State Management :: Textbox Loses Its Value After Postback?
Oct 18, 2010
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?
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.
In my page, I need to enable a text box when user click on check box(checked). I have used javascript for this. It works fine but when there is postback for the page, the textbox becomes disabled again although the check box is checked. But the value in textbox still appears. Is there any method to retain the enabled state for text box on postback other than using hidden values?
I 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.
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!!
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.
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
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.
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.
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
[Code]....
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../>
[Code]....
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)
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
My dropdown controls do not keep the values after postback even though their EnableViewState is = true and in Page_Load I fill my controls ONLY if not postback.
My controls are inside a panel and the panel's EnableViewState is set to true as well...
To see the page you can log in as test and password is 12345
click on search page and set a value to say Gender and Ethnicity and click submit.
You will see the results, then navigate to number 2 or 3... You will see that it refreshes the controls and sets them to default.
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?
Im currently experincing some difficulties with the viewState. The scenario is that i have a datagrid that has a column of buttons that when pressed will store a value in the viewState. I have already done this on one occasion in the same page, but for some reason the second item in the view state is always returning null, even when i hardcode in a number in before the postback. Im at a loss as to why this is happening, anyone expericened this and know what is wrong.
EDIT: Ive found out the cause, Its due to when you click a button in a data grid it does the postback code first, then fires the event handler, so of course the view state would be empty as it is coded to be set in the event handler for the button click. Is there any way to avoid that? So the event code is fired before the postback code?
i have created a user control UserControl.ascx, in Code behind file of UserControl.ascx i have created an object of a class MyClass.cs,
Like
if(!Page.IsPostback) { objMyClass= new MyClass(); }
but when i click on button of UserControl.ascx page and try to access objMyClass object then it set as null, so how to persist MyClass object when page PostBack, i wanted to keep object persist till the user access the page, when user goes out of this page then object should distroy?
This is quite simple. When I press btn1, it sets correctly the Session Key. And this is then the issue arrives: When I press one of these buttons, this is the sequence of what happens:
So, everytime there is a PostBack, even before the Page loads, the session starts and generates a new Id. This way, I loose everything during the PostBack. My Session State configuration:
[Code]....
This is running on VS 2010 + V3.5, on IIS5.1. The Page header configuration is default.
I have created a user control with a property named CurrentPage. When a link button is clicked it runs PostbackToPage() and passes a command argument in which then sets the CurrentPage property with this new value. On the page which uses the user control I am trying to display the updated CurrentPage property after a postback. When I click the link button to cause the postback the CurrentPage is the default value. However when I click it again it works as expected. So it seems to only work after 2 postbacks. How can I get this to work after the first postback?
While generating dynamic controls like , textboxes, dropdownlist, checkboxes and radiobuttons, after filling the textboxes and etc and submit and then postback occurs, the dynamic created controls missing. I try to find a way to make the controls persist for validation checking. Tried to use Viewstate to store the pnlTextBoxes and etc, but it has serializable error.
I do some dynamic stuff with UpdatePanel controls and it would be great to store stuff in a Session key and be able to grab it immediately with confidence in a Page_Init. Fantasy e.g.,
I want something like this so that even if an individual user has two or more instances of that page open I am able to respond correctly to the immediate instance in Page_Init. Is it possible to achieve what I want or some facsimile of same? I know I can speculatively make an assumption and then check it in Page_Load when I have access to ViewState, but I would like something that approaches a best practice.
