Random Exceptions: System.IO.IOException: The Handle Is Invalid
Dec 27, 2011
I have a relatively simple VB.NET app. It targets framework 2.0 from Visual Studio 2010. The app works fine most of the time, except that the users sometimes receive the
following exceptions. The error is completely random and somewhat rare. I haven't been able to trap it while in a development environment. It also doesn't appear to be
pointing at my code. My app continues to run if the users ignore the error. How would I trap and handle this error?
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May 3, 2011
Brief of my project: Taking attendance using RFID reader and RFID passive tag. Main tasks:
1) Scan a Tag and Tag ID is transmitted to GUI.
2) Tag ID is matched with Student ID in database.
3) Successfully matched Student ID is displayed on GUI and LCD.
When i had experienced this problem, student ID was only display on UI but not LCD. After that, my system hang. This happened only when the data of tag scanned is taken from text file through OpenFileDialog. Manually add of data via UI just work fine.
[Code]...
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Apr 1, 2009
I am building a chat client/server. And I can connect and chat just fine, but when a user disconnects, the server does not recognize this and acts weird, often spamming the last message that was sent by the user..Also, it's like the client does not disconnect from the server even when I close the client app. Once I exit the program, VB acts like it is still debugging. Once the server is shut down however, I get this error:
IOException was unhandled:Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.
serverStream.Read(inStream, 0, buffSize)I don't know how to make my client and server accept the fact that a client has disconnected...
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Apr 21, 2009
What types of exceptions should be thrown for invalid or unexpected parameters in .NET? When would I choose one instead of another?
Follow-up:
Which exception would you use if you have a function expecting an integer corresponding to a month and you passed in '42'? Would this fall into the "out of range" category even though it's not a collection?
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Apr 1, 2009
I have a SqlDataSource that is supplying data to my GridView. Thats all i am using on my form, thus i have NO code behind at all. But somewhere i need a TRY CATCH block just in case my connection get's lost. What code must i place where?
If i get a error i want my lblMessage Text to be "No connection".
Edit
My GridView in my Machine.aspx
<asp:GridView ID="GridView1" runat="server" AllowPaging="True" AutoGenerateColumns="False"
Height="209px" PageSize="7" Width="331px" AllowSorting="True"
[Code].....
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Mar 5, 2010
Several of my overriden Equals methods have started throwing Invalid Cast Exceptions -
Unable to cast object of type 'System.DBNull' to type Common.ResolveUser'.
This occurs when binding List (of T) (where T is of type ResolveUser in this case) to a combo.
Equals Method:
Public Overrides Function Equals(ByVal obj As Object) As Boolean
Dim i As ResolveUser = CType(obj, ResolveUser)
If i.UniqueResolveID = UniqueResolveID Then Return True
[Code]......
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Oct 12, 2011
I am developing an application that reads from a network shared folder on a separate Windows Server. When the application attempts to read, I am receiving the error message "System.IO.IOException: The Device Is Not Ready". I have tried running the application as an Administrator, however I still receive the same error.The files in question do not appear to be in use by any other application.
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Apr 2, 2009
I was reading a couple of articles a while back which I think described a behaviour where you can, in a .net application (specifically VB.net), allow an exception to occur, and then handle it in some kind of application-level exception handler, as opposed to within a Try/Catch block. My google-fu is weak at the moment, so I'm not having much luck guessing what this feature is called in order to find information about it.
[Code]...
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Aug 20, 2011
I am working on a .Net Remoting project. If there is any exception in remote object, I would like to send this exception in detail to the client. I am using the following code to accomplish that-
'This is on a shared .dll
Public Interface ICreateNewMouza
[code].....
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Jan 22, 2009
An application raises the UnhandledException event when it encounters an unhandled exception.
For instance, you can use this event to ask user send you a report by email.
[code...]
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Jan 15, 2012
In the following Sub I'm sending an Attachment when the email has been sent I would like to delete the attachment but I get an system.IO.IOException Error. the file I'm trying to delete is being used by another process. How can I detect if the process has finished.
CODE:
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Aug 26, 2009
Determining the max filename & path size of the OS.zip I whipped up a quick app to test the max filename & path length for a chosen folder. It works gr8 except when I choose the root of the C-drive. When I do, I get this error:
[Code]...
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Apr 17, 2012
I am receiving "A device attached to the system is not functioning" IOException in_serialPort.Open() in a Windows 7 PC (64 bits). The vb.net application is working ok in 32 bits and is compiled x86. In the device manager, the driver appears ok under Ports (COM & LPT) -it's a USB, CDC or virtual comm port.This exception occurs mostly all the time, but ocasionaly, few times, _serialPort.Open() has worked and the communication between the application and the hardware has been stablished. If the Pc is restarted and connected to the same port where the driver
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Dec 28, 2009
Is it possible to handle exceptions on the AppDomain.CurrentDomain.UnhandledException callback? I want to do the following:Show my own "an exception hasoccured" dialog, with a "Send Report"button After the user dismissed thebox, I want to close my app, but I donot want to Windows default crash dialog "Theapplication needs to close" box toshow up.
