Using VB 2005 with .Net 2.0.
I have a form which loads another form, does a little initialization, then hides itself and shows the other form. When the user finishes with the second form, it returns back to the first.[code]..
I thought it might be a timing/speed thing (somehow the server was too fast to load or unload the form), but I put a 5 second sleep between every line of code and that didn't help at all.
Protected Overrides Sub LoadForm()
MyBase.LoadForm()
Try
'StartProcess might be causing an error (error msg is issue with loading config, which would be incorrect)
StartProcess()
[Code] .....
I can run this 100 times under the exact same conditions and it seems like 40 times it will crash with the following error:
"Cannot access a disposed object. Object name: 'frmImportExport'."
It will either die on
'within StartProcess()
Dim __Delegate As New _Delegate(AddressOf StartProcess)
Me.Invoke(__Delegate)
or
Dim D As New _Delegate(AddressOf SOPERATION)
The form isn't being disposed manually anywhere that I see, and this code is being executed on formload. It's a subform that is to be displayed within a main form.
How do I re-open a form that has been disposed?I tried using GC.Collect() which did not work.I have 2 forms.The first form being the main form and the second being the secondary form. I open the secondary form with form one.Form 2 two opens and after I am done with it I close it.Now I want to open up the second form again and BAME! Error.Cannot access a disposed object.
View 4 Repliesi have a query. i created two forms a and b. if i click ok button in form a , form b should open. and i did it. but again if i click the button it says that i can open a form once it is disposed.
View 1 RepliesIf TextBox1.Text = "Welcome!" Then
MsgBox("Welcome!")
Else
MsgBox("Error!")
Me.Close()
End If
I receive "Cannot access a disposed object (Form1)" when the error arrives.
I'm having a strange difficulty. Here is the order of events:User presses button on form1 New Form object is created for from 2 New form object '.show' command is fired Form 2 opens correctly In the Load Event of Form 2, the form attempts to do various things in a try, catch, finally clause On catch, I close form2 down '.close' as it cannot be used as something has gone wrong with the execution However, my problem is this. It is acceptable for things to go wrong on the from 2 load event which is why I have implemented the try - catch functionality. However, when I close the form2 down as a result of the problem, a real error ocurrs 'Cannot access a disposed object' and the VB IDE refers me to Form1's '.show' event for Form2.
It is almost as if the form hasn't fully 'shown' before I am closing it down. Does anyone have any idea what the problem is here? Do I need to close down Form2 ourside of it's Load event handler so that Form1 thinks it has loaded correctly?
By default my app loads the activation form. On the form load it checks if the license is valid and if so i want it to close/hide the registration form and open the form that starts my app.
When i try to do this it crashes my app with the following error
Quote:
Cannot access a disposed object
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'check if a valid license is available
[Code]....
When try to open in design mode a form (VB.NET), in which I have a custom UserControl, I see the message from Visual Studio:
Microsoft Visual Studio
The control MyNamespace.MyUserControl has thrown an unhandled exception in the designer and has been disabled.
Exception:
Cannot access a disposed object.
Object name: 'SplitterPanel'.
Stack trace:
OK
And the form is not displayed in designer. What to do?
I am trying to write a program that takes the input of a CSV file, makes modifications, and prompts the user on how to handle certain modifications.
I have the parsing of the CSV file complete, the handling of most of the string manipulation down, and the user interface complete, except when it comes time to move onto the next record.
I had it display the form as a modal dialog, and used me.hide() once it was over to continue with the program. However, when it gets to the next ShowDialog(), it says that the object has been disposed! I've tried a modeless dialog, with a while loop that waits for a boolean to be flipped by a button on the dialog being clicked, but that, as predicted, did not turn out so well and just shot the processor load to 100%.
One thing I notice in looking around is that I have everything based on the "home" form, the initial one that comes up when the program is run. Is this incorrect coding? Does this require the prompt being on a child form?
i am facing a huge problem with the "Cannot access a disposed object. Object name: 'TreeView'." error.
On a windows forms of mine i use a custom windows explorer object.
And here come the code parts...
On the selected node event, i load the images found within the selected directory to the FlowLayoutPanel.
Private Sub ExpTree1_ExpTreeNodeSelected(ByVal SelPath As String, ByVal Item As ExplorerControls.CShItem) Handles ExpTree1.ExpTreeNodeSelected
'Loop until all images are loaded.
LoadImagesToFlowPreviewPanel()
[Code]....
I found an error - cannot access a disposed object in my project.
i using vs2005.
but before this, i using vs2003 and this error doesn't occur.
but when i convert to vs2005 and debug, this error occured.
I have a windows form in .NET that will serve as a wizard to achieve something. This contains 3 steps: Step1, Step2, Step3.
Each step is again actually a user control. Main form contains a panel that display the current Step. When I change among steps then:
1) Dispose the current user control by calling its Dispose() method.
2) Clears the main form panel
3) Initialize the user control of next step and add it into the main panel
Now, the issue is, User control of step one contains one more user control. When I change to another step and come back to step 1, I get following error:
"Cannot access disposed object."
Because I have to first dispose the user control before actually displaying the another step. And when I come back to step 1 and tries to open the user control on step 1, it gives the aforementioned error.
