.net - Exception Handling: Is Finally Executed After Throw?
Oct 16, 2009Assume you have the following code:
Instead of doing:
Try
'
[code].....
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If Throw An Exception From Within A Catch, Does The Finally (from The Catch) Still Execute
Jun 2, 2009If I throw an exception from within a catch, does the finally (from the catch) still execute? i.e.
Try
..some code with an exception in it...
catch ex as Exception
throw new SpecialException("blah blah" & ex.Message, ex)
[code]....
Catch An Exception And Throw A New Exception Which Wraps The First Exception As An Inner Exception
May 8, 2009It is possible to catch an exception and throw a new exception which wraps the first exception as an inner exception: [URL] Also, if I call a function and it throws a certain error, but I catch it, will the calling code's catch handler execute? If so, and it is of a higher exception type, is this not wrapping the exception? eg I can throw exception ex of type IndexOutOfRange, log it but rethrow, catch a higher up exception and do something, or I can throw a new exception and wrap an inner exception like:
View 1 Replies.net - Try Catch Finally Blocks.. Do I Still Need Them When Handling Errors In The Global.asax
Jun 2, 2010I am handling errors via my global.asax in this method:
Dim CurrentException As Exception
CurrentException = Server.GetLastError()
Dim LogFilePath As String = Server.MapPath("~/Error/" & DateTime.Now.ToString("dd-MM-yy.HH.mm") & ".txt")
Dim sw As System.IO.StreamWriter = New System.IO.StreamWriter(LogFilePath)
[code]....
In my code I currently have no other error handling. Should I still insert try, catch, finally blocks?
IDE :: In Finally Block - Check If An Exception Occurred Or Not ?
Sep 18, 2011In Finally Block, How can we check if an exception occurred or Not.I am programming in VB.Net. Why i am asking is that in the Finally Block there could be some things you would like to do if an Exception has occured and some things you want to do if an exception has not occured. So, within finally block how do we know if an exception has occured
View 11 RepliesNull Reference Exception In Finally Block
Jul 2, 2009does any one know the reason of why I get Warning in the Finally block in vb.
[Code]...
Within The Finally Block, Check If An Exception Occurred Or Not ?
Sep 18, 2011I am Not using the "Catch Ex as Exception" for some of my application's architect details.So, if my code is something like
Try
'code here
Catch ex As ApplicationException '!!! i.e. ApplicationException
[code]....
Catch / Handle And Then Again Throw Exception?
Jun 26, 2009I 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()
[Code] .....
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.
Series Of Commands, Any Of Which May Throw An Exception?
Jun 17, 20101) How is ON ERROR GOTO -1 used? I don't understand the help text.
2) ON ERROR seems to be deprecated. What is the recommended Try...Catch replacement for ON ERROR RESUME NEXT. ie. where I have a series of commands, any of which may throw an exception, and I want to ignore all exceptions yet attempt every command?
ShowDialog Throw Thread Exception
Feb 18, 2011I have written a VB.NET 2.0 code and in my code i am calling class.Showdialog and for that i am getting thread exception. I have mentioned the call stack of the exception. Can any one help me out to resolve this issue. [code]
View 5 RepliesIDE :: Throw Unhandled Exception During Debugging (VB2008)
Apr 24, 2009while my first .net steps I want to understand and test the Method
Private Sub MyApplication_UnhandeledException in ApplicationEvents.vb.
But if I throw an exception the IDE stops and says "unhandled exception" and gives solution tips.
Is it possible to switch off those exception warnings and run through the unhandeled exception handling in ApplicationEvents.vb ?
Throw Exception When Certan Property Or Value Is Negtive?
Feb 9, 2012I'm not getting any errors, or anything I just forgot how to do error checking in the "set" portion of properties
I have 3 Classes, my frmMain,Sales and a Validator Class
Code for the Validator Class:
CODE:
Code for my Sales Class:
CODE:
I need to Throw an Excepton when the Sales price is Zero or negitive and when the trade in allowance is negtive I'm not quite sure how to do that in the Object Oriented Manner.
Throw An Existing Exception While Preserving Its Stack Trace In VB?
Nov 18, 2011If I have an existing exception object (I'm not in a catch block, I just happen to have been given an exception object), is there any way (re)throw it while preserving it's stack trace?
The context for asking is that I'm writing a RunWorkerCompleted handler. If an error happened while running the background task, then this will have shown up in the Error property of the RunWorkerCompletedEventArgs. To keep the code simple I want to use the same error handling code to trap this, or any error that happens later during the handler. That means I need code like this:
Private Sub OnDone(ByVal sender As Object, ByVal e As RunWorkerCompletedEventArgs)
[Code]...
