I am in beginner level on developing web pages. I was coding on desktop applications and as you know it is easy to say that web applications are extremely different than desktop applications.
I wonder why data are lost between postbacks.???? And what is the best way not to lose the data belonging to a specific control (especially gridview). Session or viewstate or anything else?
Never had this happen before. I just upgraded my site from 3.5 to 4.0. Here's the scenario:
1.) I have a literal on a web form, in an UpdatePanel.
2.) On PostBack, the Literal's "Text" property loses it's value. The ViewState is enabled throughout the page. Further, I changed the Literal to a label and it also has this problem. The TextBox's appear to keep their values.
3.) If I remove all of the Ajax controls (which currently is just the UpdatePanel and the ScriptManager) then the Literal control keeps it's value through PostBacks.
4.) There is no client side JavaScript where I'm manually changing the values of these controls. They are only editted in the server side events.
I have read that setting the AutomaticDataBind property in the web.config could remedy this but I can't find any documentation on it and I don't know where to put it in the web.config to even try it.
This is weird. In my newly developed chat application, when I invoke Response.Redirect, I am losing my session data. What is particualrly odd is that this sometimes seems to occur after a slight delay, so I reach the page, and then the session info gets lost momentarily thereafter. Mostly though it seems to get lost immediately. I have of course googled this issue, but yet to find anything that speaks to my problem. SessionState is in InProc mode. Session state has been working fine for me until this unexpected problem, so everything is configured right. So far the only workaround I can think of is to use a link instead of a button, and use javascript to call a server-side function on onclick to do the work I need to do before the link gets invoked. Messy, and I'd rather not go that way unless there's no alternative.
Just to preempt one red herring, I do use Response.Redirect(<address>, false).
The problem occurs both on the testing and production servers. I'm running ASP.NET 3.5 on IIS7.
I am trying to set a session variable in the global.asax file and keep running into the problem that the Session is null.
I am running my application in VS2008 and using asp.net 3.51.
Here is my code:
1. In my web.config file I have enabled the session state and added the following line;
<sessionState
cookieless="false"
mode="InProc"
timeout="60"
></sessionState>
2. In the Session_Start procedure in the Global.asax file I set the session variable to a default value.
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My problem seems to be that when the Application_Error procedure is executed the session state is lost.
Does anyone know why the session state isn't available in the Global.asax file.
I have two radio button list:
*1* report views -- 4 options -- NOT in updatepanel
*2* pagination views -- 2 options -- IS in updatepanel
The situation goes as follows: Refresh WORKS in default setting but when I select *2* radio button options and refresh the page renders the state that the (1) was entered in.
Example: () are the radio buttons
Report Viewing: () (x) () () Pagination View: (x) () REFRESH works!
Report Viewing: () (x) () () Pagination View: () (x) REFRESH fails to display Report Viewing: () (x) () () Pagination View: (x) ()
Report Viewing: () (x) () () Pagination View: (x) () REFRESH works!
OR: () are the radio buttons
Report Viewing: () () (x) () Pagination View: () (x) REFRESH works
Report Viewing: () () (x) () Pagination View: (x) () REFRESH fails to display Report Viewing: () (x) () () Pagination View: () (x)
Report Viewing: () () (x) () Pagination View: () (x) REFRESH works
I am using the session variable to hold the Pagination Viewing option but during page states, I've noticed that when a 2nd option is selected of *2* radio buttons (doesn't matter of 1st or 2nd option was initially selected) that during debugging mode the step over corrects the issue but not the right table viewing. Upon entering Page_Init selection selection index of radio button list returns to 1st option.
