VS 2010 AccessViolationException - .DoEvents
Apr 9, 2011I have a simple loop that "sleeps" a thread..Out of nowhere i will get this error below, it could be 1 minute, 20 seconds, 5 seconds, all at random times...how to fix it?
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VS 2010 AccessViolationException?
Mar 18, 2011I bumped onto another little problem during my project,the problem is as following:I have a project with multiple forms. My startup form is Form1.On Form2 I have a button that calls the open file dialogue (ofd)When I try to open it I get a " AccessViolationException *Attempted to read or write protected memory. This is often an indication that other memory is corrupt.*Now the strange thing is that,when I place a button for the ofd on my form1 ( my startup form ) the dialogue does open and it doesn't crash.If I after first opening the ofd on form1 continue to form2 the ofd works there aswell.I've been tracing this problem down as good as I can and I found out that the ofd doesn't work anymore after I read data from a DB ( access )
To show you what I mean I'll type the code I used for the DB reading here:
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VS 2010 Marshal.ReadInt32 -> AccessViolationException?
Jan 11, 2010VS 2010 [RESOLVED] Marshal.ReadInt32 -> AccessViolationException
View 6 RepliesVS 2010 Random AccessViolationException's Since Upgrading?
Mar 2, 2011We recently upgraded VS 2005 to VS2010 and converted an application seemingly without any problems. But when deployed to the customer they are getting intermittent errors at seemingly random places in the program which force the application to close and AccessViolationExceptions being logged to the Application Event Log.
The customer's site is a multi user environment with the application hosted on a server and users running the app via RDP. We get two errors in the event log:
Application: ContainerDepotSystem.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.AccessViolationException
Stack:
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VS 2010 An Extra Click To Get Out Of A While Loop Using .DoEvents() ?
Mar 15, 2012I wrote a small API gui to communicate over foundation fieldbus.I've used a While loop that constantly reads some parameter values from the bus. At the end of the While loop, I put Application.DoEvents()so that I can use another button to stop the reading process. It all seems good and easy.. but there's one problem: when I get the While loop running and wish to stop the process, I have to first click somewhere on the form, anywhere, before I could click any buttons(either 'stop reading' or 'reset' button mostly). That extra click makes my form seem unresponsive and lame.I wonder whether this is a problem pertaining to DoEvents() or my use of Foundation fieldbus.
View 1 Replies.net - System.AccessViolationException?
Oct 8, 2009I am using a com DLL in the following manner:
#Region "API Function"
<DllImportAttribute("abc.dll", EntryPoint:="optcntl")> _
Public Shared Function optcntl(ByRef pBlocks As blocks) As Integer
End Function
#End Region
This DLL using the other four dlls to complete its processing. If I change the current directory path from the /bin/ folder to other folder in C or D drive which contains all the DLL. I get the following Error message: System.AccessViolationException: Atempted to read or write protected memory. This is often an indication that other memory is corrupt
Get AccessViolationException With A Code?
Aug 16, 2010I get AccesViolationException with a code when I try to send a packet back to a server. I tried another way with my packet sniffer dll, there I get a SEHexception.Here is my code I used where I get the AccesViolationException:
Public Declare Auto Function vpSendPacket Lib "VBPCAP.DLL" (ByRef packet() As Byte) As System.Int32
Public Sub sendpacket()
Dim str As Object[code]....
I think the program I'm trying to send to is protected.
AccessViolationException With Shell To Explorer
Dec 15, 2010I wrote a backup utility that synchronizes a list of folders. Errors appear in a list. In the list I can right-click to retry, exclude the folder next time, or open the folder in explorer to examine.When I shell to explorer I get an AccessViolationException. Form1 opens Form4 with Form4. ShowDialog(), and that's where the error occurs. The error does not occur within Form4 where the shell function is called. memory must be getting trashed somehow.I've used two methods, Shell and System.Diagnostics.Process.Start. Each produces similar results. Shell waits awhile before causing the error, but Process.Start causes the error immediately.This is VB.Net 2010 using framework 4, though I did resolve a shell problem once before with VBA by writing out a VBScript file then shelling to the VBScript file.
View 3 RepliesAccessViolationException With Shell To Explorer?
Dec 15, 2010I wrote a backup utility that synchronizes a list of folders. Errors appear in a list. In the list I can right-click to retry, exclude the folder next time, or open the folder in explorer to examine.
