I have the following code to try to use viewstate to save a variable for postback. When post back occurs the SrString value is nothing. I have set the ViewState value at the dropdownlist index chane event and set the variable equal ot ViewState("SrString") at page in the if ispostback block.
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I'm having some problems in persisting the viewstate on postback for a Control (vb.net)
here's some code i've put in my control[code]...
I'm setting EnableViewState = "true" everywhere i can, but still no result. Do i really need to set those properties here. (ViewStateMode and EnableViewState) If not, where should i handle this and what is the difference between those properties?
I have Dim a(15) as integer i wont to save this array in Viewstate .
View 2 RepliesI am trying to get the value of a Query and save it to a variable, The only way i have been successful is through creating a loop and then saving the value of the location...
Below is the
Dim DBConn As OleDbConnection
Dim DBCommand As OleDbDataAdapter
Dim DSPageData As New DataSet
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I am new at the ViewState and i am looking to see what values are stored within it. I know how to loop through an array to check for a value but i do not know how to go about doing that for a ViewState("test") property.
Let's say i have added "bob, tom, Jim" to a ViewState called ViewState("test"). I would like to be able to see if "tom" was in the ViewState("test"). If not then add it but if it exists already then skip it.[code]....
I thought I knew how ViewState worked, but I was wrong.I don't understand why the following ASPX page preserves the value typed into the TextBox after clicking on the Button?(ViewState is disabled for both the page and the TextBox.)
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I use the code below to save a textfile to a directory that should work like this[code]...
View 1 RepliesI have had a user of my VB.net web app complain he keeps getting an intermittent error message, causing him to crash out of the system.
Stack Trace:
[FormatException: Invalid character in a Base-64 string.]
System.Convert.FromBase64String(Strings) +0
System.web. UI. LosFormatter.Deserialize(String input) +25
[code]...
It appears from the error message that the viewstate keeps becoming corrupt (see screen-dump below), but I don't understand why. He claims it happens every 2-3 minutes, but I've used the system a lot and have never experienced it.I should mention too that he is using the web-app in a very "non-standard" way. To achieve optimum speed he's actually using remote desktop, to connect to our server directly, and running it as localhost. ("Madness!"- yes, I know. I didn't make the decision.) That may not be relevant of course.
Is it possible to make the viewstate false of whole page including all controls at a time.I mean I don't want to set enableviewstate="false" for all controls..In the page directive of the aspx page I have made enableviewstate="false" but still viewstate of all the controls of the is enabled.. And what the EnableViewState="False"actually works within Page directive.
View 3 RepliesI have a VB.Net web site and on my sign up page I am storing the ViewState in Session. I am using the following code to achieve this.[code].....
This has been working fine for months, then I started seeing the occasional 'System.NullReferenceException: Object reference not set to an instance of an object.'. The exception is raised when I try to get the value of the Text Property from the SelectedItem of a DropDownList, the problem being the DropDownList does not contain items after the page has posted back.The problem is only present when using IE (7 or 8 according to my logs, but I have only tested with 8), but not when using FireFox 3.5.Reverting to using the normal ViewState persistence mechanism caused the page to work in IE again.There are no ViewState related exceptions logged, it is like the page just 'thinks' it has no stored ViewState.
I agree that the best way to shorten the ViewState is to disable it on the ASP.Net controls that don't need it. Keeping it small from the beginning is a great habit.I have also heard that it is already compressed (although can be true... there are ways of compressing it even more, has described in this Stack Overflow question).
My question here is not if it should be compressed... is: when should ViewState be compressed?If we have a ViewState of 410 characters it will weight 410 bytes in a page, while a ViewState of 13.843 characters equals 13.5 KB.
13.5KB is a considerable weight already. And if I compress a CSS file that height 10KB, I think it is also worthy compressing a ViewState of 13.5KB, even if that means a little extra "thinking" on the server.
But is 410 bytes of ViewState worth the extra processing on the server?At what point is it worth compressing?
I have a form with its method being "get" that passes the variables and their values to the query string, respectively. However, it also passes the viewstate variable in the query string. Now, I have a very long viewstate value on the given page, and if passed in the query string, the viewstate variable will cause the page to error out, due to "too long of a query string" which happens to also be too long of a url.
I cannot merely remove the viewstate variable - I need it. But I need to pass the viewstate variable along via some method other than get when the form is submitted, while the other inputs of the form (the non-hidden inputs) are appended to the query string.
How do I convert the following ASP code (vb.net) to win form (vb.net)? I get a n error on ViewState.
Protected Sub TextBox_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) _
Handles TextBox1.TextChanged, TextBox2.TextChanged
IsSaveRequired = True
End Sub
Protected Sub SaveButton_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles SaveButton.Click
If IsSaveRequired Then save required.
End If
End Sub
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Using a "Numeric up down" or text box, how would i save the number the user picked to a variable and then add two to that number?
