I have found many equivalent questions here, but non seem to apply to my problem.
I am dynamically loading controls into a Nested Masterpage. The button click event is not firing for buttons in different usercontrols, loaded in the Nested Masterpage.
When debugging, it seems like just a normal postback that occurs when a any button is clicked on the nested masterpage. No events are fired / caught in debug. The nested masterpage re-loads (post back), and that is about it.
Some Info that might pertain to the situation:
I am using codebehind for my methods, and where I expect to catch the event.
I have put the code that loads the uc's in the Nested MasterPage's init sub.
I have tested, and adding the control to the panel manually, everything is wired up as expected, throughout the lifecycle, and events are fired for the manually added control.
I have tested with using a static client ID for my buttons, as I thought the event might be wired up incorrectly. This did not have any effect.
I have manually assigned unique id's to my controls, no effect.
All usercontrol have and keep the correct properties set for them (Description, Quantity etc.).
I am reloading the usercontrols every time the nested masterpage loads.
I am not exiting on ifIsPostback, but instead reloading controls on every postback, as one of the buttons on the controls, might remove that control, and the new remaining controls need to be rebuilt on Page Init of the masterpage.
There is a script manager on the Master Page (not the nested masterpage).
I am making use of Ajax in the content pages, but not in the Nester Masterpage.
There is no update panel on the masterpage or nested masterpage.
All events are firing in a normal fashion on the content pages.
From my content pages, I remove and add controls to the nested masterpage dynamically. This works well and controls are loaded accordingly.
I am not setting the controls from the content page to the masterpage directly.
I am creating controls in my content pages, and pass them to a routine that manages a custom object containing all my controls, add and removing controls form this object as necessary.
In my Nested Masterpage Init event, I step through my custom controls
object and add them to a panel.
I am not sure how to debug the postback event in the browser, as I am
not making use of an udpate panel and Ajax for these controls in the
Nested Masterpage.
Here is the generated HTML for the Control that works (Manually dropped in at design time)
<input type="image" src="bookings_media/buttons/add-another-unit.jpg"
id="ContentPlaceHolder1_ucAddAnotherUnit1_butAddAnotherUnit"
name="ctl00$ctl00$ContentPlaceHolder1$ucAddAnotherUnit1$butAddAnotherUnit">
This is the rendered HTML for the dynamically added control:
<input type="image" src="bookings_media/buttons/add-another-unit.jpg"
id="ContentPlaceHolder1_ctl02_butAddAnotherUnit"
name="ctl00$ctl00$ContentPlaceHolder1$ctl02$butAddAnotherUnit">
Any ideas what might be snagging here:
Try using OnCommand instead of OnClick regarding the ImageButton.
Related
I am using a ajaxToolkit:AsyncFileUpload that allows the user to upload a excel file. In the AsyncFileUpload1_UploadComplete() event, I am reading the excel data and creating excel structure using div and adding to the page. But these dynamically created controls are not being added to the page. I added a button in the updatepanel and checked. On button click event, I created same above controls. In this case, the controls are rendering to the page. The controls are not rendering in case of ajaxToolkit:AsyncFileUpload only. Can anybody please tell me what is the fix for this.
Add Button into UpdatePanel where you want to show new controls and make it invisible with css style.
In the AsyncFileUpload1_UploadComplete server-side method, save your data to Session state.
In the client-side OnClientUploadComplete event handler call __doPostBack function with hidden button's UniqueID first parameter value. Then make all stuff required to render dynamic content in that button's click handler.
I have an UpdatePanel which contains all my page (I know, not an ideal solution), and I have some Panel's contained in this. Inside one is a control which I want to be a PostBackTrigger, but whenever I reference the button I get object reference errors, presumably because the control is nested. How can I expose this for the UpdatePanel?
I want to make use of "complex" usercontrols with more than one control element within. It's the same control I will reuse in the list, and I have a PlaceHolder control for it already.
I can add the control with LoadControl(path to .ascx) - no problem.
I can through my custom properties get/set access the embedded Labels, too, so I can initialize each control perfectly.
But when adding LinkButtons, I get into trouble/problems.
When I click the button, I do get a "submit" of the page rendering the controls; but the control's own button event does not seem to fire (or at least PageLoad on the parent page seems to fire first?) - I can't figure out where my event goes or where to look for a name/ID or parameter for this button.
How come or what am I doing wrong here?
I've made a "fake button" now by using a label more with a "hardcoded A HREF" with an ID in the URL, but I would like to learn what event I need to catch and where or how to init the button, because I want to be able to use "default ASP.NET" controls for these usercontrols (hopefully without too much patchwork-coding)...
The only reason that events get "lost" is because your controls are not being recreated in such a manner that ASP.Net can associate the event with the control after the postback. It does so through the use of the ID property.
