Strange behaviour with if statement

[tborn]

Hi there,
Not sure if any one has experienced this before and can tell me what's
wrong with this statement:
if verified = false then dataObjects.Has Error = true
This is all on one line and verified is defined as a boolean variable.
Irrespective if verified is set to true or false in ALWAYS executes
dataObjects.Has Error = true.
Following code works as expected and dataObjects.Has Error = true
executes only if verified is set to false.
if verified = false then
dataObjects.Has Error = true
end if
To top it all of, I use the construct

if [expression] then [do something]
at other places in the program and it works fine.
Any ideas?
Thomas Born

[Tom Shelton]

On 8 Sep 2004 20:11:58 -0700, tb***@hlra.com. au wrote:

Hi there,
Not sure if any one has experienced this before and can tell me what's
wrong with this statement:
if verified = false then dataObjects.Has Error = true
This is all on one line and verified is defined as a boolean variable.
Irrespective if verified is set to true or false in ALWAYS executes
dataObjects.Has Error = true.
Following code works as expected and dataObjects.Has Error = true
executes only if verified is set to false.
if verified = false then
dataObjects.Has Error = true
end if
To top it all of, I use the construct

if [expression] then [do something]
at other places in the program and it works fine.
Any ideas?
Thomas Born

Are you sure that it is actually executing? It seems there was a problem
with the debuger and single line if statements... Basically, it gets out
of step and it looks like it is executing the statement, but in reallity
it's not. Check the values, before and after you step to confirm.

--
Tom Shelton [MVP]

[Greg Burns]

Yeah, I've see that exact weirdness in the debugger myself. (It doesn't
actaully execute it).

I almost pulled my hair out trying to debug this line of code:

Try
...
Finally
If Not cn Is Nothing AndAlso cn.State = ConnectionState .Open Then
cn.Close()
End Try

:^)

Greg

"Tom Shelton" <to*@YOUKNOWTHE DRILLmtogden.co m> wrote in message
news:14******** *************** ******@40tude.n et...

On 8 Sep 2004 20:11:58 -0700, tb***@hlra.com. au wrote:

Hi there,
Not sure if any one has experienced this before and can tell me what's
wrong with this statement:
if verified = false then dataObjects.Has Error = true
This is all on one line and verified is defined as a boolean variable.
Irrespective if verified is set to true or false in ALWAYS executes
dataObjects.Has Error = true.
Following code works as expected and dataObjects.Has Error = true
executes only if verified is set to false.
if verified = false then
dataObjects.Has Error = true
end if
To top it all of, I use the construct

if [expression] then [do something]
at other places in the program and it works fine.
Any ideas?
Thomas Born

Are you sure that it is actually executing? It seems there was a problem
with the debuger and single line if statements... Basically, it gets out
of step and it looks like it is executing the statement, but in reallity
it's not. Check the values, before and after you step to confirm.

--
Tom Shelton [MVP]

[Chris Dunaway]

On 8 Sep 2004 20:11:58 -0700, tb***@hlra.com. au wrote:

if verified = false then dataObjects.Has Error = true

An alternate way to code this line would be to avoid the if altogether:

dataObjects.Has Error = (Not verified)

--
Chris

dunawayc[AT]sbcglobal_lunch meat_[DOT]net

To send me an E-mail, remove the "[", "]", underscores ,lunchmeat, and
replace certain words in my E-Mail address.

[Cor Ligthert]

Hi guys,

I made this test and in my opinion it goes as it should go, where did I go
wrong?

Cor
\\\
public class doedoe
Public shared sub Main
Dim dataobjects As New mycl
Dim verified As Boolean = True
If verified = False Then dataobjects.Has Error = True
If Not dataobjects Is Nothing AndAlso dataobjects.Has Error = False
Then
MessageBox.Show ("should be right")
End If
End Sub
End Class
Public Class mycl
Private mHasError As Boolean
Public Property HasError() As Boolean
Get
Return mHasError
End Get
Set(ByVal Value As Boolean)
mHasError = Value
End Set
End Property
///

[Greg Burns]

Your example didn't do it for me either, but mine does:

(this code makes no sense, just an example)

Imports System.Data.Sql Client

Public Class doedoe
Public Shared Sub Main()

Dim cn As New
SqlConnection(" server=(local); Trusted_Connect ion=true;databa se=pubs;")

Try
cn.Open()
cn.Close() ' make sure it is closed before entering finally
block (if no error, that is)
Finally
' debugger will move to cn.Close() even though it is not Open
If Not cn Is Nothing AndAlso cn.State = ConnectionState .Open
Then cn.Close()
End Try

End Sub
End Class

Greg

"Cor Ligthert" <no**********@p lanet.nl> wrote in message
news:up******** ******@TK2MSFTN GP12.phx.gbl...

Hi guys,

I made this test and in my opinion it goes as it should go, where did I go
wrong?

