Try Catch Finally Doesn't Work?
Mar 23, 2010I've a class with a timer inside
Private tt As New System.Timers.Timer()
This timer is enabled in the New() of the class
Try
[code].....
ADVERTISEMENT
C# - Use Case For Try-catch-finally With Both Catch And Finally
Feb 17, 2010I understand how try-catch works and how try-finally works, but I find myself using those (usually) in two completely different scenarios:
try-finally (or using in C# and VB) is mostly used around some medium-sized code block that uses some resource that needs to be disposed properly.
try-catch is mostly used either
around a single statement that can fail in a very specific way or (as a catch-all) at a very high level of the application, usually directly below some user interface action.
In my experience, cases where a try-catch-finally would be appropriate, i.e., where the block in which I want to catch some particular exception is exactly the same block in which I use some disposable resource, are extremely rare. Yet, the language designers of C#, VB and Java seem to consider this to be a highly common scenario; the VB designers even think about adding catch to using.
Or am I just overly pedantic with my restrictive use of try-catch?
EDIT: To clarify: My code usually looks like this (functions unrolled for clarity):
Try
do something
Aquire Resource (e.g. get DB connection)
Try
[Code]....
which just seems to make much more sense than putting any of the two catches on the same level as finally just to avoid indentation.
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]....
Get This Error When Trying To Populate A DataGridView / A Try...Catch Doesn't Work
Sep 2, 2009I get this error when trying to populate a DataGridView.The last sentence of the error text says to handle the DataError event but I'm not sure how to do that. A Try...Catch doesn't work.
View 17 Replies[2005] When Try - Catch - End Try Doesn't Work - Crashes Or Throws Up An Error
Mar 15, 2009I've used this in a couple of places and it simply doesn't work. Despit the try event, VB.Net still crashes or throws up an error.
View 14 RepliesWhy Use Finally In Try/Catch
Nov 25, 2009OK, I'd like to know the difference between the following two blocks of code:
Block A
Try
Something
[code].....
C# :: Why Can't Write Just A Try With No Catch Or Finally
Dec 27, 2010Sometimes I do this and I've seen others doing it too:
VB:
Try
DontWannaCatchIt()
[code].....
Catch Exceptions In Finally Block?
Oct 13, 2010Is there some special way to catch exceptions in finally block ?
View 2 RepliesReturn Inside Try/catch/Finally?
Sep 15, 2009I have a (begginner) question on VB.NET. Is this good code (I mean, is it "bullet proof")?. It seems to work, but I understand the Return is executed AFTER the Finally. So how does it call a method on an allready disposed of object?
[Code]...
VS 2008 How To Use Try Catch Finally Statement
Jun 15, 2009i want to know how to use try catch finally statement.i want to catch this error Violation of PRIMARY KEY constraint 'XPKemployee'. Cannot insert duplicate key in object 'dbo.employee'.
View 4 RepliesVS 2008 How To Use Try..Catch...Finally Statement
Mar 4, 2011i have this problem about the try,catch,finally statement... i don't know how to use it..i have my converter program here and this should be type by a letter 'cause if you do it will go lag or hang...i try VERIFY button to make sure if it's a letter or number but my teacher said it's not counted...
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If ComboBox1.Text = "Pounds To Kilo" Then
[code]....
Which Is Faster - A Using Block Or Try / Catch / Finally
Sep 2, 2010This is a followup question to this Should I stick with the Try/Catch/Finally construct, or go with the Using construct? Sample Code for Try/Catch/Finally:
[Code]...
.net - Replicate Try/catch/finally Using On Error Goto
Jun 14, 2012Suppose in VB.NET you have:
Try
Debug.Print("Trying...")
Catch ex as Exception
throw new Exception("Exception", ex)
Finally
Debug.Print("Finally...")
End Try
How would you write this using the "On Error Goto" construct? (please no questions asking why I would want to do this, just curious if it can be done).
Trap Any Exceptions With Try Catch Finally If The Reader?
Apr 8, 2011I have a SqlDataReader and I want to trap any exceptions with Try Catch Finally if the reader =cmd.ExecuteReader() statement fails. If this statement throws an exception do I need to close the reader? If so, where. Wherever I place the reader.close() statement I get an error that the reader has not been assigned a value yet.
View 2 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?
Is Try / Catch / Finally Required With Using Statement In Order To Handle Exceptions
Jan 31, 2012I 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 RepliesTooltip On Windows 7 Doesn't Work VB2010 - Thecolor Doesn't Change ?
Jun 12, 2011I am trying to change the background color of a tooltip
I am using tooltip.backgroundcolor = color.colr
No errors but thecolor doesn't change
PerformClick() Doesn't Work - How To Make It Work
Feb 2, 2011I have an application that requires data be entered, and after entering, a button is clicked to process that data. Clicking the button works just as it should--the data is processed properly. In constructing a test module, I provide a set of data values, followed by:
btnWhatever.PerformClick()
Nothing happens. I have used this syntax for years, and it has always worked flawlessly. I have triple checked everything else and isolated the problem to the failure of the PerformClick(). The PerformClick() is in a test subroutine that does nothing but fill textboxes and labels with default data, then calls the PerformClick() on the button to begin processing. Again, the button works fine, the data is entered as it should be, but the PerformClick() does not fire the click event.
Get The Try/catch To Work With Text Boxes And Input From The User?
