Web Forms :: Prevent TreeView Postback On OnSelectedNodeChanged?
Jun 11, 2010
I have a treeview loaded with nodes. When I click on a node that is set to .Selected, I want a frame to load with that node's objects. Instead, it appears that the TreeView is posting back and causing the node that was clicked to be lost. For example,setting the below function to OnSelectedNodeChanged causes a NullReferenceException.
Protected Function LoadObject(ByVal sender As Object, ByVal e As EventArgs)
Dim node As TreeNode = tv1.SelectedNode
Response.Write(node.Text.ToString())
When an asynchronous postback happened inside update panel, another postback happens also for MasterPagenot only update panel embedded page .I want to prevent this MasterPage postback . is this possible ?think like i have a MasterPage and another page which is test.aspx which is content page of MasterPagei have update panel at test.aspxwhen asynchronous postback happens at this test.aspx update panel it also loads MasterPage Page_Loadi want to prevent this (it should not also load MasterPage Page_Load)
I am checking to see on the form if they answer No to question one then go to comments. On the client side I added autopostback="true". So when the page reloads the random number in the label is updating to a new number. How can I avoid the random number not to be updated when the page post pack to itself?
Protected Sub form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles form1.Load Dtetxt.Text = Date.Now F() End Sub Private Sub F() Dim _r As New Random() Dim n As Integer = _r.[Next](5) ' Can return 0, 1, 2, 3, or 4 Label2.Text = n.ToString End Sub
I have a textbox of read only type with jquery datepicker so when the page post backs then that textbox value gets cleared. I do not want the textbox value to get clear but at the same time i need postback the page also..
I have an ASP .Net TreeView control that I am dynamically adding tree nodes to from my codebehind on Page_PreRender. The TreeView is populated nicely and the appropriate checkboxes are where they are expected to be. For each of these nodes the SelectAction=TreeNodeSelectAction.None. However, when accessing the TreeView CheckedNodes() collection in my codebehind after selecting a few nodes (checkboxes are selected) and clicking a submit button to post back to the server in the button click event, my CheckedNodes.count() = 0. I can not figure out why my CheckedNodes collection in the codebehind does not contain the nodes that I have checked from the GUI.
actually this code is working well in firfox mozila but it's not working in IE8
[code]....
here i want to prevent postback when answerlength == 0 ; but when answer length ==0 then it alert alert("u can't submit blank answer") message and postback to server io want to prevent it how i do ?
Simple one here... is there a clean way of preventing a user from double-clicking a button in a web form and thus causing duplicate events to fire?
If I had a comment form for example and the user types in "this is my comment" and clicks submit, the comment is shown below... however if they double-click, triple-click or just go nuts on the keyboard they can cause multiple versions to be posted.
Client-side I could quite easily disable the button onclick - but I prefer server-side solutions to things like this
Is there a postback timeout per viewstate that can be set for example?
Im using asp.net treeview in my apllication.i have apply css class for selecte node of treeview .MyNavTreeSelected { background-color:Gray; }
when i run the page first time last node of my treeview automatically set that background color as i applied in css.....and if i select any node of my treeview as soon as my css has worked but after page post back it just disapper...how do i maintain that css after postback... and last node of my treeview defaultly set css....
I have a web page (aspx) which takes longer time to load the page. If this page is loading and if user requests same page by clicking menu link again, it is considered as not postback and page starts loading again (as soon as it finished first page load).
I want to prevent this from happening. When page is loading and user requests same page again, it should not process those requests and should be neglected.
This aspx page is requested from menu (which is designed on seperate master page).
I have some validation JS code on client, that must be executed befor PostBack.If this validation code return 'false', postback is needless.How it can be disabled?
I'm using the ModalPopupExtender control from the AJAX toolkit. This control extends a panel which contains a CreateUserWizard control. However, the validation of the CreateUserWizard control causes a postback to the server, which closes the popup. I'd like the popup to remain open, even after the postback.
I am using a treeview control. I am buliding the tree dynamically. sometimes the tree becomes larger and the down scroll bar is need to see the entire tree. user can select a node from the tree. if one node is selected ,i change the color of the node from server side.
my problem is that if a user selected a node which is bottom in the tree(means, the user used the down scrollbar to see that node), after postback it shows the top of the tree.to see the selected node the user need to use the down scroll bar.
I need to show the selected node after postback. How can I do this?
I have a custom class (ServerSideValidator.vb) that validates user input on server side (it doesn't use any of the .NET built in validators, therefore Page.Validate() is not an option for me). I am calling the Validate() method on page.IsPostback event and the class performs without any problem
My issue is, when validation fails (returns false), I want to stop the postback event handler from firing, but load the page along with all the controls and user-input values in them. If I do, Response.End(), the page comes up blank. I can programmatically instruct the page to go to the previous page (original form before postback), but it loses all user-inputs.
I thought of creating a global boolean variable in the page code behind file and check the value before performing any postback method, but this approach takes away from my plan to provide all functionalities inside the class itself. The page object is being referenced to ServerSideValidator.
Seems like all the postback related properties/variables I come across inside Page class are 'Readonly' and I can't assign value(s) to control/prevent postback event from firing.
I'm trying to set the where clause on a LinqDataSource object bound to a GridView programmatically on a button click, but when the GridView rebinds data (for instance, when the user sorts) the Where clause resets back to the empty string. Is there a way to prevent this, or is there a better way to filter my results?
This code opens me a dialog box with Ok and Cancel button but it do not wait for user activity and post the page immediately and the label gets populated. I need to call the c# function based on user activity. If user clicks "Ok" label should get populated and if user clicks "Cancel" it should not call the c# function. How do I achieve this?
I am developing an application that manages a photo contest. In that application, I use an AsyncFileUpload control for the user selected photo. The server-side UploadedComplete does basic validation, and scales/clip the image as necessary.
The problem is, when i click on the submit button on the page, the content of the AsyncFileUpload gets sent with the other user-submitted data, so the user gets to wait twice as long to get a response from the server (I'm expecting photos that are between 3 and 7 Mb big, which takes a minute or two to upload).
My form looks like that:
<%-- ... snip - all other fields ... --> <div style="margin-top: 20px; margin-bottom: 5px;"> <span class="texteB"><b>Upload a photo</b></span><br /> Browse your computer to find a photo.</div> <div>
[Code]....
Is there something I missed out in the documentation? I've been working on this all day without much success.