I'm fairly new to ASP.net development as may have been noticed by some of my other posts and so here goes another one.I have a web page in which I allow users to enter data that will be used to populate a database and then graph data based on the information that was saved in the database. I have 10 sets of criteria that the user can enter and as they enter values for each individual set, I make sure all the parameters are filled in and set a variable called blnParm1, blnParm2, blnParm3, etc. Anyway, as each DropDownList box fires off an event the values of my blnParm variables is reset because each time the event is fired the page is PostBack therefore my variables are redeclared. I know the page is being PostBack because each of the DropDownList boxes have AutoPostBack set to true. I had to do this so that I could get the OnSelectedIndexChanged event to fire for each of the DropDownList boxes. So, how do I preserve my variables through this PostBack or how do I get the events to trigger without calling AutoPostBack?
Some more info, my variables are declared globally in my aspx.cs file as private bool. The code is working like it should as far as populating drop downs dynamically based on other data input by the user, the controls all have their values preserved as the page is PostBack.
I have a asp.net application where I am saving off into session the user privilege information. From a grid I am bring up a new window by using the window.open. It seems that it is whiping out the values in session. A temporary bandaid I have placed on it is to recall the database if the value is nothing to reset the user object. I have found all over the internet that this is an issue with the window.open in IE 7 and IE 8. Has anyone else run into this and able to actually fix it?
View 4 RepliesThere are a couple of user's experiences session variable loss after they've clicked a confirm button and their information is email via a relay hosting server. Below, I commented exactly where the session variables get lost.
What could be causing the session variable loss? So far, this only happens to a few users.
Part of the email that gets sent out:
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Web config file:
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I have a Gridview some columns is TextBox , the layout looks like this
{saveBUTTON}
Delete | No | NAME
Button , Binding Column , TextBox
Button , Binding Column , TextBox
User can modify Name column then click saveBUTTON to update data
I have a problem is
if user do this steps
1 modify the TextBox in GridView
2 delete row from Textbox without click the saveBUTTON before
then... all the textbox in GridView was be rebinding... all the data user input was missing..
how to keep data in Gridview ... so after user delete data I can rebinding to GridView?
I have a webform will perform a server.transfer to another webform. Upon postback on the second webform, i am not able to retrieve the previouspage data. is there anyway i can achieve this?
View 4 Repliesasp.net session data lost on postback of the page in windows XP.
View 4 RepliesI have the following tabs. After a postback, the tabs automatically gets focus back to 0. I want it to keep on the same tab before the postback. What's a great way of getting this done.
<div id="settingspagetab">
<ul>
<li><a href="javascript:void(0)" onclick="changeTab(0)">General</a></li>
<li><a href="javascript:void(0)" onclick="changeTab(1)">Site Layout</a></li>
<li><a href="javascript:void(0)" onclick="changeTab(2)">Marketing</a></li>
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I have several dynamic user controls that I want to keep them in each postback. but the problem is when I click on menu item at first time, every thing disapeare in my page! even the things I created on design time. would somebody please help me to find out the problem of my code?it's realy urgent!!
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I am creating a simple string of values that get added to a label after a post back. I am setting the values thorugh ViewState. However, my appended values do not get updated until AFTER the 2nd postback. Example:
On Page_Load the label displays a "0";
If I enter a "1" in the text box and click the button the label still displays a "0";
If I click the button again (the 2nd postback) then my label correctly displays "0,1"; This works for whatever value I enter after. i.e. "0,1,35,hello world", etc.
What I am I missing? Code Below.
.ascx - I left out inherits and codebehind
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I have an upload control (csv file) of which I use the stream to retrieve data in a datatable that I then bind to a datagrid, sitting in a repeater control.I have to bind more than one record to the repeater, therefore I need to find a way of storing the stream for each binding, so that I can bind it to the datagrid again, via itemdatabound event of repeater.
I have tried storing the stream in the repeater's datatable but on each postback, the content of the stream gets lost. The stream still exists, but its length is set to 0.I have tried storing it in a session object, but again it is reset to 0.
I have tried using viewstate but I get a xmlserialization error. Saying IXmlSerialization is not implemented.I am desperate to find a work around as I am feeling the pressure at work.
I have a slight delemma that I have not been able to work out.
