We are using Telerik 2017.1.228.45 RadTree controls. We have implemented RadTree contract inside a usercontrol and it's getting called through a master page. all Radtree nodes has a customUrl field populated,so when they are clicked on the same page, a user control appears and when some changes are made to that user control and is closed, RadTree loses its expanded state.
Is there a way to persist RadTree in that expanded state please? if yes, then how or if you could point me towards the right direction, that'll be great.
Thank you
This answer has solved my issue:
http://www.telerik.com/support/code-library/save-the-expanded-state-of-the-treenodes-when-the-treeview-is-being-bound-upon-each-postback
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I am trying a very simple thing. I have 3 textboxes and 3 labels. On text change i am setting the content of label.
The issue is when i insert some value in 1st textbox(e.g 50) change the focus to another textbox the values in label is reflected perfectly.
But the focus which i setted on 2nd textbox is lost. And the focus is lost somewhere.
I need to click again on 2nd textbox to get focus.
The same issue is reproduced if TAB is clicked to change focus.
I have made a small demo project for the same and attached. You can avail that from the below link
https://skydrive.live.com/redir?resid=A716D678775EEF95!115&authkey=!ABp6kAon_ZNDLBU
Please someone help me...what am i doing wrong??
Thanks in advance...
This is a rather common issue in ASP.NET, as described here: http://www.codeproject.com/Articles/17571/Maintain-focus-between-postbacks-in-ASP-NET-2-0-al or here: How do I maintain focus position in UpdatePanel after page partial post back. Those links also contain some suggestion on how to solve this issue.
One of the possible solutions is to keep track of control with focus, put information about it into a hidden field and manually restore the focus after postback. This method is described in the first link mentioned.
I am pretty new to ASP.NET programming. Now I try to add several web user controls to my page dependent on checked boxes in a tree view that I create from data of my database.
I was thinking about using iframes - one for the tree view and the other one for the controls, but this seems quite complicated. Is there an easier way to do this?
The tree view should always remain on the page an the web user controls should appear or disappear in a scrollable part of the page. Could you tell me what would be good practice to resolve this issue?
iframes would not be the easiest way to go about this (as you have two different server side pages that cannot communicate with each other).
If the number of controls that you are controlling visibilty for is not large, I would suggest that you have your user controls in a panel on the page, all invisible, and the treeview and this panel all on the page, within an update panel.
On check of the treeview, in the partial postback, show/hide the appropriate web user control.
As noted above, dynamically adding controls is problematic, as they have to be re-added every postback and you run into state issues.
Dynamic controls added to the page need to be added back to the page on every postback. I would not use iframes for this; instead, you can have the tree view on the left in a floating div, and another floating div for the right content. If the right content is always checkboxes, use a ListView, Repeater, or some other data bound control that builds the control tree for you. It's much easier to work with these controls as long as the UI is consistent. If not, you can build the right side dynamically. You'd have to readd the checkboxes to the page on all future postbacks.
I've got a master page with a section for subnavigation links on it:
<div id="sub_nav" runat="server"></div>
I programatically populate this with Hyperlinks when my main asp:Menu data is bound depending on the address of the page I'm on.
This works fine and all my correct submenu stuff shows up on each page. The problem is that when one of these pages does a postback, I lose all the links that were in my sub_nav div.
Now, I could just populate the div with links every time regardless of whether the master page load is a postback or not, but I figured there is a better way of doing this. I was thinking enabling the viewstate on the div and links inside it might persist them through postbacks, but apparently that is not how viewstate works.
What is the correct way of doing this?
Viewstate only stores the current state of a control and not the controls by themselves. If you are dynamically adding controls make sure to add them on page init method irrespective of postback
This MSDN sample should help you.
According to the excellent article TRULY Understanding ViewState, that's not really the purpose of ViewState. Furthermore, ViewState costs additional bandwidth so in general we want to avoid it if possible. It sounds like this data should be "cheap" to obtain (cacheable or whatnot), so I'd definitely populate it on every request and disable ViewState on those controls.
To understand the main purpose of ViewState consider a page with two buttons, btnA and btnB and two labels lblA and lblB.
When the user clicks btnA , the page posts back and sets lblA to "You clicked A!".
When the user clicks btnB, the page posts back and sets lblB to "You clicked B!".
With ViewState, the page remembers that lblA.Text was set to "You clicked A!" previously and restores that value. Without ViewState, if the user clicked A and then B, the page would only display "You clicked B!" because there's nothing to store the previous value of lblA.
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.
I have a simple user control containing two text boxes which I am adding to placeholder on Button Click event. I am storing the number(count) of clicks in View state and running a loop using count to create all previously added user control. I am also adding IDs to each User control (appending "UC" and count). I have also checked in view source the ids are same each time they are created. I have another button which basically does an post back. I have EnableViewState enabled ="true" in all controlls all the way up to Page Level.
My problem is that User Input does not persist on postback. please advice. Should this not be happening automatically for me?
Have a look at this:
http://www.denisbauer.com/ASPNETControls/DynamicControlsPlaceholder.aspx
I've encountered minor problems with it on a web farm, but for simple deployments its use is pretty straightforward. (Comes with source code, and the web farm glitch is a pretty simple fix.)
You need to create your dynamic controls in the Page_PreInit event rather than Page_Load or in a Click event handler. That way, they'll be there before ViewState, and then your posted values are applied.
I thinks what is happening is that you are creating your controls during the click event handler which happens AFTER ViewState and PostBack have been applied. This means your controls will be created empty each time.