When I shell to explorer I get an AccessViolationException. Form1 opens Form4 with Form4.ShowDialog(), and that's where the error occurs. The error does not occur within Form4 where the shell function is called. Memory must be getting trashed somehow.I've used two methods, Shell and System.Diagnostics.Process.Start. Each produces similar results. Shell waits awhile before causing the error, but Process.Start causes the error immediately.
This is VB.Net 2010 using framework 4, though I did resolve a shell problem once before with VBA by writing out a VBScript file then shelling to the VBScript file. I don't think the process being started is isolated enough. It's sharing memory or something else.
MSHTML System.AccessViolationException?
Sep 21, 2006I seem to be in a quandry over an error that makes no sense to me.In following some examples I have found on the Net, I've been attempting to use the MSHTML library in vb.net to access the HTML DOM.[URL]...when I look at the error message, it tells me that memory could be corrupt elsewhere. I've attempted this line of code by omitting the "http://"portion of the URL, byt trying numerous web sites, and with various other arguments in the 2nd parameter, such as "", ControlChars.NullChar and "null". I've also reset my PC and created a brand new application with only that code and get the same results.I am using VS.NET 2005,version 8.0.50727.42I don't know if it will help, but the details from the exception object are as follows:System.AccessViolationException was caught Message="Attempted to read or write protected memory. This is often an indication that other memory is corrupt." Source="mscorlib" StackTrace: at System.RuntimeType.ForwardCallToInvokeMember(String memberName, BindingFlags flags, Object target, Int32[] aWrapperTypes, MessageData& msgData) at mshtml.HTMLDocumentClass.createDocumentFromUrl(String bstrUrl, String bstrOptions)at MSHTML_DOM_Practice_1.Form1.createDoc(String URL) in D:Dev V.2Misc practice projectsMSHTML DOM Practice 1MSHTML DOM Practice 1Form1.vb:line 19I,
View 3 RepliesSystem.AccessViolationException While In Loop
Jun 16, 2010Here is a part of my code which loops through the items in a checkedlistbox.. The text of each item is the name of a computer.When the loop runs for the first time, it runs fine, but when it goes through the loop the second time I am getting the following exception:Attempted to read or write protected memory. This is often an indication that other memory is corrupt..The code connects to wmi and retrieves the time zone information from the registry.. It is given below: [code]' then there are lines of code which does something with 'lngTZBias..So, if the checkedlistbox has only one item checked, the code runs fine.
View 1 RepliesWhat Can Use In Replace Of The DoEvents() In Vb6
May 23, 2005I am using ASP.NET and was wondering what i can use in replace of the DoEvents() in vb6?
View 5 RepliesWhat's The Equivalent Of The VB6's DoEvents In .NET
May 4, 2009What's the equivalent of the VB6's DoEvents in .NET?
EDIT:I have a Sub that takes a long time to do its work. (it has a do-while) when I call it, The form turns white. in VB6 I used to put a DoEvents in the method (inside its do-while) to prevent this.
AccessViolationException Error When Trying To Interface With Third Party Dll?
Dec 28, 2011The error message that I've been getting for the past few months when trying to access functions of a specific third-party .dll using vb.net is this: "An unhandled exception of type 'System.AccessViolationException' occurred in test.exe Additional information: Attempted to read or write protected memory. This is often an indication that other memory is corrupt."
I've been researching this error message, and I have come to know that it is likely due to either attempting to access memory that isn't available or due to "enhanced" security features.I am trying to access a third party .dll. The functions in that .dll all deal in one way or another with Handle types (either returning them or accepting them as parameters). I understand that handle's can be essentially pointers to pointers (pointing to an entry in a memory table, which is itself a pointer), and I also understand that handle's don't, strictly speaking, exist in the .NET framework, but I do understand that through some combination of IntPtr's and possibly the Marshal class, they can be dealt with.
I don't believe vb.net's lack of a Handle type is the problem, because the dll function that I am calling, which on success returns a handle, returns a number <= 0 if the ip address it is searching for is not found, and the ip I specified doesn't exist. Also, the error really only occurs when executing the code from within the the Visual Studio environment. I compiled the executable and ran it 77 times(literally), and I only got the error on the 77th try.
I'm trying to find out all I can about this error. I would like to completely eliminate it. Could the error come as a result of something happening within the dll itself? The function asks for an ip address, and the ip address I have specified doesn't currently exist on the network, but as far as I know, the function handles that by returning a number less than or equal to zero. I am very confused as to what the problem could be. I have successfully interfaced with .dll's before. I've read about the hotfix for .NET 2.0 regarding this error message,but I'm a little skeptical. I've tried everything else I can think of, though, so I may give that a shot.I'm 100% certain that:
-I am calling the correct function within the .dll
-I am using a signature that matches the signature of the function
-The error has nothing to do with User Account Control.