Cor
\\\
public class doedoe
Public shared sub Main
Dim dataobjects As New mycl
Dim verified As Boolean = True
If verified = False Then dataobjects.Has Error = True
If Not dataobjects Is Nothing AndAlso dataobjects.Has Error = False
Then
MessageBox.Show ("should be right")
End If
End Sub
End Class
Public Class mycl
Private mHasError As Boolean
Public Property HasError() As Boolean
Get
Return mHasError
End Get
Set(ByVal Value As Boolean)
mHasError = Value
End Set
End Property
///

[Cor Ligthert]

Greg
I tried this and no strange results

\\\
Dim cn As New OleDb.OleDbConn ection("Provide r=Microsoft.Jet .OLEDB.4.0;Data
Source=C:\whate ver.mdb")
cn.Open()
cn.Close()
Try
Catch ex As Exception
Finally
If Not cn Is Nothing AndAlso cn.State = ConnectionState .Open
Then
MessageBox.Show ("Is showed when cn.close is disabled")
End If
End Try
///

[Greg Burns]

No, you got to do my example. The problem is when If Then is one line, no
End If.

You won't be able to throw in a messagebox like you are trying. You will
have to step through with the debugger.

If Not cn Is Nothing AndAlso cn.State = ConnectionState .Open Then cn.Close()
<-- all one line
Greg
"Cor Ligthert" <no**********@p lanet.nl> wrote in message
news:Ol******** ******@TK2MSFTN GP12.phx.gbl...

Greg
I tried this and no strange results

\\\
Dim cn As New OleDb.OleDbConn ection("Provide r=Microsoft.Jet .OLEDB.4.0;Data
Source=C:\whate ver.mdb")
cn.Open()
cn.Close()
Try
Catch ex As Exception
Finally
If Not cn Is Nothing AndAlso cn.State = ConnectionState .Open
Then
MessageBox.Show ("Is showed when cn.close is disabled")
End If
End Try
///

[Cor Ligthert]

Greg,

I changed it to this,

\\\
Dim cn As New OleDb.OleDbConn ection("Provide r=Microsoft.Jet .OLEDB.4.0;Data
Source=C:\whate ver.mdb")
cn.Open()
cn.Close()
Try
Catch ex As Exception
Finally
If Not cn Is Nothing AndAlso cn.State = ConnectionState .Open
Then cn.Close()
End Try
///
I have a different behaviour when I disable that first close.

Cor

No, you got to do my example. The problem is when If Then is one line, no
End If.

You won't be able to throw in a messagebox like you are trying. You will
have to step through with the debugger.

If Not cn Is Nothing AndAlso cn.State = ConnectionState .Open Then cn.Close() <-- all one line
Greg
"Cor Ligthert" <no**********@p lanet.nl> wrote in message
news:Ol******** ******@TK2MSFTN GP12.phx.gbl...

Greg
I tried this and no strange results

\\\
Dim cn As New OleDb.OleDbConn ection("Provide r=Microsoft.Jet .OLEDB.4.0;Data Source=C:\whate ver.mdb")
cn.Open()
cn.Close()
Try
Catch ex As Exception
Finally
If Not cn Is Nothing AndAlso cn.State = ConnectionState .Open
Then
MessageBox.Show ("Is showed when cn.close is disabled")
End If
End Try
///

[Cor Ligthert]

Greg,

It was exactly as you said yesterday what you said and thought that I got
not that behaviour, tomorrow I get it, with this as well,
\\\
Try
Catch ex As Exception
Finally
If 0 = 1 Then MessageBox.Show ("hello")
End Try
///
And only in the Finnally block, and it will not be exectuted, it shows it is
executed.

In your example it can be the right situation when this error on the open.
However in this case, when I set it in a three line If statement, it behaves
in another way as you said, crazy.

Cor

I just tried you exact code and it behaves the same whether I disable the
first close or not.

Understand, nobody is disputing that if the connection is already closed it will NOT try and close it again. The code works properly.

It is simpy this; if you step through with the debugger it ALWAYS highlights that cn.Close on the other side of the Then. It appears that it is
exectuing it, whether it is or not.

Make sense? I added a screen shot (and simplified the If expression)

Greg

"Cor Ligthert" <no**********@p lanet.nl> wrote in message
news:OW******** ******@TK2MSFTN GP12.phx.gbl...

Greg,

I changed it to this,

\\\
Dim cn As New OleDb.OleDbConn ection("Provide r=Microsoft.Jet .OLEDB.4.0;Data Source=C:\whate ver.mdb")
cn.Open()
cn.Close()
Try
Catch ex As Exception
Finally
If Not cn Is Nothing AndAlso cn.State = ConnectionState .Open
Then cn.Close()
End Try
///
I have a different behaviour when I disable that first close.

Cor

No, you got to do my example. The problem is when If Then is one line,
no
End If.

You won't be able to throw in a messagebox like you are trying. You will have to step through with the debugger.

If Not cn Is Nothing AndAlso cn.State = ConnectionState .Open Then

cn.Close()

<-- all one line
Greg
"Cor Ligthert" <no**********@p lanet.nl> wrote in message
news:Ol******** ******@TK2MSFTN GP12.phx.gbl...
> Greg
> I tried this and no strange results
>
> \\\
> Dim cn As New

OleDb.OleDbConn ection("Provide r=Microsoft.Jet .OLEDB.4.0;Data

> Source=C:\whate ver.mdb")
> cn.Open()
> cn.Close()
> Try
> Catch ex As Exception
> Finally
> If Not cn Is Nothing AndAlso cn.State = ConnectionState .Open > Then
> MessageBox.Show ("Is showed when cn.close is disabled")
> End If
> End Try
> ///
>
>