I have put several controls into an UpdatePanel. When I press the button inside the update panel there's no progress bar on the bottom status bar and there's no typical click sound that occurs during a normal postback. But the page still flickers to the top and I cannot see the validation errors. Could it be because I have a DataGrid on the update panel. I heard DataGrid and Updatepanel don't work well together.
Are you using any validation controls? I tend to add Validation controls but forget to assign the ErrorMessage text which often cuases me ponder why something isn't working.
Related
I would like to embed a ListBox into an UpdatePanel. The ListBox needs to have multi select enabled, with a post back triggered on item selection. My problem is the scroll bar on postback. It gets back to the top everytime an item is clicked. I have tried different ways to back up the scroll position, there is just always something wrong with it (at least in IE8, the browser I have to focus on). Either I get a flicker, or as soon as the user uses his mouse wheel after post back, the scroll bar will then jump back to the top. This does not happen in Chrome and Mozilla.
I was thinking, maybe there is something that should work - posting back without ever redrawing my ListBox / udpating the containing UpdatePanel ? Is this possible ?
Any full postback will necessarily repaint a list view so maintaining the scroll position of the listview is going to be problematic
Smart Nav
If it is the position of the page scroll position you are struggling with then you could try smart navigation
http://msdn.microsoft.com/en-us/library/system.web.ui.page.maintainscrollpositiononpostback.aspx
I don't think browser coverage is going to be hugely reliable for this (for example see http://forums.asp.net/p/1094179/1651390.aspx)
Update Panels and postback controls
If you are just updating the content in the update panel then it shouldn't lose it's page position. Make sure you are doing the partial post back and not the full. The listbox and the control triggering the postback should both be within the update panel.
There are caveats to this though - if you have a button outside of the update panel it can trigger the partial postback if it is in the triggers collection of the panel (http://msdn.microsoft.com/en-us/library/system.web.ui.updatepanel.triggers.aspx)
JQuery AJAX
The nuclear option would be to use JQuery AJAX or similar e.g. proper AJAX not the strange fake halfway house stuff that the update panels use (not to say that they aren't very useful - just need to be used judiciously). JQuery AJAX is a swine to get working within the postback architecture so I wouldn't necessarily recommend.
Maintaining the ListBox scroll position
Note - if it is the listbox scroll position that you are concerned about them this question
Maintain scroll position in listboxes in updatepanels, NOT the page
gives some good advice
Hope that helps some
I think flickers could always happen whatever you do (flickering is actually the browser that renders contents in several phases).
You should start by trying the MaintainScrollPositionOnPostBack page's property.
http://msdn.microsoft.com/en-us/library/system.web.ui.page.maintainscrollpositiononpostback.aspx
Why do you need to postback on every item selection ? Don't you mean an async postback ?
I had a similar issue with a ListBox inside a user control, and who in turn was in an UpdatePanel. I used jQuery to deal with click events on two buttons that were selecting and unselecting all items in the listbox.
Try this:
Create a .js file (e.g. select.js) and insert your jQuery code in there. Something like:
function pageLoad() {
//insert code here
}
Important to use pageLoad() instead of (document).ready.
Then, insert the script reference in your ScriptManager:
<asp:ScriptManager ID="sm" runat="server" EnablePartialRendering="True">
<Scripts>
<asp:ScriptReference Path="~/Scripts/Select.js" />
</Scripts>
</asp:ScriptManager>
I have asp.net application and a TabContainer from AjaxControlToolkit on a form. There are 4 tabs, each containing UpdatePanel, hidden button and some custom .ascx (each with it's own javascript file). Buttons are triggers for panels to update the contents and they are triggered from the 'OnClientActiveTabChanged' event of the TabContainer.
This technique is described here and similiar here. It's pretty simple when looking at it.
The only problem I have is that the whole scenario works when used as a separate page but it doesn't seem to work when masterpage is around that page. Suddenly buttons act as full postback controls.
Do you have any idea what's the reason?
Assuming the buttons your referring to are on the master page, I think you'll want to register the master page buttons as update panel triggers.
http://www.asp.net/ajax/tutorials/understanding-asp-net-ajax-updatepanel-triggers
I have one aspx page that has two UserControls on it; each is primarily a ModalPopupExtender. One has validators; one does not. The one that does not has a Submit button with the CausesValidation="false" attribute on it.
When that Submit button is clicked, nothing happens. Click it again, and the postback happens as expected. There is clearly some validation issue going on here, because if I remove all validators from the page, the postback succeeds on the first click.
What's going on here?
Without seeing the code, I can't say this for certain, but it sounds like you may need to utilize the validation groups. The validation group would be set on the validation components as well as the button that posts back the page.
