Custom Error Handling

[Steve Amey]

Hi all

I want to be able to throw a custom error up the call stack. I have looked
around and it seems as though it's possible, but I can't get it to work
:o( Below is some sample code.

------------------------------------------------------------
Public Class MainForm
Public Sub Show Form
Try
Dim f As New Form1
f.Show
Catch Ex As MyCustomExcepti on
'// Handle the custom exception
Finally
'// Clean-up
End Try
End Sub
End Class

Public Class Form1
Public Sub New()
MyBase.New
'This call is required by the Windows Form Designer.
InitializeCompo nent()
'Add any initialization after the InitializeCompo nent() call
Try
'// Perform some stuff that might encounter an error
Catch Ex As Exception
Throw New MyCustomExcepti on '// I want to throw my exception up to
MainForm
End Try
End Sub
End Class
--------------------------------------------------------------

In the Sub New I will be getting information from a database and also doing
other things, these could result in an Exception. I want to be able to trap
the exception, and then create a new custom exception and have that thrown
up the call stack to the MainForm which would deal with it. If I try to
Throw my custom exception at the moment, the Catch Ex As MyCustomExcepti on
does not execute, if I put in a Catch Ex As Exception, then that will
execute.

How do I throw my custom object (which inherits from Exception) and then
catch that object up the call stack.

Regards,
Steve.

[Steve Amey]

Hiya

I have just noticed that my Custom Exception is being added in to an
Exception Object as the Inner Exception. Eg. Ex.InnerExcepti on =
MyCustomExcepti on

How woud I get my Exception to be the top most Exception? So Ex =
MyCustomExcepti on.

Regards,
Steve.

"Steve Amey" <stevea@centuri on-ms_RemoveThis_. co.uk> wrote in message
news:eg******** ******@TK2MSFTN GP14.phx.gbl...

Hi all

I want to be able to throw a custom error up the call stack. I have looked
around and it seems as though it's possible, but I can't get it to work
:o( Below is some sample code.

------------------------------------------------------------
Public Class MainForm
Public Sub Show Form
Try
Dim f As New Form1
f.Show
Catch Ex As MyCustomExcepti on
'// Handle the custom exception
Finally
'// Clean-up
End Try
End Sub
End Class

Public Class Form1
Public Sub New()
MyBase.New
'This call is required by the Windows Form Designer.
InitializeCompo nent()
'Add any initialization after the InitializeCompo nent() call
Try
'// Perform some stuff that might encounter an error
Catch Ex As Exception
Throw New MyCustomExcepti on '// I want to throw my exception up to
MainForm
End Try
End Sub
End Class
--------------------------------------------------------------

In the Sub New I will be getting information from a database and also doing other things, these could result in an Exception. I want to be able to trap the exception, and then create a new custom exception and have that thrown
up the call stack to the MainForm which would deal with it. If I try to
Throw my custom exception at the moment, the Catch Ex As MyCustomExcepti on
does not execute, if I put in a Catch Ex As Exception, then that will
execute.

How do I throw my custom object (which inherits from Exception) and then
catch that object up the call stack.

Regards,
Steve.

[Jay B. Harlow [MVP - Outlook]]

Steve,
Which version of VS.NET? With VS.NET 2003 I am not able to reproduce your
problem.

What exception are you seeing instead of MyCustomExcepti on?

I would recommend including the exception you caught as an inner exception
when you throw a new MyCustomExcepti on.

Hope this helps
Jay

"Steve Amey" <stevea@centuri on-ms_RemoveThis_. co.uk> wrote in message
news:eg******** ******@TK2MSFTN GP14.phx.gbl...

Hi all

I want to be able to throw a custom error up the call stack. I have looked
around and it seems as though it's possible, but I can't get it to work
:o( Below is some sample code.

------------------------------------------------------------
Public Class MainForm
Public Sub Show Form
Try
Dim f As New Form1
f.Show
Catch Ex As MyCustomExcepti on
'// Handle the custom exception
Finally
'// Clean-up
End Try
End Sub
End Class

Public Class Form1
Public Sub New()
MyBase.New
'This call is required by the Windows Form Designer.
InitializeCompo nent()
'Add any initialization after the InitializeCompo nent() call
Try
'// Perform some stuff that might encounter an error
Catch Ex As Exception
Throw New MyCustomExcepti on '// I want to throw my exception up to
MainForm
End Try
End Sub
End Class
--------------------------------------------------------------

In the Sub New I will be getting information from a database and also
doing
other things, these could result in an Exception. I want to be able to
trap
the exception, and then create a new custom exception and have that thrown
up the call stack to the MainForm which would deal with it. If I try to
Throw my custom exception at the moment, the Catch Ex As MyCustomExcepti on
does not execute, if I put in a Catch Ex As Exception, then that will
execute.

