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?
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"
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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.
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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
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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.
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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.
View 2 RepliesI 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.
View 1 RepliesI 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?
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]
View 3 RepliesSay I have a button that creates more buttons with a random .Text property, and placed them on the form in different locations. And since these buttons are being created at runtime, I want to be able to have an event handler for all button controls on the form that makes the form's text the same as the sender's text.
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Notice the catch (Type) instead of catch (Type myVariable). Is this possible with VB.NET, or do you always have to declare a variable when you catch exception types, like so:
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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.
on the msdn pages describing classes etc, there are a lot of properties and methods mentioned from classes. But is there a kind of property of a class or method which gives te collection of expected errors ?i ask this because in the try catch statement you can specify the exceptions and errors you want to catch, but
View 4 RepliesWe have just converted a large VB6 desktop app to VB.NET 2008. First via the VB 2005 (opened the project), then days of fixing errors, etc. Then opened the VB 2005 in VB 2008 so now it is a 2008 solution. There are about 30 forms with code behind and about 40 other modules.
Message InvalidOperationException was unhandled.
... The type initializer for .... threw an error.
on
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Hmmmm having discovered that using the mciAPI doesn't utilise 5.1 sound, but using a virtual WMP does - I started a new approach to my multimedia project using some code from the net. BUT I keep getting exceptions (particularly with type casting). In the subrountine 'Player_PlayStateChange'.
The listing (see below) is now well commented by me. Can anybody please help concerning the damn annoying exceptions and stop me pulling my hair out.
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I have a large project where we have 2-3 dll projects that are converted from VB6 to VB.NET. We have fixed all the issues that caused compilation errors, and most of obvious issues in running, so now we have basically a program up and running. The exe is created from scratch in VB.NET, using a lot of functionality from the converted dll's (including GUI forms). What I wonder is when I run the program in debug mode, I get a bunch of warnings in the "Immediate Window" saying:
A first chance exception of type 'System.Exception' occurred in Microsoft.VisualBasic.dll
...and some of other type (but most of them in Microsoft.VisualBasic.dll).I was wondering if this is common in projects converted from VB6, or if it is caused by bad design in our code...
I'm trying to catch a user defined permission exception - i.e. a user does something their level of system access won't allow, permission exception is thrown. My problem is, the exception is caught and then rethrown as a genertic System.Exception.Is there any way I can deduce the original exception type, without resorting to string comparisons, like if ex.ToString.Contains("Permission denied"
View 2 RepliesWhen catching an exception in .net, you can have as many type-specific exception blocks as needed. But I usually try to have at least one "general" exception catch block. But is there a way to get the type of the "real" exception thrown that is caught by the generic exception handler, perhaps using reflection?For example, if I have
Catch ex As System.ServiceModel.FaultException(Of InvalidUser)
ProcessModuleLoadException(Me, ex)
Catch ex As System.ServiceModel.FaultException(Of SQLExceptions)
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I just tried to run a project of mine that has a wpf control in it and i get the error:Exception of type 'System.ExecutionEngineException' was thrown.The error automatically closes after about 3 seconds When I create a new WPF project visual studio closes down - no error messages, also just closes with no errors if I create a form application and add a WPF control to it. Also compiled applications just bring up the "xxx has stoped working" error - even apps that are not mine such as Microsoft Pivot that use WPF?
View 4 RepliesI have an assembly containing a number of classes. This is a class library type assembly, not a windows forms application. It's also single threaded.Is there a way to catch all un-handled exceptions so that I can log them?
View 2 RepliesI was working on a project in my VB.NET Express and suddenly my code that was working fine and starting up as normal gave me this error:
{An error occurred creating the form. See Exception.InnerException for details. The error is: Corrupt .resources file. Got an unexpected EndOfStreamException while trying to read the ResourceReader header.}
When I'm trying to run my application, it doesn't open my main form.
System.ExecutionEngineException was unhandled Message: An unhandled exception of type 'System.ExecutionEngineException' occurred in Unknown Module.There are no further details and the stack trace window is blank I was just wondering how it would be best to work out where this error message is happening - i really don't want to put a million debug.prints in there to work out what functions were last called etc.
View 2 RepliesI ran into an interesting dilemna today. I have a function that handles information and checks for duplicate values, then returns the next number that is not a duplicate. So, I have something like this:
Public Function GetNextNonDuplicateNumber(NumberToCheck as Long) as Long
//the non-duplicate the function will return
Dim NonDuplicate as Long
'duplicate
If CheckForDuplicate(NumberToCheck) = True Then
Throw New DuplicateException()
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As you can see, I want to handle the exception specifically, but I also want to throw it when I'm done because I want to alert other code outside the function. The problem is that simply throwing it exits out of the function with a null value.
i am using data grid view.if i loaded this data grid view with about 15 and above rows and traverse in data grid view by pressing down arrow key then an unhandeled exception throws.The unhandled exception is as below value of '176' is not valid for 'value' .'value' should be between 'minimum' and 'maximum' parameter name value..
View 2 RepliesI 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
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I have one user that is having a problem with my application, the error report shows an event type of clr203r and an index out of range exception. From what I've read this seems to have "something" to do with arrays or lists. (What that something is, so far, is beyond me or anything I've researched). I do have one array in my program -- myarray(13) as byte and I do have the syntax right as far as noting 20 elements in it. in my other bits of code.
I'm reading those bytes in the serial port, deciphering them and performing some actions. (to be vague). But just with what I've said, can anyone point me to a possible problem? Is the index out of range exception ALWAYS concerned with just arrays or lists? Or could it be something else?
What do you think is the best way of handling a Timeout Expired exception?
View 4 RepliesI want to force a calling method to implement exception handling.
Java forces a calling method to implement exception handling where it calls another method that thorws an exception.
Does VB.Net have the same mechanism?
I am trying to get a list of files using this line of Dim files() As String = IO.Directory.GetFiles("D:", "*.*", SearchOption.AllDirectories)But it errors out on folders that are inaccessible, like the RecycleBin folder & the program stops. So how do I get a list of files in all folders, while skipping the inaccessible one
View 1 RepliesI have searched other forums, google, etc. and have not find a solution. I am creating a VB.NET application using Visual Studio 2010. My application runs fine inside the IDE. Outside of the IDE, it crashes immediately with an OOM exception. I have compiled the program in both VS 2010 and VS2008. The outcome is always the same. I increased my Desktop heap to 12288 meg from 3072 meg thinking that was the issue, but the outcome is the case. Although the increase does improve my response in the IDE. The error is also being reported as related to mscorlib.dll; and my version is for 2.0 framework is 2.0.50727 and for 4.0 framework is 4.0.30319. I am running Windows XP/SP3.
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