I don't think that using an InnerException here (ie. saying something like Throw new Exception(ex)) will work because then I have the problem that my Catch block has no way of knowing whether the exception it's supposed to be handling is the outer one or an inner one. StackOverflow seems to have various similar questions, but I've not found anything that describes this particular situation.
VS 2005 - Throw An Exception When Print To The Printer Using The PrintDocument
Oct 29, 2009When I print to the printer, using the PrintDocument, I want it to be able to throw an exception if there is a problem. Currently, if I print to a printer that has a jam, is offline, or doesn't even exist, VB still thinks it printed fine. I never get an error. How can I have the printer report back to my program so that if I print to a printer that doesn't even exist, it wont let me do it? I just tried adding a LPT1 printer to my computer (and there is no local printer). I called it some random printer and installed some random driver. Then used my program to print to that printer and never got an error.
View 1 Replies[2005] Throw Exception - Used Methods From Namespace System.IO
Mar 12, 2009I want to throw error, if i used methods from this namespace System.IO
For example,
If i write File.Delete("TempPath") , i have to throw undefined Method..
Null Dates In Mysql Throw Exception When Loaded Into Datagridview?
Feb 15, 2012Having problems with null dates in a mysql table. Have eventually found out that I can store a 'null' date in mysql as "0000-00-00" and I can run the 'insert' command to add a record to the mysql table. When I check on mysql workbench I can see the row has been inserted correctly and the date shows as "0000-00-00".However...When I try to load the table into a datagridview, I get an error = mysql Conversion Exception was unhandled = "Unable to convert MySQL date/time value to System.DateTime".
View 4 RepliesAppdomain.unhandled Exception Event Is Not Always Executed
Jan 5, 2011I have a service application that randomly stops without any errors in my log or in the event application log. I believe that there could be an unhandled exception somewhere in the code so I set up the AppDomain.Unhandled event to catch any exceptions. While trying to induce unhandled exceptions I have found that this event is not always fired. I added the following code to my service's Shared Sub Main method (but I orginally had it in the OnStart method and was seeing mostly the same thing)
Dim currentDomain as AppDomain = AppDomain.CurrentDomain
Add Handler currentDomain.UnhandledException, Address of MyHandler
Reader.getDateTime(2) Throw Exception "Invalid Cast"?
May 30, 2011I have below program that throw exception. Do you know how to fix??
Dim conn As New SqlCeConnection
conn.ConnectionString = "Data Source=" & Dir & StockTakeFile & ";Persist Security Info=False"
conn.Open()
Dim cmd As New SqlCeCommand("select * from TableStockTake", conn)
Dim reader As SqlCeDataReader
reader = cmd.ExecuteReader()
[Code]...
Exception Handling Best Practices .Net?
Dec 8, 2009I have a general question regarding best practices for exception handling. I have a class library that uses structured error handling. The functions in the library generally perform some mathematical calculations and all return a boolean value indicating whether an exception occured or not (i.e. exception occured = true, no exception = false). The actual calculated result in the function is returned as a ByRef parameter.
Anyway the input variables for my calculations are all passed to the funtions as parameters. I perform some basic checks on these inputs (e.g check that an input is not negative etc) as part of the function code. The next stage is where im unsure of the best way to do things. Using the example i just mentioned, if an input parameter is negative, I can either throw an exception such as "ArgumentOutofRange", or i can simply show a messagebox with some info about what happened. Either way i do it the function will return true. At the moment i am throwing an exception, but on reading the "Best practices for exception handling" it is recommended you dont throw an exception for things that can be checked programatically because of "performance/overhead issues".
I'm a little confused by what they mean by this. What kind of overhead are they talking about? Slower program? More disk space required? More memory required? When my functions return true, the calling methods basically drop everything and stop calculations (exit sub), so im not sure that the overhead issues they are talking about are as important to me. It seems easier and neater to throw an exception and utilize some global error strings and pass some parameters rather than copy and paste messagebox.show() all the time, and modify the text to suit the situation. Another argument for me would be that both methods of exception handling utilize a messagebox, which stops code execution until the user does something. So i cant see the issue with the performance overhead.
Handling A File Exception In .NET?
Apr 6, 2012for the program I am creating I want the computer to check if the configuration file has been created or not. I wrote this function to do that but I don't how to handle a file exception. Here's my code currently but obviously it returns an error if the configuration file doesn't already exist. So how do I add a check for an exception?
Public Function CheckIfRunBefore()
Dim ConfDirectory As String
ConfDirectory = ""
Dim StreamReader As New IO.StreamReader("C:\VRAI\Conf.txt")
[code]....