How do I throw my custom object (which inherits from Exception) and then
catch that object up the call stack.

Regards,
Steve.

[Steve Amey]

Hi Jay

I am using 2003, but it appears to be working now! I've lost count the
amount of times something doesn't work but suddenly does the next day :o)

I am having 1 more difficulty though, when I populate my custom exception I
set the properties such as Message, InnerException etc... but when the
exception is shown the message simply reads 'Error in the application'. When
I step through the code I set the properties, and I can see the module level
variables change, but the property doesn't. The Properties have to be
declared as Shadows, is this the reason the Message is not being displayed
correctly?

Here is the code for my Class:
-----------------------------------------------
Public Class MyCustomExcepti on
Inherits ApplicationExce ption

Public Sub New(ByVal Ex As Exception)
With Me
..InnerExceptio n = Ex
..Message = Ex.Message.ToSt ring
..Source = Ex.Source.ToStr ing
..StackTrace = Ex.StackTrace.T oString
..TargetSite = Ex.TargetSite
..HelpLink = Ex.HelpLink
End With
End Sub

Public Sub New(ByVal Ex As Exception, ByVal dataSet As DataSet)
With Me
..InnerExceptio n = Ex
..Message = Ex.Message.ToSt ring
..Source = Ex.Source.ToStr ing
..StackTrace = Ex.StackTrace.T oString
..TargetSite = Ex.TargetSite
..HelpLink = Ex.HelpLink
..DataSet = dataSet
End With
End Sub

Public Shadows Property InnerException( ) As Exception
Get
Return m_InnerExceptio n
End Get
Set(ByVal Value As Exception)
m_InnerExceptio n = Value
End Set
End Property

Public Overrides Property Source() As String
Get
Return m_Source
End Get
Set(ByVal Value As String)
m_Source = Value
End Set
End Property

Public Shadows Property Message() As String
Get
Return m_Message
End Get
Set(ByVal Value As String)
m_Message = Value
End Set
End Property

Public Shadows Property TargetSite() As Reflection.Meth odBase
Get
Return m_TargetSite
End Get
Set(ByVal Value As Reflection.Meth odBase)
m_TargetSite = Value
End Set
End Property

Public Shadows Property StackTrace() As String
Get
Return m_StackTrace
End Get
Set(ByVal Value As String)
m_StackTrace = Value
End Set
End Property

Public Shadows Property HelpLink() As String
Get
Return m_HelpLink
End Get
Set(ByVal Value As String)
m_HelpLink = Value
End Set
End Property

Public Property DataSet() As DataSet
Get
Return m_oDataSet
End Get
Set(ByVal Value As DataSet)
m_oDataSet = Value
End Set
End Property

End Class
-----------------------------------------------------

So when I read the MyCustomExcepti on.Message property, it doesn't return the
value in m_Message but returns the text I described above.

Regards,
Steve

"Jay B. Harlow [MVP - Outlook]" <Ja************ @msn.com> wrote in message
news:eS******** ******@TK2MSFTN GP14.phx.gbl...

Steve,
Which version of VS.NET? With VS.NET 2003 I am not able to reproduce your
problem.

What exception are you seeing instead of MyCustomExcepti on?

I would recommend including the exception you caught as an inner exception
when you throw a new MyCustomExcepti on.

Hope this helps
Jay

"Steve Amey" <stevea@centuri on-ms_RemoveThis_. co.uk> wrote in message
news:eg******** ******@TK2MSFTN GP14.phx.gbl...

Hi all

I want to be able to throw a custom error up the call stack. I have looked around and it seems as though it's possible, but I can't get it to work
:o( Below is some sample code.