"Sometimes your code requires an unmanaged resource, such as a file handle, a COM wrapper, or a SQL connection. A Using block guarantees the disposal of one or more such resources when your code is finished with them. This makes them available for other code to use. Managed resources are disposed of by the .NET Framework garbage collector (GC) without any extra coding on your part. You do not need a Using block for managed resources."
So, which unmanaged resources must disposed manually and which disposed automatically of by the .NET Framework?
I tried running code analysis the first time and found what it appears many others on SO doing the same have found: an abundance of
In method 'SomeMethod()', object
'SomeObject' is not disposed along all
exception paths. Call
[code].....
[code]in this code, do the objects con and cmd get disposed because the return statement is placed before the end using statement.
View 1 RepliesMy program involves accessing a print preview dialog.
It works just fine the first time. However, when I close the printpreviewdialog and then try to open it again (through the button) in the same run
then I get a "cannot access a disposed object" runtime error. Hence, it can only work once during a program run.
I just installed VS 2010 Ultimate Beta2. installation was successful. When I perform the scenario of (File --> Open -- > New), I get that error message.
Error message "Cannot access a disposed object. Object name: 'MarshalingWindowFrame'."
Invalid usage of Disposed Object - find which object is open or I am trying to access
View 10 RepliesI seem to be getting a random abject disposed exception.Sometimes it occurs when I move from 1 form to another, sometimes it happens when a timer activates.It says the object name is "". How am I supposed to look for an object called nothing. I'm using vb express 2010 on windows 7.
Code:
System.ObjectDisposedException was unhandled
Message=Safe handle has been closed
Source=mscorlib
[code]....
I'm attempting to run different tasks in there own processes, waiting until each is done while keeping the UI responsive. So far it works exactly how I want it until I try to reuse some of those processes....here is a sample of the
Private WithEvents TaskOneProcess As Process
Private WithEvents TaskTwoProcess As Process
Private WithEvents TaskThreeProcess As Process
[code]....
This is a over simplification of what's going on but it gets the point across. So it works exactly as expected, a button is pressed and the sequence starts. As each task gets disposed it recalls the StartFixing statement which then calls the next one in order until they are all done. BUT when I go to do it a second time the Disposed never fires assuming since it's already disposed. How do I recreate the same named process so it can be reused and still have it fire the disposed event?
I'm getting this error over and over again when I click the cross button on the main form which is a MDI parent form. How can I fix this error?
error:Cannot access a disposed object.Object name: 'frmmain'.
I am using the following codes:This code triggers my transport sequence. I am not having any variable sequences.
[code]...
What is going wrong? I reach the error at the first instance of "transport.Show()"
I got the error having the stack trace...
System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'Button'.
at System.Windows.Forms.Control.CreateHandle()
at System.Windows.Forms.Control.get_Handle()
[code]....
It doesn't give error when I just switch the order of the .show and .close method
Friend Sub GoHome(ByVal sender As Form)
InTransit = True
fMain.Show()
sender.Close()
End Sub
why for the first case it gives error and why in second case it doesn't?
I am having trouble trying to figure out why I'm getting this warning in following code.
CA2000 : Microsoft.Reliability : In method 'Encryption64.Decrypt(String, String)', object 'des' is not disposed along all exception paths. Call System.IDisposable.Dispose on object 'des' before all references to it are out of scope.
[Code].....
This is a question I have asked myself many times in the past as I nested using statements 5 deep. Reading the docs and finding no mention either way regarding other disposables instantiated within the block I decided it was a good Q for SO archives.
[Code]...
I got the "infamous" 'Cannot Access Disposed Object.' error when I was attempting to open a form again after I had closed it. The fix (even though it's annoying), is easy enough; but again it's managed code problems and weirdness I still haven't changed my opinion that I won't be using MS .NET after this when I get my development box back to normal. BUT anyway the solution is self explanatory and very easy (and somewhat obvious) [Code]
the Application hiccups with a very nice message, after you close the form down and try to reopen it, that says: Cannot access Disposed object. So, my thought is that the "IsDisposed" property runs some sort of function to determine the Garbage Collection state and does a collection, or updates the request for the collection to be done.
I am using VB 2008 Express Edition.I have an app that has 2 forms (will be adding more). Button click on form1 opens form 2. The first time I run my app everything works fine, but when I click the close 'X' button on form 2 and try opening form 2 again by clicking the button on form 1, VB throws a Object Disposed Exception, Cannot access a disposed object.[code]
View 13 RepliesI am trying to send E-mails asynchronously and it works fine as long as there isn't an AlternateView attached to the e-mail. When there is an alternate view, I get the following error:
Cannot access a disposed object. Object name: 'System.Net.Mail.AlternateView'
System.Net.Mail.SmtpException: Failure sending mail. ---> System.ObjectDisposedException: Cannot access a disposed object.
[code]....
I am getting the following Exception when calling MyBase.Dispose ()ObjectDisposedException was unhandled.I tried adding a Try Catch around the call but it doesn't catch the exception.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Dispose()
[code]....
FYI: The value of disposing is False
I am have an exception when I run the following code :
Private Sub MainMenuForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Try
'Save the Sum of the Existing "Excel" Processes:
For Each Proc As Process In Process.GetProcessesByName("excel")
[code]....