In this VB.NET code:
Dim o as SomeClass
Try
o = new SomeClass
'call some method on o here
Catch(...)
Why is there a need to set o to Nothing? What if i don't set it to Nothing in the Finally block? What i think is that it is OK if you don't set it to Nothing because the object will be marked for GC.
I often use the Try block to catch exeptions, and I have read in the help pages to do with the Finally statement. But, from what I understand it has no use whatsoever. Why would I use Finally instead of just ending the Try block. For example, from what I know
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Is there some special way to catch exceptions in finally block ?
View 2 RepliesThis 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:
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Well, I've read (and learned) that the finally block doesn't always execute its code (even apart from pulling the plug).FYI For more information, see try catch finally question
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In 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 Repliesdoes any one know the reason of why I get Warning in the Finally block in vb.
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I 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]....
I have the following VB6 code:
Public Function GetSetting(ByVal key As String) As String
'xml document object
Dim xd As New DOMDocument
'load the xml file
xd.Load (strSourceFile)
[Code] .....
I have read several places that indicate this should work, but it doesn't. The selectSingleNode blows up with "Error: Object variable or With Block variable not set."
I 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.
Is there a more elegant way to structure the following code, which takes a comma delimited string containing certain values in specific positions and assigns the values to the properties of an object?[code]...
View 5 Repliesi have this error in the line of with xl.active......Object variable or With block variable not set.
Dim xl As Object
xl = CreateObject("Excel.Application")
With xl.ActiveSheet.QueryTables.Add(Connection:= _
"TEXT;C:Documents and SettingsUserDesktop429MEDICA2.TXT", _ Destination:=xl.Range("$A$1"))
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Now I have the need to get a current value from a bindingsource in a property of a user control.In a previous thread I had tracked down the "Object variable or With block variable not set" to the return in the Get block of a property. At the time I was only using the Set so I just commented out the offending code until I needed it.
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The error does not occur during a system compile, only upon saving the container object of the user control. As I said the Set works correctly, only the Get causes the error.I would like to know what I am missing/misunderstanding and am open to other suggestions of handling retrieving the current value of a bindingsource in a user control.
i had a class called Tag with a structure like:
public class Tag
private _members
public properties
public shared database_methods
end class
this class was tailored for mysql database. i'm currently adding access 2007 support so i split tag into tag and tagdata with structures like:
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I'm having trouble tracking down what is wrong and causing the above error. This only occurs when saving the design view in VS 2012. The code builds and runs fine.Full error text:Code generation for property 'CompanyValue' failed. Error was: 'Property accessor 'CompanyValue' on object 'ContactViewUC1' threw the following exception: 'Object variable or With block variable not set."
CompanyValue definition in ContactViewUC:
Public Property CompanyValue
Get
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Been getting this error with my program. Using framework 2.0
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I am trying to use this block of code to save attachemnts from Outlook into a folder on my harddrive.
VB
Imports Microsoft.Office.Interop
''' <summary>
[code].....
I'm writing in ASP.NET 4 / VB.NET. I am querying an MSSQL database and sometimes have records come back with no results...so I enclosed the call I was making upon the results in an If..Else clause to set a default value if the database comes back with no results...but now I am getting this "Object variable or With block variable not set error". Here is the relevant code:
Dim clcfirst
Dim rhcfirst
Dim clcdate As Date
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I am populating combo box from database. In debug i can see that the combo box has been populated . here is the code
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OK, I'd like to know the difference between the following two blocks of code:
Block A
Try
Something
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Sometimes I do this and I've seen others doing it too:
VB:
Try
DontWannaCatchIt()
[code].....
I 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?
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I'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
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i 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 Repliesi 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
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Assume you have the following code:
Instead of doing:
Try
'
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Suppose 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).
I 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 RepliesI am trying to figure out why all of the sudden i get an error when trying to run my program. [code]The error i get is highlighted on the frmPM:..An error occurred creating the form. See Exception.InnerException for details.The error is: Object variable or With block variable not set.I've made sure there was a End Class at the end of all that but that doesn't seem to be the problem.What else could cause this as it worked just fine for one run then not on down the road?
View 1 RepliesI need your help to validate what is causing this error.This is the Stack Trace:
[NullReferenceException: Object variable or With block variable not set.]
Microsoft.VisualBasic.CompilerServices.Container..ctor(Object Instance) +498372
Microsoft.VisualBasic.CompilerServices.NewLateBinding.LateCall(Object Instance, Type Type, String MemberName, Object[] Arguments, String[] ArgumentNames, Type[] TypeArguments, Boolean[] CopyBack, Boolean IgnoreReturn) +112
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As you can see the error is returned on line 292 Uno_a_Uno function. I've searched but I can not resolve it is causing.