The short version is that I have nested FormViews. I would like the child FormView to only change modes when the parent does so as well, so I handle the ParentFV.ModeChanging event and call ChildFV.ChangeMode within that...
For some reason, the Child FormView's mode doesn't change... nore does the Child's ModeChanging event appear to get fired...
Why would this not work?
EDIT: I came up with a workaround, hooking the Inserted and Updated events and using the KeepIn*Mode to prevent them from going back too early... setting the mode itself on page_load according to the current DynamicData mode...
Related
I add this in my Render method (custom webcontrol):
Me.Attributes.Add("onkeypress", "chang(event,this);")
If affects some textboxes if they have some properties. But there are times that i don't want this property to be set, so no javascript will be executed. I've tried to remove it in code-behind on page_load and i was going to try to remove it on prerender method but it happens before my controls Render method.
How can i remove this property?
Take a look at the ASP Events Lifecycle. As you can see, the render event is at the bottom of the execution list. Since no events are fired after render, and render is where you are adding this functionality, then render is also where you must remove this functionality.
You could try to move the function that adds it into a higher event (load for example) and then remove it on render. Either that, or when you are applying it, perform any checks to see if the objects requires it or not.
I am using entity framework 4.0 to bind a database object to a DetailsView on an ascx control. Within the DetailsView, I have a number of asp:panels that I'd like to show/hide depending on what's happening in that person's visit.
So, the first time through the page I'm setting panelA.Visible=false in the FormView_OnLoad event, and all is well - that panel is not output in the HTML. It listens to what I'm asking here.
Once I click submit and postback, I am again checking what's going on and setting panelA.Visibe=false in both FormView_OnLoad and EntityData_OnUpdating. But this time, when the page comes up panelA is showing.
I find that I can only hide that panel after postback by setting visible=false in DetailsView_PreRender, or by binding visibility to a public variable.
I'm thinking perhaps in the life cycle the DetailsView is binding again way toward the end, and throws away my visibility settings, even though they're not bound. So to show/hide panels within the DetailsView on postback, will I always have to set visibility on DetailsView_PreRender or after?
Am I on the right track here, or is something else resetting me at the last second?
Why can I set visibility the first time through the page but not postback?
You should always make final modification of your page structure after postback processing - that is the reason why PreRender event exists. Other possible event in your scenario can be handling DataBound event but better and more clear way is PreRender.
This is a little difficult to explain so please bear with me.
I have a procedure that is generating some radio buttons and assigning a CheckedChanged postback event based on the level being passed through (up to 4 levels). When the first level is checked (radio button selected) the postback event rb_CheckChanged00() is called and a check is done to see if this item has any children, if it does, it will create more radio buttons and assign rb_CheckChanged01 to the CheckChanged event for these - This part is working fine.
The issue I have is when I select the second Radio Button that has been created (the child), it doesn't seem to go to the post back event at all. The page is posting back when I click on it but everything resets because it won't go into rb_CheckChanged01.
I know this info is quite vague but I am hoping someone has an idea on how the post back event works and if I am somehow using it incorrectly.
Using: ASP.NET 2.0, IIS7
Thanks.
Most of the time when the dynamically created control's events are not fired, it's because the controls are 'reset' upon postback.
To make sure the same controls get created each and every time make sure that the control's IDs are set to the same values each and every time, before the ViewState is loaded. This way, when the control is added to the control collection of the page, once the ViewState is loaded, it'll persist it's properties. (just to describe what happens, in a nutshell)
One of the best articles I've read on this topic is this one. Make sure you read it, to fully understand what's happening in the background.
Looks like the child RBs are cleaned before they are able to trigger the event. From my personal experience, it's best to keep track of those dynamically generated objects, and regenerate them in every postback. The events will start to trigger :)
Your controls and events are not registered in the ViewState because dynamic controls need to be loaded in the Page_Init. Because they're not persisted in the ViewState, they won't be registered with events. A similar question:
Problem with dynamic controls in .NET
Only 1 thing can cause this, you create the rb's on page_load and don't add them to a List<> or something similar and that object to Session. What you need to do is when you create the items, Add them to a List and add that list to Session["RadioButtons"] and if the Page.IsPostBack is true, load your controls one by one from your list which is kept in your session to your page.
Is there not an event that occurs only when there has been some sort of visual change to an object. So for example if it were a video or animated object it would be firing as often as EnterFrame. However, if it were some sort of input control just sitting there doing nothing visually, then the event wouldn't fire until the visual state changed as a result of some sort of user input for example.
I've tried dozen's of events and none of them seem to fire this way.
For visual components about the closest you're going to get is FlexEvent.UPDATE_COMPLETE which will fire after an object has it's commitProperties(), measure() and updateDisplayList() called. If you're subclassing the component, then overriding updateDisplayList() and handling (or throwing you're own event) in there would ensure that you're only getting the event when something visual changes.
For video, you'll want to listen to VideoEvent.PLAYHEAD_UPDATE
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.