------------------------------------------------------------
Public Class MainForm
Public Sub Show Form
Try
Dim f As New Form1
f.Show
Catch Ex As MyCustomExcepti on
'// Handle the custom exception
Finally
'// Clean-up
End Try
End Sub
End Class

Public Class Form1
Public Sub New()
MyBase.New
'This call is required by the Windows Form Designer.
InitializeCompo nent()
'Add any initialization after the InitializeCompo nent() call
Try
'// Perform some stuff that might encounter an error
Catch Ex As Exception
Throw New MyCustomExcepti on '// I want to throw my exception up to
MainForm
End Try
End Sub
End Class
--------------------------------------------------------------

In the Sub New I will be getting information from a database and also
doing
other things, these could result in an Exception. I want to be able to
trap
the exception, and then create a new custom exception and have that thrown up the call stack to the MainForm which would deal with it. If I try to
Throw my custom exception at the moment, the Catch Ex As MyCustomExcepti on does not execute, if I put in a Catch Ex As Exception, then that will
execute.

How do I throw my custom object (which inherits from Exception) and then
catch that object up the call stack.

Regards,
Steve.

[Jay B. Harlow [MVP - Outlook]]

Steve,

The Properties have to be
declared as Shadows, is this the reason the Message is not being displayed
correctly? Correct.

You should not Shadow base class members! Shadows is used primarily for
version control. For example: You release version one of your
MyCustomExcepti on with a specific method, MS release .NET 2.0 with the same
method in System.Applicat ionException, Shadows is used in this case to allow
you to continue using your method, while the base class can use its own
version of the method.

I was suggesting you pass the exception you caught to the base constructor:

Optionally I would allow users of the exception to specify a Message, and
not specify the innerException, something like:

Public Class MyCustomExcepti on
Inherits ApplicationExce ption

Private ReadOnly m_dataSet As DataSet

Public Sub New()
MyClass.New(Not hing, Nothing, Nothing)
End Sub

Public Sub New(ByVal message As String)
MyClass.New(mes sage, Nothing, Nothing)
End Sub

Public Sub New(ByVal innerException As Exception)
MyClass.New(Not hing, innerException, Nothing)
End Sub

Public Sub New(ByVal dataSet As DataSet)
MyClass.New(Not hing, Nothing, dataSet)
End Sub

Public Sub New(ByVal message As String, ByVal innerException As
Exception)
MyClass.New(mes sage, innerException, Nothing)
End Sub

Public Sub New(ByVal message As String, ByVal dataSet As DataSet)
MyClass.New(mes sage, Nothing, dataSet)
End Sub

Public Sub New(ByVal innerException As Exception, ByVal dataSet As
DataSet)
MyClass.New(Not hing, innerException, dataSet)
End Sub

Public Sub New(ByVal message As String, ByVal innerException As
Exception, ByVal dataSet As DataSet)
MyBase.New(mess age, innerException)
m_dataSet = dataSet
End Sub

Public ReadOnly Property DataSet() As DataSet
Get
Return m_dataSet
End Get
End Property

End Class

NOTE: The MyClass.New allows you to call another constructor on the same
class, while MyBase.New allows you to call a base constructor. I chain all
the constructors into one common constructor, then this common constructor
calls the base constructor. I do not show the special constructor required
for serialization.

The following article provides some good information on creating custom
Exception classes.

http://msdn.microsoft.com/library/de...rp08162001.asp

The example are in C#, however they should be easy enough to convert to
VB.NET.

Hope this helps
Jay
"Steve Amey" <stevea@centuri on-ms_RemoveThis_. co.uk> wrote in message
news:%2******** ********@TK2MSF TNGP12.phx.gbl. .. Hi Jay

I am using 2003, but it appears to be working now! I've lost count the
amount of times something doesn't work but suddenly does the next day :o)

I am having 1 more difficulty though, when I populate my custom exception
I
set the properties such as Message, InnerException etc... but when the
exception is shown the message simply reads 'Error in the application'.
When
I step through the code I set the properties, and I can see the module
level
variables change, but the property doesn't. The Properties have to be
declared as Shadows, is this the reason the Message is not being displayed
correctly?