The code is very simple to try to isolate the issue:
Imports System.Runtime.InteropServices
Module test
<DllImport("3rdparty.dll", EntryPoint:="#12")>[code]......
AccessViolationException Was Unhandled - Calling Fortran Dll
May 27, 2010I have a subroutine that was written in fortran that I need to call from VB.NET where all of my other functions are written. I did not write the fortran, and hardly know fortran. I am getting the below exception on my dll function call and don't know how to fix it. I wonder if it is due to incongruent variable lengths? I have the source for my fortran and compiled it using the g95 compiler. I have tried compiling it with a flag on which is supposed to force all of the reals to 32 bits (-r4). It weirds me out that you don't seem to be required to initialize variables before use in fortran. I thought it was supposed to be a ridged language.
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C++ - Unhandled AccessViolationException Error Calling A DLL?
Oct 6, 2011I'm trying to call a C++-compiled DLL from VB.net and I'm running into some problems. Seems like there's an obvious solution, but I can't figure it out.Here is the function declaration in C++:
MyFunction(int trailingaveragesize, double sigmasize, int myflag, int sizeSeries, double *Xdata, double *Ydata, int sizeinputparameter, int *averagePairs, double *PositionsSize, double *PnLSize)
Here is how I'm calling it in VB.Net:
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System.AccessViolationException Happen Because Of Faulty RAM?
Sep 18, 2009I have a website that i've been working on for about a year now.Recently, it's started throwing System.AccessViolationException every now and then, in my dev machine, mostly, when I was away from the machine.I haven't changed anything on the server code in weeks, since I've been working 100% on the Javascript part, and this error started appearing recently.
Also, the code I'm doing is 100% managed. I'm not doing any interop, calling strange DLLs, nothing. It's pure VB.Net, so I don't see how I could be generating one of these myself.Now, I've been using this new machine for a couple of months, and it's not working 100% right. Every 2 or 3 days I'm getting a blue screen for example. I haven't had time to diagnose it properly, but I'm suspecting I may have a faulty RAM chip.
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VS 2008 AccessViolationException When Using Marshal.Copy
Dec 24, 2010I get an AccessViolationException using this code (attempted to access protected memory, this is often an indication that other memory is corrupt) on the line in DoWaitNotify that copies the pixel data back to the location in memory. In my experience, that usually means that the array is too large, but it all seems to check out. Does image data expire after a certain time or something?
Public Class Form1
Private Const NUM_THREADS As Integer = 3
Private Original As Bitmap
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Application.DoEvents Alternative?
Jun 6, 2011Any good alternative to using DoEvents in VB.NET
View 6 RepliesHow To Cancel BackgroundWorker In WPF Without DoEvents
Jun 2, 2011I have a search box that works great in WinForms, but is giving me trouble in WPF.
It works by starting a search each time a letter is pushed, similar to Google.
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Application Hangs On Call To Doevents?
Dec 22, 2010I am re-posing this question because the prior post has gotten really full of side issues so I fear the main problems has been lost.I have a windows forms application written in VB.NET which scrapes information from serveral web pages? I am having problem with one particular site where partway through the page navigation my application hangs. When I press pause (or break) in the debugger, it stops on a call to System.Windows.Forms.Application.DoEvents.
View 7 RepliesCommand Of DoEvents In Program 2008?
Mar 16, 2009What is the command of DoEvents in VB2008?
in VB6 when I was doing a loop I wrote DoEvents in the loop to continue with other events.
Does DoEvents Affect Only Current Thread?
Jun 7, 2011I have a simple 'Working' form that runs on its own thread to keep the user informed that the application hasn't died during long running operations. In order to get the working form to update I had to insert a DoEvents() call. I'm curious, will this only pump messages for the current thread I'm in, or will it do it for the whole application? I would prefer that the main window stay unresponsive till the operation finishes. Just to be clear, I'm fine with the code I have, but I would like to know how DoEvents() behaves with threads.
Below is the code for the working form.
Public Class frmWorking
''' <summary>
''' Creates and starts a new thread to handle the Working Dialog
''' </summary>
''' <returns>The thread of the Working dialog.</returns>
[Code] .....
Exit Out Of Application.DoEvents() Loop?
Dec 15, 2009how to exit out of the Application.Do() as i am hanging in that .Here is a sample of my code.