Incorporate Some Exception Handling
Sep 29, 2009I am currently working on my Final Project and I need to incorporate some Exception Handling. I have created one in the following code but it isn't working. I don't have any "Errors" or "Warnings" but when I run the program it says the "BadNameException was unhandled." I thought I followed the steps correctly from my book, but I am stuck somewhere. [code]
View 6 RepliesProcedures And Exception Handling?
Aug 6, 2009I initially posted this in the wrong forum. I need help getting this to run properly. I'm trying to construct a fractions calculator. In order to complete it, I need to do it like this:Using Select Case statements, four Function procedures should be called based on the operation selected. Each Function procedure will calculate the correct operation and return the Decimal value to the calling procedure. The original procedure will print the result.
Now, the result should be calculated to the hundreths place and the input values should be validated by a Try-Catch Block.And of course, I've been having trouble with how to do this. I've attempted many times and this is what I have so far:
[Code]...
Recordset And Exception Handling
Feb 22, 2010I have been using VB6.0 to create database-driven Apps. With VB6.0, I could Dimi recordsets to read/write data from/into database tables. I could use the read data to validate textbox controls on the Windows Forms. But I when I upgraded VB6.0 Apps to VS 2008, I had problems with PowerPacks not found, Exceptional Errors etc.Most of all the problems I have experienced are:
- Overload Resolution failed because no accessible 'item' accepts this number of arguments.
- Error Code -2146825023
- Exception Snapshot - {"Item cannot be found in the collection corresponding to the requested name or ordinal."}
- Interop Errors[code]
Resume Next In Exception Handling?
Jan 25, 2011I have converted vb6 code to vb.net but in vb6 I used errorHandler in VB.NET we used "Tyr and catch" block
but In catch block resume next gives an error bcoz it is not valid for vb.net
[Code]...
VS 2005 With Exception Handling?
Jan 7, 2010i did this little bit of Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[Code]...
Check If A File Is In Use Without Exception Handling?
Apr 28, 2009Currently to check if a file is in use (before attempting to move or send it by FTP etc) we try and open it with exclusive right and trap the System.IO.IOException that would occur if anotehr process is reading or writing the file.
However - how can we do this without the bad paractice of using an exception handler for unexceptional process flow?
Detailed Exception Handling Resources?
Jul 27, 2010Good, detailed resources or books for best-practices on exception handling? I am looking to dive into a much deeper understanding of it, and am finding it hard. All the books I see over .NET, ASP.NET, etc. place little emphasis or detail on exception handling.
I am currently testing out a 3-tier ASP.NET application, with a presentation layer, business logic layer, and data layer, and want to know more about exactly when to throw errors, when to catch them, what layer to do them in, etc.
I don't want a simple google search on ".NET exception handling" and then having you post the first couple of links. I would like you to respond if you have quality, known resources that you have used or have found.
Exception Handling - Can't Catch COMException
Feb 24, 2012I use the following code to access a VSS item:
Dim sItem As String = "$/MyVssProject/InexistentFile.txt"
Dim oItem As SourceSafeTypeLib.VSSItem = Nothing
Try
[Code]....
The problem I face is when I try to get an instance to a file that doesn't exist in the VSSDB, thus leading to a COMException, which basically wouldn't be of a problem (I would expect). In fact the exception occurs, but instead of proceeding with the catch code, the debug cursor stays on the line "oItem = m_oSourceSafe.VSSItem(sItem)", showing a dialog with title "COMException crossed a native/managed boundary.
From here the execution doesn't proceed, until I change the content of sItem to an existing file.
Why does the exception not get caught, and how can I achieve it?
Environment: VS2010 with .Net 2.0 on WinXP SP3 x86
Exception Handling - QuoteUnauthorizedAccessException Was Unhanded
Oct 6, 2010Im using (virtually) the same code in two different projects, in the first, much older, program the code works well and had done for years. In the second the same code produces and Exception error.
QuoteUnauthorizedAccessException was unhanded.
Access to the path ˜C:/Jotto 1.gtc is denied.
Troubleshooting tips:
Make sure you have sufficient privileges to access this resource. If you are attempting to access a file, make sure it is not ReadOnly.
Actions:
View Detail...
Copy exception detail to the clipboard
The detail copied to clipboard says: -
CODE:
Which sadly means very little to me and I cant make head nor tail of what the Help, says... The only difference between the two codes is that in the first, working, project the file I wish to delete is named specifically whereas in the second, its named as a variable.
CODE:
The code runs ok up to the second of these lines, so the filepath has been verified. Have I perhaps missed something earlier in the code? some preconditioning perhaps ?
Exception Handling 3rd Party Softwar
Apr 27, 2009What 3rd party software is out there for exception handling for VB.net code?
View 4 Replies
