

But does || mean AND or OR?

[dj4uk]

Actually it should be an Or not an And in the if statement.

DJ

[brendalisalowe]

This is the error I am getting:

Compiler Error Message: BC30408: Method 'Public Sub DataList1_ItemDataBound(sender As Object, e As System.Web.UI.WebControls.DataListCommandEventArgs)' does not have the same signature as delegate 'Delegate Sub DataListItemEventHandler(sender As Object, e As System.Web.UI.WebControls.DataListItemEventArgs)'.


Why?

[dj4uk]

Ah yes use DataListItemEventArgs instead of DataListCommandEventArgs.

DJ

[brendalisalowe]

Cool. It works. But one more question. How does it know if you hit Ok or Cancel?

[dj4uk]

The confirm JavaScript function returns a true or false for OK and cancel respectively. If the Cancel is pressed the returned false stops the PostBack.

DJ

[brendalisalowe]

Thanks. That makes sense. Thanks for ALL your help!