I'm currently having a problem with what seems like the Timer_Tick event interfering with the event handling for other controls within the UpdatePanel.
For now I have a Countdown label and some buttons inside an UpdatePanel. The Timer is outside the UpdatePanel and its Tick event is registered as a trigger for the panel. On every Tick, the Countdown's Text property is modified.
Whenever a button is clicked, a pop-up box will appear. However, I notice that if I click the button just when a Tick occurs, nothing happens. I'm assuming that it is because the Click event does not register while the UpdatePanel is in the process of rendering its updated contents.
Should I be using another type of timer instead? Is there a way to force the Click event to interrupt the Tick event? Or are there other ways to fix this issue?
Thank you.
You can nest your UpdatePanels so that your Label has it's own UpdatePanel.
Related
I have a page that consists of an updatepanel with a DropDownList, a textbox and a button in it. The updatepanel has a trigger for the button. This works fine for all my "error" cases, such as "No input!", when I pop an alert with
ScriptManager.RegisterStartupScript(UpdatePanel1, UpdatePanel1.GetType(),"noName", "window.onload = function(){alert('Please enter a username!');window.location ='Accounts.aspx';}", true); and the like.
But when I don't hit the alerts and the button event runs all it should I seem to land in some dead zone. My alerts stop displaying even though the code runs (checked by debugging), the button event does still preform all tasks as it should. However, if I refresh the page I get the classic:
To display webpage again. After I click retry my "latest" message pops up and then it works just like on first load.
So, I'm guessing that the PostBackTrigger on my button triggers a PostBack before or during the event execution since when the event is done nothing more happens until I reload. I'm thinking I need to add a reload at the end of my button event. Therefore my question is: How do I add a reload of the page/panel at the end of a button event?
Edit:
Forgot to mention that when the button event runs all it should it edits the web.config file, if this somehow could cause my issue.
I found a solution to my problem, by removing my triggers and instead using:
ScriptManager1.RegisterPostBackControl(Button);
Then I could also put an:
UpdatePanel1.Update();
At the end of my button event.
I am adding event handlers to a button like this:
btn.Click += new EventHandler(btn_Click);
However the btn_Click function is not being called (never hits the breakpoint in it) and the button just reloads the page. In my past experience, asp buttons usually perform the click code before reloading the page, so how do I get that to happen when the event is dynamically added?
I also set CausesValidation = false, although there's no validation on the page so I don't think that would have influence anyway.
The event handler needs to be bound for every request regardless of whether or not the page is being posted back. The binding of the event handler is lost at the start of each page request. Event handlers for buttons are typically bound in Page_Load.
You have to set event handlers on Load event (or before). If you do it after Load, it won't be executed since by the time the handler for the event is evaluated it won't be there.
Check this msdn article in relation to page life cycle. I think it will help you to understand. See that event handling occurs inmediatly after Load
I want to give the user the option to use a tutorial, the first time he uses the program. I tried adding it in the Form.Load event, but the forms shows up after the Messageboxes have popped up.
That's why I would like to know, are there any events fired right after loading a form?
If not, is there a way to perform actions right after loading?
You should try the shown event, which fires after the form is shown for the first time.
Load happens before the form is shown.
You could try using the Shown event but that might be a bit early too based on what you are doing but it does occur after the Load.
If you have any controls on the page you could trigger it off the controls GotFocus event. Just make sure to put in checks to only do it once if using the GotFocus method.
MSDN Form.Shown
MSDN Control.GotFocus
MSDN Reference to order of events
System.Windows.Forms.Control.HandleCreated
System.Windows.Forms.Control.BindingContextChanged
System.Windows.Forms.Form.Load
System.Windows.Forms.Control.VisibleChanged
System.Windows.Forms.Form.Activated
System.Windows.Forms.Form.Shown
The Shown event should do this for you.
What event I should handle to react to the completed change of the TextBox (i.e. when the user is
finished editing the content of the TextBox)?
There are several methods that you can use: Leave event, or a manual "typing stopped" event.
The Leave method is the most straight forward way of doing it, although as the event name suggests, it only happens when they TextBox looses focus, not when the user stops typing.
The TypingStopped event is something you would need to create yourself, but the basic idea of it is a short duration timer (say 500ms, but you would need to test it), which you restart on every KeyDown event of the TextBox. The timer would fire its own event and disable itself if it ever hits the end of it's timeout.
Edit: Updated to Leave event as per Hans' recommendation.
The Leave event is generally a good one for processing user input (for validation for example) as they move on to another part of the form. Just make sure that the event fires if they go from the textbox to any other UI element on your form - you may need to force a focus on the new element.
I have a button, contained in a panel, with a click event, that works fine. However when a users presses another button, I need to move this button into another panel (this is actually a panel with a modalpopupextender), so I this code to do so:
newPanel.Controls.Add(buttonPanel)
It all get's moved and looks fine. However now when the button is clicked it doesn't fire the associated event. I have tried re-adding the event in the page_init, with this code
((Button)this.FindControl("serverModalSave")).Command += new CommandEventHandler(modalSave_Click);
But with no luck. How can I get this button to fire it's click event when moved, and why does it stop working when it's moved?
EDIT:
This Button needs to be added to a panel specified by the user at run time, so there is not a way to determine where the button will go in advance.
I could instead of moving this button, create a new one, but because this button is not created in the page_init I am having issues getting that to fire an event either.
Instead of moving the button, have another button on the other panel set to hidden.
Hide the button you wanted to move and show the hidden one when needed.
Moving the control changes the naming hierarchy and now the button can't be found and the click event can't fire.
This is due to how the page life cycle works. Here is a good (if somewhat dated) article about how view state works - if you understand this, you will understand what went wrong.
If you are creating the button in the new panel, when this button is then clicked do you re-create it in the postback ?
You must re-create all controls on each postback see here