Feb 4, 2010I'm familiar with Visual C# and the try/catch for that but I cannot seem to figure out how to do the same thing in VB. Basically I can't figure out how to get the try/catch to work with text boxes and input from the user and whatnot.I've tried setting the textbox.text property = "" but that has no use, I've been trying to find something on Google about it but I cannot seem to find a single thing about textbox try/catch statements. Is it possible to do it with text boxes?
View 5 Replies.net - Datagridview Doesn't Work
Sep 13, 2010Possible Duplicate: Datagridview doesnt work! I have written code to show records in a datagridview but it shows nothing. I have tried to debug & when it step into GetData function following codes
Catch ex As Exception
returnData = Nothing
If connection.State = ConnectionState.Open Then
connection.Close()
End If
become gray & it shows error sign. When I take my mouse pointer on it it shows message. It says "Cannot open database SUIMT requested by the login. The login failed. Login failed for user 'MY-PCJames'".
Imports System.Data.SqlClient
Public Class Form34
Private Const ConnectionString As String = "Server=.SQLEXPRESS;" & _
"Database=SUIMT;Trusted_Connection=True"
[code]....
.net - VB 2 Streamreaders, One Doesn't Work?
Oct 11, 2011So I have 2 data files, single dimension, that I'm trying to populate two rtb. If I comment one streamreader out the other will print. This also works in the vise versa situation. Does anybody see where I'm going wrong with this? They won't run together.
Dim Alpha As New System.IO.StreamReader("alpha.dat")
Dim Beta As New System.IO.StreamReader("beta.dat")
Dim strLine As String
[code].....
.NET: Why Doesn't This Nullable Work
Dec 15, 2010dim str as nullable(of string) is this syntax incorrect?
View 1 RepliesAxAcroPDF Doesn't Work When Using MDI?
Nov 26, 2010i'm working on a MDI application and need to view a ".PDF" files in a MDI child form, but when using the AxAcroPDF control it doesent work, note that it works fine when viewing the form separately from the MDI application.
View 14 RepliesBackgroundworker Doesn't Work?
Aug 21, 2011this is my code:
Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
For i = 0 To 1000
[code]....
Dll Doesn't Work On Any Other Computer
Mar 15, 2012Has anyone succeeded in creating a class library solution/project in VB.net VS2010 4.0 Net Framework for COM to run on WindowsXP Excel 2003. I created a dll which changed specific data in an excel worksheet. The dll worked just fine on the development computer but wont work on any other. I downloaded .NET 4 framework onto the target PCs and used RegAsm.exe to register both the .dll and .tlb files in the registry. That worked OK and the dll is visible as a reference in excel and can be ticked. The error message I get is RunTime Error -2147024894(80070002): Automation Error The System cannot find the file specified.
I also tried creating a Setup and Deploy project in the original development solution but this created just a vbproj setup file which the target PC cannot read (no VS installed), I hoped the project would create an EXE file I could use. Does anyone know any links that describe how to do this type of stuff as most links I have tried are either for Windows Forms projects are are way above my knowledge. Maybe someone out there has already succeeded with this sort of activity?
Express DLL Doesn't Work On Other PCs?
May 24, 2012I have Visual Studio 2010 Express Edition. I'm using it to evaluate functionality before purchasing the real thing, but I'm having trouble. I want to build a DLL that can be used on PCs other than my development PC, that I can call from VBScript.
I follow the hundreds of examples out on the intranet and things still don't work.I have built a simple HelloWorld DLL with a function that returns "Hello World".I've been through all the stuff about making the assembly COM visible, and the threads about Register for COM Interop checkbox missing. One person suggested editing the .vbproj file and adding a tag to turn on Regiser for COM Interop (which was not needed because it was already there).
Anyway, if I build my project and run my VBScript:
Set testdll = CreateObject("HelloWorld.Class1")
wscript.echo testdll.HelloWorld()
Everything works great. But....if I copy the DLL to another PC and register it with RegAsm, the VBScript fails with a "File not found" error on the CreateObject line of the VBScript.
In fact, if I unregister the DLL on my development PC and then register it with RegAsm, the VBScript now fails on my development PC. RegAsm said everything was okay and if I look in the registery using RegEdit, things look good, but it still doesn't work. The only way to get it to work again is to rebuild the DLL (which in turn, registers the DLL).
I'd like to be able to build a DLL which I can be registered and used on other PCs (without requiring those PCs to have Visual Studio 2010 EE and without requiring them to have the source and build the DLL).
If Statement Doesn't Work Right
Oct 13, 2009Dim
a As Date? = Nothing
Dim b As Date? = If(a Is Nothing, Nothing, GetValue(a))
I thought b would be Nothing, but it is not...is it a bug?
IsDBNull Doesn't Work
Dec 3, 2009I am getting a datarow from my dataset and some columns can be NULL.So I am trying to check for this using the IsDBNull function, but it just won't work. I have tried almost every possible combination. Can someone please explain to me how to use this properly?ser is a datarow and GUID is a column with data type: unique indentifier (so a Sytem.Guid)
user.GUID.Equals(DBNull.Value) Then .GUID = System.Guid.NewGuid
I tried using above, IsDBNull(GUID), guid = dbnull.value, guid is dbnull.value etc etc I am just getting this error: The specified Cast is not valid.
[code].....
OOP-inherition Doesn't Work?
May 13, 2009why this code doesn't work?
[Code]...
Picture Box Doesn't Work
Sep 25, 2009i made a picture box and the fowling event when my program runs:
[Code]...