DropDownList event not firing as expected

[Mark Rae]

Hi,

Apologies, but I appear to be having a senior moment...

I have a standard DropDownList webcontrol with a SelectedIndexChanged event,
as follows:

<asp:TableCell ColumnSpan=4 VerticalAlign=Middle>
Select your delivery location:
<aspropDownList ID="cmbShipping" Runat="server"
OnSelectedIndexChanged="cmbShipping_SelectedIndexChanged"
AutoPostBack="true">
<asp:ListItem Value="0">&nbsp;</asp:ListItem>
<asp:ListItem Value="1">United Kingdom</asp:ListItem>
<asp:ListItem Value="2">European Union</asp:ListItem>
<asp:ListItem Value="3">Rest of world</asp:ListItem>
</aspropDownList>
</asp:TableCell>


And the code-behind is as follows:

protected DropDownList cmbShipping;

private void Page_Load(object sender, System.EventArgs e)
{
if(!Page.IsPostBack)
{
BindData();
}
}

public void cmbShipping_SelectedIndexChanged(object sender, EventArgs e)
{
try
{
BindData();
}
catch (Exception ex)
{
CApplication.GlobalExceptionHandler(ex);
}
}

private void BindData()
{
// code to do the data binding goes here...
}


Problem is that the cmbShipping_SelectedIndexChanged() event only fires if
the SelectedValue of the DropDownList is greater than zero i.e. if I change
it from 0 to any other value, the event fires, but if I change it back to
zero the event doesn't fire...No errors are raised and, if I place a
breakpoint on the BindData(); line within the event code, it doesn't even
appear to jump into it...

I'm clearly missing something totally obvious...

Any assitance gratefully received.

Mark

 

[Mark Rae]

Problem is that the cmbShipping_SelectedIndexChanged() event only fires if
the SelectedValue of the DropDownList is greater than zero i.e. if I
change it from 0 to any other value, the event fires, but if I change it
back to zero the event doesn't fire...No errors are raised and, if I place
a breakpoint on the BindData(); line within the event code, it doesn't
even appear to jump into it...

Not only that - the event fires even if other controls on the page trigger
the PostBack...

Anyone got any thoughts on this...?

 

[Patirck Ige]

Do you have any sort of validations on your page?
Patrick

 

[Mark Rae]

Do you have any sort of validations on your page?

There is a form with a submit button which checks that the DropDownList in
question doesn't have a selectedIndex of 0 before submitting it, as follows:

<script>

function submitPayPal()
{
if(document.frmDefault.cmbShipping.selectedIndex == 0)
{
alert('Please select a delivery
location');document.frmDefault.cmbShipping.focus();
return false;
}
}

</script>

And the corresponding HTML is:

<input type="submit" value="Proceed to checkout" onclick="return
submitPayPal();">