AJAX :: Page State Lost During Postbacks With Updatepanel
Jan 14, 2010
1. I have couple of checkboxes and some text fields outside the updatepanel.
2. Based on the checkbox selection, I will be hiding/showing the fields to user using javscript.
3. I have a upload control in the same page which is placed under the updatepanel. When I upload the file, I will be reading the content of the file and I'm trying to load it into the controls which are outside the updatepanel. As I know the controls won't updated until unless it has been added under the updatepanel.
4. I moved all the controls outside the udpatepanel (checkboxes and textboxes) and placed it inside the updatepanel so that when the file is uploaded I can read the file and assign to the controls.
After this, I was able to assign the values to the control. However, the problem is, the state of the page (javascript hide and show) has not been retained during the postback. For example, if i have 2 checkboxes and 2 textboxes, if i click firstone, it should show the first checkbox. If I click the second checkbox, it will show the second textbox. By default, when the fresh load happens, first textbox will be shown. When I click the second checkbox (its showing the second textbox) and do the postback by uploading the file, the state gets lost and when the page load completes, it's showing the first textbox instead of showing the second textbox.
I have marquee control inside a Master page.I used timer control to refresh marquee for every 5 mins.And it is placed in update panel for implementing partial postback.
Now the problem is that,when ever timer_tick event raised it's postbacking the content pages as well.I need a solution to partial refresh of only master page.
I have a very simple UpdatePanel with tow buttons: "Add drop down list" and "Remove drop down list".
I was able to create and remove drop down list dynamically on the page.
My problem is that when I select an item in a drop down list and then click "Add drop down list", the page does not "remember" the selection of the first drop down list! How could I retrieve that selected item?
I am developing a web part that uses AJAX Timer and Update Panel to perform some data check. There are two buttons outside the Update Panel on the web part that I also want to maintain during the Timer postback. I cannot put these two buttons in any UpdatePanel because they need to call Response.Write() to display some Excel data to users in their On_Click event. My current solution is using ViewState to maintain these two button in On_Load event. However, I am not sure if this is a correct solution (haven't tested it). Does any one know that during a Timer postback, if I disable/enable these two buttons using ViewState in On_Load, will it update the page properly with the two buttons disabled/enabled? Or will it ignore any control that are not in the UpdatePanel regardless where you maintain it? If my solution is not a good practice, can someone suggest other alternatives?
I write code in asp.net I always solve issues by finding solutions with other members who have the problem before me. But this time I don't know how to do...
This is my problem :
I have a gridview inside an updatepanel and i modified some headers in order to filter the collection. This worked but when my updatepanel is updating, my textbox for the filter clear the value (the text) and lost focus.
This is my code :
[Code]....
[Code]....
The function FilterText(this) only set a timeout before fire postback.
I have an asp.net login page, which when initialized sets some session variables. When the user clicks login, an AJAX request is made which validates the user and sets additional session variables and returns a result to the client. The client is then redirected based on the login result. In the redirected page, I can access the session variables set when the login page was initialized (i.e. before the login) but none are present for those set during the login validation (part of an ajax call).
is this expected behaviour? Why would an ajax call generate a new session and thus cause the data to be lost?
I have a simple search page with a drop down list that I would like the value to persist on refresh..basically the user will select their location from the dropdownlist and this will be used to populate a gridview. After this the page is set to refresh at a set interval and use the same location data initially selected by the user. However the initial selection is lost each time the page refreshes.
p.s system is to old for ajax!
<meta http-equiv="Refresh" content="300" /> <script runat="server"> Dim connectionString As String = ConfigurationManager.ConnectionStrings("****").ConnectionString Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) If Not IsPostBack Then Dim conn As SqlConnection conn = New SqlConnection(connectionString) Dim Locationcommandtext As String Locationcommandtext = "SELECT * FROM [Location] ORDER BY [Location]" Dim loccomm As SqlCommand loccomm = New SqlCommand(Locationcommandtext, conn) Dim reader As SqlDataReader Try conn.Open() reader = loccomm.ExecuteReader() Locations.DataSource = reader Locations.DataValueField = "LocationID" Locations.DataTextField = "Location" Locations.DataBind() Catch ex As SqlException Response.Write("SQL Error: " & ex.ToString()) Finally conn.Close() End Try Else '"Viewstate should kick in here" End If End Sub </script>
I am having a custom ASPX page with following structure. Its having 2 update panel and I have a ImageButton outside them. The two UpdatPanel are triggered by this ImageButton.The Problem is whenever user clicks the Imagebutton, the image in the ImageButton is getting reloaded...it disappears and the reappears. I am not able to figure out why the postback is happening when the imagebutton is place outside UpdatePanel. Is it because I am using this Imagebutton for triggering AsyncPostBack in UpdatePanel?
I'm not sure if this is an error or is the right work mode for sql sessions.
I'm working now with Windows 2008 R2 Web Ed. and SQL Server 2008 Web Ed.
When I close my browse and open again a new browser window I need to login again in asp.net application and a new session is created in the sessions table in sql server.
It's this normal? I remember that with Windows 2003 and SQL 2005 this doesn't happend. When I closed my browser and open inmediately a new browser window my session was retained and I could continue working without relogin.
I am working on an asp.net website using C#. The site deals with orders and therefore order lines. I would like to store the order in memory whilst it is being populated (with order lines) and once it gets submitted write it to a database.
The above logic has been implemented, but sometimes when accessing session state or storing a variable in it information gets lost. Take note that the web server is running a dual-core processor. I am also using the in proc session state server.