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Feb 26, 2012
I created a custom collection class with some methods: each of these has some parameters and throws an exception if a parameter is not valid.For example, the Add and Remove methods throw an NullReferenceException if one of their parameters is null.[code]...The Replace method replaces an item in the collection with another specified object: to reach the goal, it first calls the Remove method and after the Add method. Obviously the Replace method could throw exceptions if at least one of the specified parameters is null, because Remove and Add methods could throw exceptions.Is this the right way to go? Or should I also check the parameters in the Replace method as in the following code? [code]...In fact, in this second case, each check would be executed twice: first in the Replace method and after in the Remove and Addmethods, which are called by Replace, and in other cases the checks may be rather expensive.
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Apr 11, 2012
Is there a way I can catch and handle two different exceptions within the same exception type? For example:
Try
' My code
Catch ex As System.Net.WebException
End Try
I have 2 different exceptions that are System.Net.WebException. I want to handle them different ways. Problem is the catch block above catches them both. Is there a way I can determine if which of the two it is and handle them differently?
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Apr 11, 2011
I get the following error message when i try to copy a directory using folder dialogue to get the path, into a predestined path. The code is as follows:
[Code]...
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Jan 3, 2012
I'm writing a short app that will send an email notification, rename files and move them to a history folder after a DTS package runs and creates the files. It's a simple setup, the files will be in a folder. I'm attempting to rename them, then move them. For some reason, I keep getting System.IO.IOExceptions when I try to rename the files. Here's my code:
[Code]...
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Jan 31, 2012
I wonder how to use statement handles exceptions?Do I need to wrap the using statements with a Try/Cath/Finally clause in order to be sure that the SqlConnection object is closed and disposed even if the containing code throws an exception? [code]
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Nov 23, 2009
I am using VB.Net code to print barcode label in Zebra TLP 2844 printer. And the printer is connected to system by USB port. When i execute the code i get an error "Invalid Parameter : Name handle" in the line outFile = New FileStream(_SafeFileHandle, FileAccess.Write) . As this is a USB port So i shared the printer and used the UNC path. But still i get the error. Below is the complete code
[Code]....
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Dec 6, 2008
I'm currently developing a little hobby project to display health information in a game on my G15 keyboard through VB.NET. When I use ReadProcessMemory via an API call, it keeps returning zero. The MSDN documentation referred me to use the Marshal.GetLastWin32Error() call to find out what is wrong and it returns 1400: INVALID WINDOW HANDLE.
I am now confused about whether the first argument of the function wants a window handle or a process id. Regardless, I have tried both with FindWindow and hardcoding the process id while the application is running (getting it from task manager). I have tried three different games, Urban Terror, Grand Theft Auto: SA and 3D pinball for windows, getting the memory addresses from an application called Cheat Engine; they all seem to fail. [Code]
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Feb 22, 2010
Subsonic 2.2 is throwing the error
subsonic Invalid cast from System.Int32 to System.Byte[]
When I do the following
If template.Content Is Nothing Then
MsgBox("Blank Document")
Else
MsgBox("Document Present")
End If
"template" is a SubSonic object of which it's "content" field is of type Byte()
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Mar 10, 2011
how do I handle the errors that may appear from the user of my program. For example, I have an triangle area program in wich I ask the user of the program to insert the length of the base and height of the triangle in a textbox. But what if he inserts a letter or something else, like a sign....my program will crash...
I know that one method would be to use On Error GoTo but I don't know how. If maybe you can direct me to some link or you could explain how do I handle errors, I would be grateful. Maybe you can even show me other ways to avoid errors from the user input.
This is my small program so far:
Private Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs)
Handles Button1.Click
Dim , Height, ARIA As Integer
[Code]....
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Jul 18, 2010
In my VB.net Winforms application I'm using the ITaskbarList3::SetOverlayIcon interface to set status overlays on the application's taskbar button (under Windows 7). This all seems to work fine for me, with the icons being shown and removed correctly.From the form load event, one of my functions makes the callSetOverlayIcon(parentForm.Handle, IntPtr.Zero, String.Empty)(where parentForm is the form which the load event has fired for) which very occasionally (on other people's machines) throws the following exception:
System.Runtime.InteropServices.COMException (0x8007057A): Invalid cursor handle. (Exception from HRESULT: 0x8007057A)
at MyNamespace.TaskbarNotify.ITaskbarList3.SetOverlayIcon(IntPtr hwnd, IntPtr hIcon,
[code].....
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Nov 2, 2011
Why does SetOverlayIcon throw an 'Invalid cursor handle' COMException occasionally
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Aug 6, 2002
An unhandled exception of type 'System.IO.IOException' occurred in mscorlib.dll Additional information: The process cannot access the file "c:Fax524b2cfa00.tif" because it is being used by another process.
[Code]....
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Oct 7, 2009
i am making an application that grabs an image from a folder, sets it to a picture box, then has the option to delete the folder... when i click the delete folder button i get the error:
[Code]...
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Jan 16, 2010
Is the only way to create custom exceptions to inherit from System.Exception?
I wish to create a class that can be thrown as an exception but i do not wish to inherit from System.Exception because i have a base [Object] class in my library which all my classes should inherit from and i wish my custom exception class could also inherit from it.
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Jul 9, 2010
I Have just been watching a video on throwing Exceptions. Are you supposed to throw System.Exceptions from within your custom classes. to the calling code, Which other way can they communicate. I have read in several places it is bad practice to throw SystemExeptions.
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Sep 30, 2011
I am writing a custom application for IMAIl express 11.5 using IMAIl Server API for .Net
I am using the following code:
Dim DomData As New DomainData()
DomData.Aliases = "TestALias"
[code].....
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