User control retains focus incorrectly after TextChanged postback when UC is contained within a detailsview control

问题

I reference a previous post: Focus lost on partial postback with UserControls inside UpdatePanel where an excellent solution works perfectly for web-page controls within a form. However, I have placed my UC inside a detailsview template-field (for Edit+Insert).

The UC contains an UpdatePanel needed to adjust the text-formatting and control's style(s) following the TextChanged event of the UC-textbox (AutoPostback=True) during the Edit-mode and Insert-modes of the DetailsView.

As such, when the DetailsView-control is in Edit-mode, and user changes Text in the UC, the textchanged event is fired and the user-entered value is validated and when OK, the thousounds-separator (comma) are added to the UC-textbox-text, BUT, the focus moves to the next field in the DetailsView and QUICKLY returns back to the UC-control.

This incorrect focus-move(s) does NOT occur when the UC is wrapped in updatepanels as noted in the referenced post since the focus and tabbing order works perfectly outside of the DetailsView control.

Here is the aspx markup for the template-field-EDIT (only).

<asp:TemplateField HeaderText="Initial Mileage" SortExpression="IMilage">
<EditItemTemplate>
<asp:UpdatePanel ID="updpnlIMilage" runat="server" UpdateMode="Conditional" >
    <ContentTemplate>
        <TGANumeric:GANumeric ID="ucnumIMileage" runat="server"
            Caption="Initial Mileage" HideCaption="True" Width="160"
            DisplayMask="999,999" InputMask="999999"
            Enabled="True" IsRequired="False"
            MinNumber="0" MaxNumber="999999"
            Text='<%# Bind("IMilage") %>'
            TabIndex="0"
            />
    </ContentTemplate>
    <Triggers>
        <asp:AsyncPostBackTrigger ControlID="ucnumIMileage" />
    </Triggers>
</asp:UpdatePanel>
</EditItemTemplate>

Thanks in advance. Your comments are welcome. Thanks...J.

回答1:

So are you saying your control hierearchy (partial) is:

UpdatePanel > TGANumeric:GANumeric > UpdatePanel > TextBox

This is an awful lot of overhead to just format a number with a comma, which is the only reason I see for your posting back. As far as I can tell there is nothing you need from the server, so why post?

Or is there?

My thoughts, lose the update panels, disable the AutoPostback on the Textbox, handle the formatting client side if it must be seen immediately, or leave the formatting to the DetailsView field DataStringFormat when it posts after save.

I'm betting this will clear up any focus issues.

回答2:

Based on all the comments in this thread, I want to explain the actual root cause of the tabbing misbehavior.
1) There were no coding issues or event-issues with the user-control.

2) There were no coding issues or event-issues with the layering of Master-page, Content-page, Ajax update-panels / nested update-panels, details-view and template-fields containing the user-control.

3) The real culprit was a small snippet of code where the page adjusts the web-controls on the form based on the "state" (status) of the page/form. I manage the adjusting of visible and/or enabling of web-controls in a single subroutine in the code-behind so that all of this enabling/disabling visible/not-visible occurs in one place under a set of CASE-statements. The actual erroneous snippet of code inside the 'sbSetFormState()'-method was messing with the class-variable 'm_eFormState' that actually caused the update panel to re-fire and thus the tabbing got thrown out of sequence.

This was discovered by the great suggestion from 'fnostro' to remove or add functionality features until the mis-behavior exposes itself. I mark this topic as resolved/closed. Again, thanks to fnostro !!!

来源：https://stackoverflow.com/questions/27650321/user-control-retains-focus-incorrectly-after-textchanged-postback-when-uc-is-con

标签

ASP.NET

user-controls

ajaxcontroltoolkit

detailsview