I tried changing over to using the out proc session state server (asp.net state service), but it requires serialization. Since the order and orderlines are actually linq to sql classes, the entitysets and entityref's fail to serialize.
Does anyone know the reason why session state loses information occasionally and possibly how to eliminate the problem?
I have a problem with a couple of web sites where my session state gets lost prematurely.
I use the Inproc session provider and Asp.net 2.0. Which of these are true:
The antivirus software disturbs the session. IIS recycles the app pool every 2 hours and it does not retain the sessions during a recycle. Index server disturbs the session. Anything else that can have disturbed the session?
In the Page_Load() event handler for one of my pages I use the new statement about 100 times equating to memory allocation for about 100 objects. As follows:
using System.Web.UI.WebControls; Table mytable1 = new Table(); TableRow [] myrows = new TableRow[5]; TableCell [] mycells = new TableCell[100]; int i; for(i=0; i<5; i++) myrows[i] = new TableRow(); for(i=0; i<100; i++) mycells[i] = new TableCell();
My question is, should all of these new statements be enclosed like so:
if(IsPostBack==false) { // Initialize all controls for page just once during the session }
Or should the Controls be freshly allocated, initialized, and added to the page each time the Page_Load event handler is called? I personally don't think its efficient to create mytable from scratch every Page_Load since all I really ever change is the contents of the table and not the table itself.
I've got a rather difficult one here. I have a JavaScript jquery toggle button inside an update panel. Right now i'm using <form body="onload"> to recall this javascript to re-apply the button state after each partial postback. It works, but it requires two clicks sometimes.
The problem is... after a few clicks, it is significantly slowing down the PC, and I can see the clicks trailing half a second to nearly a second. If I have a group of buttons, all those click events are just catching up to my clicks. It is rather amusing but I suppose it has to do with the fact that the postback is calling the <body onload=" event> each time after the button is clicked.
I have a simple ASP page with databound grid (bound to an object source). The grid is within the page of a wizard and has a 'select' checkbox for each row.
And when the finish button is clicked, I iterate through the rows and check what's selected:
protected void Wizard1_FinishButtonClick(object sender, WizardNavigationEventArgs e) { // Set the selected values, depending on the checkboxes on the grid. foreach (GridViewRow gr in GridViewMatches.Rows) { Int32 personID = Convert.ToInt32(gr.Cells[0].Text); CheckBox selected = (CheckBox) gr.Cells[1].FindControl("CheckBoxSelectedToSend");
But at this stage GridViewMatches.Rows.Count = 0! I don't re-bind the grid, I shouldn't need to, right? I expect the view-state to maintain the state. (Also, if I do rebind the grid, my selection checkboxes will be cleared)
NB: This page also dynamically adds user controls in OnInit method. I have heard that it might mess with the view state, but as far as I can tell, I am doing it correctly and the viewstate for those added controls seems to work (values are persisted between postbacks)
UPDATE: Could this be to do with the fact I am setting the datasource programatically? I wondered if the asp engine was databinding the grid during the page lifecycle to a datasource that was not yet defined. (In a test page, the GridView is 'automatically' databound'. I don't want the grid to re-bound I just want the values from the viewstate from the previous post!
Also, I have this in the asp header: ViewStateEncryptionMode="Never" - this was to resolve an occasional 'Invalid Viewstate Validation MAC' message
I'm working on a webform with various controls. Depending on user-input I show/hide (using JQuery's show()/hide() functions) bits of the GUI. However if the form is posted-back and fails validation, I want the GUI to remain in the same state it was pre-postback rather than returning to the first-load state. Obviously the ASP.Net controls retain state, but I have HTML containers that are pure client-side objects.
In attempting to design a solution I find myself heading towards the murky (and tricky-to-debug) realms of hidden form fields - more reminiscent of my pre-JQuery work than anything 21st Century :-(
I am attempting to retrofit a web application that had a rudimentary, yet mostly effective navigation infrastructure that, when properly utilized, allowed navigating forward and backward through AJAX states and other pages through the use of additional <asp:Button> objects labeled "Back" to perform special code for restoring previous states. There was an elaborate stack push and pop algorithm for this. The effect was very similar to what is described in Diagram 1 (AStatex refers to an AJAX related state of the page). The reason for this is so that it takes away the reliance on the contrived Back button and so that accidentally hitting the browser's back button or hitting the Backspace key won't cause a loss of state.
I've a checkbox with autopostback=true. If i check the checkbox the postback occurs and changes a label text. But if i click back in the browser the checkbox is not returning to its previous unchecked state. How can i bring back its state?
Can i write some JavaScript to persist the state of a control?
1) I found that my viewstate was not being persisted across postbacks for web user controls. I ensured that the Enable Viewstate property was set to true (of the page)
2) The Viewstate isnt being persisted on the 1st postback.
3) However, it is being persisted from the 2nd postback onwards.
I stepped through the code to ensure that the Viewstate had the 2 keys that I was adding on page load. However, on the 1st postback, the viewstate is empty. Everything is ok from the 2nd postback onwards.
I have a requirement where i need to add file upload contorls dynamically.Intially i have a upload control in my page and button named 'Add fileupload' and another button named 'Upload'.the fileupload control is added dynamically when 'Add fileupload' button is clicked andUpload button is used to upload the files.when i click on 'Add fileupload' button after browsing the file to fileupload control, the new fileuplaod contorl has been adding successfully but the first fileupload control is empty.Can any one please help me how the state of fileuplaod control is maintained.Here is the code
