I have a dataset returned after executing a sql query. below is my code to access the returned dataset and I seem to get this error sometimes and not all the time this code executes
Private Sub Timer1_Elapsed(ByVal sender As Object, ByVal e As System.Timers.ElapsedEventArgs) Handles Timer1.Elapsed
Dim currentMethod As String = MethodBase.GetCurrentMethod.Name
[Code].....
I'm getting a Collection was modified; enumeration operation may not execute error every time I try to close this form. I suspect it has something to do with the StringBuilder() which I have declared in the starting form (Details1). I have already spent hours looking for the problem. It does not throw an error when I debug, only when I install on other machines.
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I have some code that i cant work out why its happening and how to fix it. What im attempting to do is loop through the controls in a gridview and replace it with another control along with the text
Dim i As Integer
Dim row As GridViewRow
Dim rowCell As TableCellCollection = row.Cells
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We have some third party code that is causing some misery at the moment due to throwing the above error: it is slightly odd because it is an intermittent error. Here is the method that is causing the issue:
Private Shared Sub IntLocateDictionaries(ByVal haystack As ExpDictionary,
ByVal needlearray() As Object, _
ByVal resultarray() As Object, ByVal removemarks As Boolean)
Dim i As Integer
Dim item As Object
[Code] .....
I understand that this error is usually caused by trying to modify a collection whilst enumerating around it, hence why I've added logging on the only line that looks like might alter the collection... Since adding the logging we have still experienced the issue but NO LOGGING appears: this isn't surprising since if you look at the parameters on the calling line (the only place this Sub is called from) - removemarks is passed as False - this will be passed all the way down through the recursive calls and so that line which calls .Remove never gets executed....the fact we don't see logging proves this....
I am working on a project where I have a personnel class. The records stored in the class are populated a few records per second. At the time I am inserting the records, I have to check the same class to ensure the same record is not added twice. Since I am looping through the class using "For Each", I get a message "Collection was modified; enumeration operation may not execute".
View 5 Repliesi'm getting the following error: "COLLECTION WAS MODIFIED; ENUMERATION OPERATION MAY NOT EXECUTE."
The stack trace is ;
at System.Collections.SortedList.SortedListEnumerator.MoveNext()
at SatcomDiscoverySocket.clsGatewaySend.SendViaGatewaySend() in C:Documents and Settingsjim.SATCOM_DOMAINMy DocumentsVisual Studio 2005ProjectsSatcom Discovery Socket ServerSatcomDiscoverySocketSatcomDiscoverySocketThread PollingclsGatewaySend.vb:line 60
The line in question is but I don't believe that to be true I think its the line above it;GatewaySendEntry = Nothing The code is below. I can't figure out why, it's causing the error at that line and how to fix it.
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I have this flood-fill algorithm, based on a queue (I tried the recursive method but pictures are too big and it was causing stack overflow).The problem is that when it makes the second pass in the for-each loop, the program crashes and compiler gives me the message "Collection was modified; enumeration operation may not execute.".Well, of course I know the collection was modified (it supposed to be!) since I am adding necessary items to it on-the-fly within the loop. What I cannot understand is why it happens since the for-each is based on the remaining items in the collection and not in a numeric index.
Below, the actual code:
Code:
Public Sub FloodFill(ByVal myx As Integer, ByVal myy As Integer)
Dim icoord As coordinate
Dim ocoord As coordinate
[code]....
This is what happened: on the form load of my application i created a background worker to bind collection (records from database filled in the dataset) on my control. but the problem is when the i updated the records on the database it throws an error if i run this procedure again.
If xControl.InvokeRequired Then
Dim MyDelegate As New InitializeDataBinding_Delegate(AddressOf InitializeDataBinding)
Invoke(MyDelegate, New Object() {xControl, xQuery, xPrimaryKey}) ' ERROR HERE SAYING: Collection was modified; enumeration operation may not execute.
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I am encountering an error when looping through datarows. I searched SO and tried the solutions, but no luck. Collection was modified; enumeration operation might not execute.