Imports PDFCreator
Imports System.Windows.Forms
Public Class Form1
[Code]....
Hooking In To Application.DoEvents Method
Jul 25, 2009I am not very familiar with VB.NET so I don't know if this is possible.Some code I am working on is setting the properties of a very large class. In the setter of each property an event is raised to indicate that the class data has changed. An event handler then serializes the instance of the class to a database.Obviously I do not want this to happen after each property is set, so I need to either have a delay before saving, or something else.I am keeping a large list of instances in a cache implementation already, so one option would be to only process the cache every now and then and save all unsaved instances in cache to the database.So I tried to see if I could derive a class from Application (and override DoEvents), but it is NotInheritable, so no luck there.
View 3 RepliesNet Not Responding, Application.DoEvents And Threading?
Mar 8, 2009My mdi VB.Net application performs a long operation on some data. Ideally I should use a separate thread to prevent the dreaded "Not Responding" message.My problem is if I use a separate thread users then have the ability to click on other controls in the application which can directly affect the operation my background thread is working on, creating an error.
Is there any way to prevent all the mdi windows, toolbars and other controls from receiving mouse clicks and keyboard input during my background thread's operation?
Or is there a way to clear the message que before performing a Application.DoEvents?
VS 2008 Unable To Use An Application.DoEvents?
Dec 11, 2009I have a unique situation in that I've developed a VB.NET application for AutoCAD. The way this works, you build your project into a dll and utilize AutoCAD API references when designing the project. From AutoCAD, a "Netload" command will load your dll into it's namespace to run. AutoCAD then essentially takes ownership of your application from here on out. The application is ran using a command defined in a method's attribute:
<CommandMethod("CommandNameForApp")>Public Sub MyCommand()
'Code Here
End Sub
Due to the heavy load of processing loops as it evaluates AutoCAD drawing data, processes this data, and generates many, many Excel reports, I've added a boolean property called Cancelled to my Progress class. When the user cancel's the process, this is seen by the process and further evaluation is ended and everything is cleaned up nicely. In order for this to work though, I have to implement Application.DoEvents. Without it, the Cancel feature will not work at all. With it, now instead of allowing the application to stay loaded, the Command method is fully closed.I have added a go-to point and simply verify that the application isn't closing because of a user-cancellation event. Here's what it looks like now:
<CommandMethod("WireShop")> Public Sub WireShopApplication()
'Initialize Configuration File Data
'Initializes ValidBlocks, MarginDistance, WindowDistance, and HelpFileName Properties
If ConfigurationFileInitialization() = False Then Exit Sub
[code].....
In my opinion, this seems a little hokey. However, I'm not that familiar with exactly what Application.DoEvents is doing in the background to understand how to "head it off at the pass".
CascadeWindows Win32 Function Throws An AccessViolationException On Windows 7?
Aug 31, 2010Private Declare Function CascadeWindowsNative Lib "user32" Alias "CascadeWindows" ( _
ByVal hwndParent As Long, _
ByVal wHow As Long, _
ByVal lpRect As Long, _
ByVal cKids As Long, _
ByVal lpkids As Long) As Integer
calling:CascadeWindowsNative(Nothing, &H4, 0, 0, 0)
Get System.AccessViolationException When Calling The PowerEnumerate Function Of Powrprof.dll?
Apr 1, 2011I am trying to find the time-outs the user has set for the PC similar in function to the command line:
powercfg /q SCHEME_CURRENT SUB_SLEEP but I want to do something a bit more elegant than firing off a command and parsing the values out of the captured output. I've managed to source a number of element examples from the net and cobble parts together into a program.
I've got a fair way but am now stuck on the call to powrprof.dll - PowerEnumerate function. I've checked it on Microsoft's site and my call seems to be okay yet it still fails with 'System.AccessViolationException was unhandled'
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Application.doevents() Causing Some Sort Of Overlap?
Nov 9, 2009I'm trying to automate the process of logging into twitterfeed.com, and filling in the information (the feed url and twitter username are pulled from textboxes). I had it mostly working the other day, even if it is a bit sloppy (the only way I could get one button to click is to send 50-some tabs). However, lately it seems to enter in a sort of loop. When I pause the program, Visual Studio indicates that it is the Application.DoEvents in the Private Sub "wait" that is still running even after it should be.
Public Class Form1
Private feed, username, temp As String
' Code stolen off of a website as an alternative to sleeping, or trying to do a timer + while combo like I had been doing
[Code].....