So what I have is a bunch of dynamically created textboxs that when the user enters some data and either tabs out or clicks out some calculations are done. After the page posts back control focus is lost. What I need is to be able to set focus back to the control that was tabbed to or clicked into not the control that data was entered into.
You'll have to send information about that control in the post. What happens in a postback is the the browser completely discards the current DOM and loads a brand new one, so to keep your place you'll have to tell your server where your place was and have javascript code that runs on page load to put things back.
Other options include doing this either entirely in javascript or using an ajax partial postback.
Related
Currently I created a wizard with a listbox. The listbox has a next and previous button. The listbox has thousands of items but the next and previous will show them 30 items at a time.
I am not using AJAX so the page reloads each time the button is being clicked. I don't want the page to reload everytime the user clicks next and previous. I thought of using AJAX.
Is there anyway I can prevent the page from reloading either by AJAX or a different way everytime the user presses next. Pressing next triggers a stored procedure which selects the next 30 items.
C#, SQL, ASP.NET, HTML, JavaScript
You can surely use jquery for this purpose. It will allow you to do an ajax request. In fact, ajax request can be done from a .Net page with even plain javascript and it has nothing to do with .Net version.
However, using jquery will make it easy and you will be able to easily populate the listbox using the results from server.
I have a menu on a .aspx page, which will load a specific user control depending on which menu option is clicked. This part is working fine.
The problem I'm running into is when I instantiate a post back from the dynamically loaded user control, the .aspx page is reloaded. Now after researching a few of the other questions on here, I gathered that I have to recreate the User Control each time the post back is instantiated. However, the question I have might be quite simple, but how do I reload the specific User Control (and fire an event such as OnClick) based on what is posted back to the server?
So my question is: What exactly gets passed back to the server on post back, and is there something in the post back request that will allow me to load the specific control? If there is, how would I get to it?
To do it the manual way, you would have to recreate the control(s) before ViewState is reloaded, like during OnInit for example.
There is a control called the DynamicControlsPlaceHolder that takes care of persisting dynamic controls for you. It's a definite time saver, and it makes persisting dynamic content easy.
Here is a link to the control:
http://www.denisbauer.com/ASPNETControls/DynamicControlsPlaceholder.aspx
To better understand what postbacks do, you need to understand the ASP.NET page lifecycle. Here is an MSDN article that explains it in detail:
http://msdn.microsoft.com/en-us/library/ms178472.aspx
In my page I have a 'Button' when I click it, it loads an instance of my 'UserControl' to a 'PlaceHolder' .. I've used the 'UpdatePanel' but it was a hazard! .. I think it's because the Asp.Net 'Ajax' sends the whole page to the server and behind the scenes it actually causes a full PostBack. and it will help me if I could implement a partial PostBack so I won't need to save or access my database each time I reload or click the button to re-assign the values to my UserControl.
So I was hopping for some samples implementing a partial PostBack to load only one instance of my UserControl.
I can't post the code in my page here because it's a REAL MESS! .. but if you really need this to help me then maybe I could send this and post a clean solution here on the question.
Thanks for your time .. I hope there's some simple answers to my question because I'm really hopeless here!
The UpdatePanel always causes a postback to the server for the entire page, and only updates the UI's within the update panel. That's just how it will always work. If you only want to load a user control, consider using a JQuery approach to pull the user control from the server and render it via client-side JavaScript.
http://www.codeproject.com/Articles/117475/Load-ASP-Net-User-Control-Dynamically-Using-jQuery
http://samuelmueller.com/2008/12/dynamicloader-plugin-dynamically-loading-asp-net-user-controls-with-jquery/
HTH.
I have a asp.net page with c# code behind. I have a first panel where the user selects and enters information, they then click continue and that data is stored in variable. A new panel displays on screen and the select some new data which when they click continue stores that data in that panel and sends all the information to a c# program. The problem I an getting is that when I click continue the first time and the page refreshing showing only the new panel all the data defaults to 0. How can I fix this?
Thanks
HTML is a connectionless protocol. This means there is no state. There are ways to mimic state with .net, but html has no means of this by default. If you are using webforms, you can utilize viewstate as long as you are posting back to the same page each time. If you are using mvc, you will either have to submit your data via ajax or you will have to send all the initial data you sent to the server back to the view so when you press continue you can populate it all again. Or just use jQuery/javascript to hide(), show() portions of your page, but wait till everything is completed prior to posting to the server.
Good luck
I have a page which the user gets shown when he wants to create a new or edit an existing document. There are two UserControls on the page. One simple DatePicker and a more complex grid. After filling out or editing the data he then can press continue which brings him to the review page where he can decide to really create or update the document or go back and change something. Going back is done in javascript with a history.back()
Now when the user is in "new" mode and decides to go back from the review page the grid partially looses its viewstate and the DatePicker loses it completly.
On the other hand when the user is in "edit" mode and goes back from the review page both controls maintain their viewstate.
I know that the browser just shows the cached version of the "new/edit" page. But why the difference in the state of the controls and what can I do so that it works in both cases?
Viewstate is essentially a hidden field in the form that gets populated with the control values that have been posted back to the server.
If a user enters or selects some values in the form's controls, performs a postback and then presses the browser's back button or does a javascript history.back(), you are viewing the page as it was before the postback took place. Therefore, the choices made by the user prior to the postback will not be present on the page.
The difference between "new" and "edit" is that on "edit" you are retrieving information from the database to populate the controls.
Instead of doing javascript history.back(), you should look into using a Wizard control. The wizard control is designed for this very purpose. If the user enters information in multiple steps, goes to the review page and needs to go back a step or all the way back to the first step everything is maintained in Viewstate.