My Scenario is:
Page_Loads > Calls Sub Random Data Retrieved from a Table - Displayed on screen & Sets Variables from Row(0) for an Insert Statement > Click Button to Insert those Variables.(essentially, the Insert Statement Parameters are Dynamic in that they change each time the page loads)
The Problem I am having, is that each time the page loads, I need a New DataSet, and the Page_Load is operating too quickly, changing my variables on postBack and ultimately, inserting the new values that are now loaded.
How can I:
Page_Loads > Get and Set the Variables I need > Protect Those Variables from changing on the Next Postback (so the insert statement gets the values Iwant to insert but also set and get the next ones)?
If Not Page.IsPostBack Doesnt Work for me in my Page_Load because each time the page.loads, I need those new Random Variables from a DataSet
Someone had Mentioned ViewState, but I am uncertain how to use it. I just want to protect the variables so that it inserts properly
There is button(btnOpen) and a textbox (txtResult) in the page.
Once I clicked on btnOpen, a modal dialog will appear, displaying TextBox1 and Button1.
The user is required to type something in TextBox1 and I want to pass the TextBox1.Text into my database but when I try to do that, the value actually = "", which is gone.
So I created this test program to illustrate by passing the value into a txtResult.
Can anyone guide me on getting the TextBox1.Text value?
Besides that, is there anyone to tell more about what does this lines of code do?
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The aspx code:
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the Code Behind .cs :
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I have a form that takes the user information. When the user submits the form, after the postback, I need to get all some of the textboxes in the form cleared. I tried disabling the ViewState and ViewStateMode. But both of them failed. Also tried disabling the cacheability for the page. I know I can clear the textboxes on the page load event. But I am curious to know if there is another way to do this.
View 7 RepliesPrivate Sub UpdateOffensiveStats()
Repeater losing data on postback
My app has broken after upgrading to ASP.NET 2.0. The problem is that Request.QueryString is empty when the SelectedIndexChanged event of a IE Web Controls tab strip is fired. It worked perfectly in ASP.NET 1. I have the tab strip contained within my own UserControl.
View 3 RepliesI create a class with some atributes.In a web form, I declare a public object like this.Partial Class Intencion
View 7 Repliesi use html form and html control to submit data,like bellow:
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after submit,the input email lost it's data,how to keep it?
I ve been searching for this on various forums and came through a number of supposed solutions which didnt work for me.
My web form works perfectly for me when on development and after publishing on IIS but when I try to access remotely the session value is always null.
I do these things in the following order and when accessing remotely I always get the exception i throw when session is null.
I debugged it and my list is never null when reaching the assignment point.
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in webconfig I have the following tag which I saw as an answer in many forums
<sessionState mode="InProc" cookieless="true" timeout="200" />
I have "n" <tables></tables> on my page and each <table> has One(1) <asp:CheckBox.. Enable ='true"/> and "x" <asp:TextBox Enabled="false"..>. Each Table looks as follows
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When I click checkbox, it calls javascript function and enables textboxes (I have added onclick attribute to checkbox). Page also has <asp:Button ...Text="Submit"/> whcih actually grabs the data from the textboxes on the page and send it to the databse. Here is the Onclick event of the <asp"button../>
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If the exception is thrown , textBoxes are not reset but on postback textboxes appear as disabled (values are not reset)
So here is what happening on postback when exception is thrown
1) Values are not reset (that is what want)
2) Texboxes appear as Disabled (that is what I don't want on exception, REMEMBER I enable textBoxes using client side script)
How can I keep the textboxes enabled = "true"
I have a linkbutton that displays a different record each time the page is loaded. When I first bring the page up, I can hit F5 repeatedly and the linkbutton works properly rendering a diff record each time. But in a dropdown list, or any other control that causes a postback, the linkbutton remains static, why?
In my Page_load I have
AccessDataSource1.SelectCommand = "SELECT blah FROM table where trim(recid)=" &
"'" & rndVal &
"'"
AccessDataSource1.DataBind()
LinkButton1.Text = DetailsView1.Rows(0).Cells(1).Text