Dim dRow As DataRow
For Each dRow In dt.Rows
dt.Rows.Add(dRow("CustNum"), dRow("SalesRepName"), dRow("mgrid"), "=""" & dRow("midValue") & """", dRow("dba"), dRow("sysDate"), dRow("statusID"))
Next
The error occurs the first time the code hits "Next". What would be causing Collection was modified; enumeration operation might not execute.How can I resolve this error?
I have a multithreaded app that is throwing the following error.Collection was modified; enumeration operation might not execute.[code]I'm pretty sure the collection is being modified by another thread. I attempted to fix the problem with the SyncLock's but clearly I'm missing something here.I thought I could lock the object by properly using SyncLocks, am I just not locking the right object(s)? Or am I completely missing something here.Besides using SyncLocks what other options do I have to prevent this error. I was thinking perhaps a global variable to keep track critical code sections so that no 2 threads enter.I'm also a little confused about what collection is being modified my first guess was CLResultsDataTable. ResultsDataTable, but I'm not sure.This is an older project I just recently picked back up so I'm still stepping through a lot of code to try to figure out how/why this is happening
View 3 RepliesI'd like some help with this error that other users has when they launch the app I created. I will copy / paste the error
Tittle: Collection was modified; enumeration operation may not execute.
Error:
System.InvalidOperationException: Collection was modified; enumeration operation may not execute.
at System.Windows.Forms.Control.MarshaledInvoke(Control caller, Delegate method, Object[] args, Boolean synchronous)
at System.Windows.Forms.Control.Invoke(Delegate method, Object[] args)
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have a form onto which i've place a menu item called Exit. When I click the Exit, i expect it to close the entire application.Here is the code
Private Sub mnuExitApp_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnuExitApp.Click
Application.Exit()
[code].....
I'm getting this error when I deploy a VB.NET application and for the life of me I cannot figure out why.I do not get this error when I run the app from the IDE and the test machine I am deploying it to has a similar configuration to the dev machine...Windows 7 & .NET 3.51 SP1 and 4.0.The app bombs out when the main form is loaded after logging in. I've narrowed it down to the main form because if I load another form from login and then open the main form, this happens.
View 1 RepliesI realize this has been covered a million times before but with threading sometimes a problem is app specific. I have a multithreaded app that assigns a url to a thread which it then fetches and crawls. Now the function where I collect each threads items I have added synclocks assuming this would avoid alterations. But I get the "collection was modified, enumeration operation may not execute" error. look at my code:
For Each landingPage As String In landingPages
'logger.constructLog("Working on landingPage link: " & landingPage & " at " & DateTime.Now.ToString, True)
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I have a form with a listview, and it operates as I expect it to, but when I close the form the debugger stops on the me.close() method and pulls up the collection was modified;enumeration operation may not execute error. this occurs even when I do nothing in the program and just try to run and close it.
View 8 RepliesWhen I close some of the forms I have opened in my project, i get an error that says "Collection was modified, Enumeration operation may not execute"I used a Try/Catch error handler on one of the forms and it stopped the error from popping up, but I want to know what I can do so that this does not keep happening.
View 6 RepliesI have the following classes:
Product, Service and OrderItem
Product and Service must inherit OrderItem. So basically I want to store OrderItem object in my shopping cart and these object are store in a list.
Public MustInherit Class OrderItem
Private m_enuItemType As TypeOfItem = TypeOfItem.None
Private m_strUserID As Integer[code].....
I have a logout menu option in my MDI application. On log out I want to close all open forms. currently i am using following code snippet to achieve this;
For Each f As Form In My.Application.OpenForms
If f.Name = Me.Name Then
For Each child As Form In f.MdiChildren
[code]....
It is working perfect in my test environment, even though I expected For Each loop will throw "Collection was modified; enumeration operation may not execute" exception. since on each child form Close() calls, f.MdiChidren collection get modified, that surprised me a lot. Can anybody tell me why it's not throwing that exception?However it throws "Collection was modified; enumeration operation may not execute" in a client system.