Make sure that the buttons that show the ModalPopups are marked CausesValidation=false as well. What was happening was that the "Show Dialog" button for the non-validating dialog was not marked this way; this was causing the entire page to validate when that dialog was shown - including the other dialog, which did have validation and was failing it. This caused the Submit button to fail for apparently no reason.
Moral of the story: Make sure to use CausesValidation on any buttons that don't require it, and use Validation Groups to separate out various page parts, especially when parts of the page are not visible.
Have you tried removing the OK button property from the modal popup?
I have a panel on an aspx page which contains an UpdatePanel.
This panel is wrapped with both a PopUpControl Extender as well as a DragPanel Extender.
Upon initial show everything works fine, the panel pops up and closes as expected and can be dragged around as well.
There is a linkbutton within the UpdatePanel which triggers a partial postback. I originally wanted to use an imagebutton but had a lot of trouble with that so ended up using the linkbutton which works.
Once the partial postback is complete I can no longer drag the panel around.
I would love to hear suggestions on how to fix this.
Has anyone else encountered this problem?
What did you do about it?
Do you know of any other way to accomplish this combination of features without employing other third party libraries?
Take a look at when the drag panel extender and popup control extender actually extend your panel.
Chances are those extenders work on an initialization event of the page. When the update panel fires and updates your page the original DOM element that was extended was replaced by the result of the update panel. Which means that you now have a control that is no longer extended.
I don't really know of an easy solution to this problem. What will probably work is if you can hook into an event after the update panel has updated the page and extend the panel again.
I've got a web application working using VB and Ajax. I'm using updatepanels to avoid the irritating "flicker" on postbacks to the server.
I would like to have a button control defined within the updatepanel itself (tried moving it outside and got some catastrophic error, so left it there) that makes the current panel not visible and a sibling panel visible. This works with the exception that the button must be clicked twice. Not double clicked, but clicked once than clicked again.
In setting breakpoints I discovered the code behind that's attached to the button is actually being executed on the first click, but the panels don't switch as expected. If I click the same button OR worse yet, a different button, the expected behavior of the second panel appearing occurs. However, with the second button being clicked there's an unwanted bonus of a third panel being displayed, the third panel being made visible due to the second button being clicked.
I'm assuming this behavior is due to the updatepanel and its Ajax nature. Is there a way to avoid the second click? Am I misusing the updatepanel? I really wanted to use a modal popup (right out of the AjaxToolKit) but had problems with posting back the data so I opted for this approach. Any insights, assistance, even criticism would be welcome as this has plagued me long enough. Thanks
If you get rid of the UpdatePanels do things work as expected with PostBacks? Chances are something in your Page_Load or other event higher up the chain are "resetting" things in some way before it gets to your click event. Could this be the case?
I think your problem is that only the update panel is receiving data from the server after the method executes. The panel your are trying to change is outside of the update panel so it does not know that its properties have changed.
You either need to do a full page postback or have the panel you wish to modify inside the update panel.
I have run into this before and resolved it, I just can't remember how. I will try to find my old code and get back to you. one thought, do you have EnablePartialRendering enabled in your scriptmanager? maybe try wrapping both containers in a third panel.
Your update panel is sitting inside the other panels.
Should that be the other way around? AFAIK only controls within the update panel will get updated in via the AJAX call.
Here's a fairly simple solution. (I was having the same problem this morning.)
The UpdatePanel can't render stuff outside itself. So, as you noticed, the updates are happening, but you're not seeing the result.
The easiest solution is to force a full postback. You can do that like this:
protected override void OnInit(EventArgs e)
{
var scriptManager = ScriptManager.GetCurrent(this);
// or this.Page in a UserControl, etc.
scriptManager.RegisterPostBackControl(someButton);
scriptManager.RegisterPostBackControl(someOtherButton);
// etc. for each control that needs to update something outside the UpdatePanel
}
This still allows the buttons themselves to be updated in the UpdatePanel by Ajax (e.g. changing their state to disabled or enabled). The full postback only happens if the buttons are clicked.
Like others have said an update panel only updates its contents, thats one of the main benefits of using it.
Panel2 and pnlPrvCmt need to be inside your update panel for your button click method to work. Another option would be to put Panel2 inside one update panel and pnlPrvCmt inside a second update panel. Then any control inside either update panel will cause both to refresh, as long as the UpdateMode=Always (which it is by default).
Try giving the dynamic control an ID when it is created. For some reason this is required by .net for a dynamic control to work in this context.
myControl.id="newID"
I have found this to occur under 2 different scenerios:
No ID set on the control. Either the ID is left off of the markup or the the ID was not set when a dynamic control was created. ASP.Net uses the ID to track actions.
Nested UpdatePanels. Scenerio: When using a Masterpage, you might have a content placeholder that you wrap in an UpdatePanel so that an UpdatePanel is not needed in the content on the page. Then, in developing your page you might, as a habit, add an UpdatePanel.