View 4 RepliesI've been literally googling for an hour now trying to find how to save variable settings to a file.I'm writing an application and I'm using alot of changeable variables. I want to be able to save these to a file so they can be loaded at application startup. I don't feel like using the regestry since I hate to write unimportant things to the registry.I remembered that I found a good example with simple code of how to do this with xml, but I can't seem to find the example now.
View 10 Repliescan i save the returning value of eval function in a variable and use it wherever i want? i can call it just in <asp: .... tags. i can't use them in vb methods. is it possible?
View 1 RepliesWhen i press the button3, i want the webbrowser change site after how mutch the clock is. Is the clock between 9:00 and 17:30, the webbrowser is gonna change to swedish sites. If the clock is between 17:31 and 21:30, the webbrowser is gonna changes to american sites. But the webbrowser is only choose ONE swedish site and ONE american site. The problem is that the variable b does not save the value it has before.How to i make so the variable b saves the value it has before? b = b + 1 is gonna be first 1. Then if i press the button3 agin, it gonna be 2. and if the value is 3, it gonna be 1 agin.
PHP
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
Dim changesSE(3) As String
Dim changesUS(3) As String
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This is the first time that I will have ever actually published a program and I have a question about when it goes into 'real use' Right now I have string variables that sets the values of a few text boxes that can be edited and 'saved' (the variable values change to the new input).
When I publish the program will these values be saved in the variables after the program is closed then re-opened? Or is everything reset when the program is restarted? And if it is all reset, is there anything internal (aka not a xml file or something) that will hold the data and keep the changes?
I keep getting the following error message when I run my vb.net web app:The state information is invalid for this page and might be corrupted.After a good search, I came across this Microsoft page, which describes the problem exactly. The likely cause seems to be "scenario 2":[code]I appear to have prevented this error from happening by using EnableEventValidation="False" in the Page node of the markup as recommended here.
View 2 RepliesI need help making this code work better. Currently, what happens is when it reloads, I loose the third value which is a calculated value . I would like for my page to reload without loosing the values for each property and each instance of the user control on the page.
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I am using VS 2008, VB and using a dorpdown listbox in my asp.net webpage. I select a value from the dropdown, click the submit button, when the page comes back from the server, the value in the dropdown is blank (default). The dropdown controls viewstate is enabled.
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I have to hide the VIEWSTATE and EVENTVALIDATION hidden fields on my ASP.net page at RUN time.
I managed to remove the EVENTVALIDATION like so.............
<%@ Page enableEventValidation="false" EnableViewState="false" %>
But the VIEWSTATE is still there and I cant get rid of it and I need to. (hard to explain why)
I have a massive viewstate hidden field that is causing my application to be unworkable. I have tried:
EnableViewState="false" on every control
EnableViewState="false" in page directive
Page.EnableViewState = false in Page_Init
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On my webpage I am loading multiple instances of a usercontrol, sometimes the usercontrol is laoded within itself. I need to save a bunch of properties for the round trip of a post back but i am confused on how to save those properties to ViewState and set them again to the repeater items within the usercontrol. have read the MSDN on Viewstate but I am not understanding it quite well for some reason..[code]
View 2 RepliesI have been reading up and trying to understand the difference viewstate and session and as i am only storing a database id i believe i have settled on Viewstate.
Am i right in saying that a viewstate never expires until the browser is closed? One of the issues i have with Sessions is that sometimes the people completling my websites forms can take and age to do so and the session can expire.
How do i convert string to raw binary and display save it in variable?
i can do it when i write the string to file :
Dim data As Byte() = Encoding.GetEncoding(862).GetBytes("שלום")
Using writer As New StreamWriter("C:lasttest.txt", False, Encoding.GetEncoding(862))
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I am trying to count how many items are in an ArrayList and then save that into a Label variable that is updated each time an item's barcode is scanned.Information about the code below:rejectedList is the ArrayList that contains rejected parts.RejectedPartsNumberLabel is the label I am trying to update with the count from the ArrayList
Public Shared Function isFault(ByRef code As String) As Boolean
rejectedList.Add(code)
RejectedPartsNumberLabel.Text = rejectedList.Count
Return (code.Length = 7 And IsNumeric(Mid(code, 1, 1))) Or (code.Length = 4 And Mid(code, 1, 2) = "NC")
End Function
1.I want my program to get the drive letter (like c:,d:) on form load and save that to a variable.What should i do to get the drive letter? 2.I want my application to fire this command (shutdown -s -p) on button click. But if i use this path (process.start("F:WindowsSystem32shutdown.exe -s -p")) to do the work it doesn't work.
The path is correct. What to do?
How can i make a program that will read a text file (.txt) and save each seperate line as a variable? e.g.
Text File:
Hello
My
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i set the datasource property of my combobox to datatable and ofcourse the displaymember and value member and now i want to take the text in the selected item aand save it into variable? i tried this
dim x as string=nothing x=combobox1.selecteditem.tostring but it is returned datarowview so what i must do??