I've looked around at other forums and have seen that this is thrown because I am adding items to a collection in a for each statement. If I understand that right, I need a different way to populate my combobox here's the code.
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This gets a list of all of the Shafts in the DB. I only need the name of the Shafts to be loaded into the combobox. What can I do to accomplish this without modifying the collection?
I have an application that I've tested on multiple machines. It runs perfectly on the development machine, but no others. I have itextsharp.dll included and registered in the installer (I used NSIS). On one of the other machines, this was retrieved from the system log:
Application: Evaluation creator.exe Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.InvalidOperationException
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please i have this exception in my project which i do not know how to solve it.The problem i think is not from my codes but it is from a tool box item i am using which is giving me that error if i delete that tool box item from my form this exception is not thrown.The item name is GrFingerXctrl class. This item will enable me to integrate a biometric fingerprint reader in my application.it is from an SDK i downloaded from [URL].
View 1 Repliesi have a datagridview that show an access database also there is toolstrip menu i defined the datasource and everything is fine except that when i run the application and edit anything and when i press the save button on the toolstrip an error appear and highlight this: Me.TableAdapterManager.UpdateAll(Me.My_phone_numbersDataSet)
and the error is: invalid operation exception was unhandled
Keep getting a exception when I click one save.
"Invalid Operation Exception was unhandled"
Basically it just needs to save all my text in my text boxes in a XML document.
Imports System
Imports System.IO
Imports System.Xml
Imports System.Xml.Serialization
<Serializable()>
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Got a proccess thread thats in charge of loading a listbox full of the first line of text for richtextbox items on form load. Though I use Me.Invoke(New MethodInvoker...) to add items on the main thread so its thread safe it coughs when the first line of rtf data are thrown at it, acting as if I hadnt called adding the items on the main thread.
Up at the class level:
Dim Worker As System.Threading.Thread
In the load procedure for the form:
Worker = New System.Threading.Thread(AddressOf WorkerDo)
Worker.Start()
[Code]....
I"ve also tried to remedy this using a delegate to invoke the listbox before attempting to update it, but the invoke method itself is throwing the exception. I am not using the default instance of the form (a new instance of this form is created). Anyone know how I can get around this? I can't load the listbox full of items directly in the form's load procedure because work takes place in the thread beforehand so there are strings to add to the listbox. I've got MS Visual Studio 2008 Pro and Vista SP2 (latest updates applied).
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MS has a patch for the OnListChanged event handler issue, even though it seems we have to pay to have access to it. This fix specifically addresses an error message when you press ESC to cancel adding a new row in .NET 2.0: [URL]
FIX: Error message when you try to press ESC to cancel adding a new row to a DataGridView control in the .NET Framework 2.0: "An unhandled exception of type 'System.InvalidOperationException' occurred in System.Windows.Forms.dll"
Any thoughts on what might cause a thread error like this?Error:InvalidOperationException was unhandledCross-thread operation not valid: Control 'Form1' accessed from a thread other than the thread it was created on.
Relavent Code:
Private Sub SerialPort_DataReceived(ByVal sender As System.Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
[code].....
I get that error any time my form closes(Me.Close), even if I don't do anything to the form at all exept load another form like this: Form2.Show Me.Close().
View 8 RepliesI have this as my transactions code and I'm having an error connection closed . Iv tried fixing it with odb.open but i dont know where should I put it
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tems to a listview from a worker thread using a delegate and invoke, but I'm unable to just loop through the listviewitemcollection.Here's what I'm doing:
...
Private Delegate Function getListViewItemsDelegate() As ListView.ListViewItemCollection
Private Function getListViewItems() As ListView.ListViewItemCollection
[code].....
I have just received an interesting feedback from a VB.NET customer using our product - for some reason intellisense hidden a certain enumeration value.After a small testing I have found that this is likely a bug in IntelliSense: [URL]..To be honest, I did not expect this problem with such a basic stuff like this. Have you seen this in the past? For me, it doesn't work in all VS versions...
Anyway, feel free to track this issue if you are coding in VB.NET.