In other words, you're doing one of three things wrong:
1) You're assigning the ID's of your linkbuttons differently during the creating phase in Init after the postback
2) You're creating your linkbuttons dynamically using code, but you're doing it after the Init phase of the page lifecycle, so that your controls do not participate in ViewState.
3) You're re-binding the datasource of the parent control containing the linkbuttons on every postback. Use if (!IsPostBack) to prevent rebinding it every time.
Without seeing your code I can't give anything more specific than that unfortunately.
I have button Add and Remove on my page.
Add button adds one checkbox, two textboxes and one dropdownlist to a new line on my page.
Remove button removes them.
I have this running nicely by following Joe Stagner's example.
Problem:
The controls that are created dynamically all need to fire the same event when checked (for checkboxes), also for selected index changes (for dropdownlists).
I have tried to add event handler when I create an object but it doesn't seem to fire?
you need to persist the dynamically created controls in some way [session, viewstate, etc.] for each page load. Recreate the dynamic controls and re-bind the events using delegates on each page load in preInit function.
I think you're probably running into the fact that your page, upon each page post, is being completely recreated - essentially the page has to duplicate what controls were on your page before it can attempt to feed postback (and events) to them. I think what you probably need to do is add code to your page_load which will re-create the dynamically created controls, with the same ids as they had, and register the event handler.
Sounds like you have a page life cycle issue.
For a dynamically created controls to fire events you should create them in the PreInit event of the page.
Here's a link to a cheat sheet for Asp.net page life cycle.
yeah,
like what all said, it is Life cycle issue.
when you load user controls dynamically you should always do the following.
Assign a unique ID for each User Control.
Reload the user controls on Page_Load or Page_Init Events.
and to make it all easier i suggest to abstract the loading to a function that you will call from Page_Load and Page_Init as mentioned before, this function will check if hte target user control was loaded and will load it again for you, to do that, you store the loaded user controls IDs in Session or viewstate.
hope this helps.
If you want to do it without auto post back you can remove the auto post back and throw and ASP button on there. Any runat server should fire off your dynamic event handlers.
I ran into a problem recently when using a repeater that I was adding dynamic controls into and although I've got a workaround that does functionally exactly what I want it to do, I'd like to know if there is a better way to do it for my understanding. I've been working with ASP.NET for about 6 months now, and everytime I think I've got the page lifecycle/viewstate completely sussed something crops up that I can't answer.
I was creating a form where users could register their interest for an event, and register for multiple people.
The aspx went something like:
<asp:Repeater ...>
<bunch of formatting and always there controls like firstname/lastname/address>
<asp:PlaceHolder ...>
<dynamic controls for workshop selection go here>
</asp:PlaceHolder>
</asp:Repeater>
An event can have workshops that the user can register for, and the availability of the workshops is dependant on the date that they choose to go to the event on. The availability of the workshops is dependent on the date, so they can't choose the workshops until they've selected a date.
Anyway the dynamic controls that I'm adding are basically a bunch of literals and a bunch of radio button groups.
I started off by adding the controls in the ItemDataBound event handler, but when saving my repeater items back to my delegate list the ViewState of the radio buttons was never updated. All the fields that were referenced in the ItemTemplate were handled fine, but not the radio buttons I was adding dynamically.
I tried to use the ItemCreated event instead, adding my buttons there, but that didn't seem to make any difference. In the end I settled on a workaround which was based off of this. Basically I'm just outputing the HTML input fields in a literal and reading them back from the request.
It all works perfectly now, and I'm happy with the functionality, it just seems really dirty to have to output the radio buttons as HTML inputs directly rather than use a server side control. Does anyone have a clue about why the ViewState wasn't being restored properly?
Just to be clear, the controls were recreated in the same order everytime, with the ID properly set. I'm using dynamic controls all over the place and they're working fine, I just can't get them to work in this case when I'm adding them inside a repeater.
//more clarification
I can't create these controls in Page.Init as the user selects the date which causes a postback and I have to wait for the viewstate of that control to load before I create the dynamic controls.
You're creating (or re-creating) the controls when the repeater is bound to its data source. If this happens after the ViewState has been loaded by the page, the ViewState won't be available to the dynamically-created controls.
Check you're binding your repeater early enough - Page.Init is OK; Page.Load is too late.
It is worth noting that Radiobuttons controls do not work 'out of the box' in repeater controls. Repeater controls inherit the INamingContainer interface which ensures all rendered html controls have unique name attributes. As radio buttons use the name attribute to group themselves this means you will not be able to create groups of radio buttons i.e. setting the GroupName property will not have the desired effect as the Repeater will override this and create unique names for each RadioButton.