Here is the code for my Class:
-----------------------------------------------
Public Class MyCustomExcepti on
Inherits ApplicationExce ption

Public Sub New(ByVal Ex As Exception)
With Me
.InnerException = Ex
.Message = Ex.Message.ToSt ring
.Source = Ex.Source.ToStr ing
.StackTrace = Ex.StackTrace.T oString
.TargetSite = Ex.TargetSite
.HelpLink = Ex.HelpLink
End With
End Sub

Public Sub New(ByVal Ex As Exception, ByVal dataSet As DataSet)
With Me
.InnerException = Ex
.Message = Ex.Message.ToSt ring
.Source = Ex.Source.ToStr ing
.StackTrace = Ex.StackTrace.T oString
.TargetSite = Ex.TargetSite
.HelpLink = Ex.HelpLink
.DataSet = dataSet
End With
End Sub

Public Shadows Property InnerException( ) As Exception
Get
Return m_InnerExceptio n
End Get
Set(ByVal Value As Exception)
m_InnerExceptio n = Value
End Set
End Property

Public Overrides Property Source() As String
Get
Return m_Source
End Get
Set(ByVal Value As String)
m_Source = Value
End Set
End Property

Public Shadows Property Message() As String
Get
Return m_Message
End Get
Set(ByVal Value As String)
m_Message = Value
End Set
End Property

Public Shadows Property TargetSite() As Reflection.Meth odBase
Get
Return m_TargetSite
End Get
Set(ByVal Value As Reflection.Meth odBase)
m_TargetSite = Value
End Set
End Property

Public Shadows Property StackTrace() As String
Get
Return m_StackTrace
End Get
Set(ByVal Value As String)
m_StackTrace = Value
End Set
End Property

Public Shadows Property HelpLink() As String
Get
Return m_HelpLink
End Get
Set(ByVal Value As String)
m_HelpLink = Value
End Set
End Property

Public Property DataSet() As DataSet
Get
Return m_oDataSet
End Get
Set(ByVal Value As DataSet)
m_oDataSet = Value
End Set
End Property

End Class
-----------------------------------------------------

So when I read the MyCustomExcepti on.Message property, it doesn't return
the
value in m_Message but returns the text I described above.

Regards,
Steve

"Jay B. Harlow [MVP - Outlook]" <Ja************ @msn.com> wrote in message
news:eS******** ******@TK2MSFTN GP14.phx.gbl...

Steve,
Which version of VS.NET? With VS.NET 2003 I am not able to reproduce your
problem.

What exception are you seeing instead of MyCustomExcepti on?

I would recommend including the exception you caught as an inner
exception
when you throw a new MyCustomExcepti on.

Hope this helps
Jay

"Steve Amey" <stevea@centuri on-ms_RemoveThis_. co.uk> wrote in message
news:eg******** ******@TK2MSFTN GP14.phx.gbl...

> Hi all
>
> I want to be able to throw a custom error up the call stack. I have looked > around and it seems as though it's possible, but I can't get it to work
> :o( Below is some sample code.
>
> ------------------------------------------------------------
> Public Class MainForm
> Public Sub Show Form
> Try
> Dim f As New Form1
> f.Show
> Catch Ex As MyCustomExcepti on
> '// Handle the custom exception
> Finally
> '// Clean-up
> End Try
> End Sub
> End Class
>
> Public Class Form1
> Public Sub New()
> MyBase.New
> 'This call is required by the Windows Form Designer.
> InitializeCompo nent()
> 'Add any initialization after the InitializeCompo nent() call
> Try
> '// Perform some stuff that might encounter an error
> Catch Ex As Exception
> Throw New MyCustomExcepti on '// I want to throw my exception up to
> MainForm
> End Try
> End Sub
> End Class
> --------------------------------------------------------------
>
> In the Sub New I will be getting information from a database and also
> doing
> other things, these could result in an Exception. I want to be able to
> trap
> the exception, and then create a new custom exception and have that thrown > up the call stack to the MainForm which would deal with it. If I try to
> Throw my custom exception at the moment, the Catch Ex As MyCustomExcepti on > does not execute, if I put in a Catch Ex As Exception, then that will
> execute.
>
> How do I throw my custom object (which inherits from Exception) and
> then
> catch that object up the call stack.
>
> Regards,
> Steve.
>
>

[Jay B. Harlow [MVP - Outlook]]

Steve,
I should add, you can override either (or both) the Exception.Messa ge
property & Exception.ToStr ing, if you want to include details from the
dataset, when Exception.Messa ge is displayed or Exception.ToStr ing is used.

Normally I use Exception.Messa ge when I am displaying the exception to the
user, while I use Exception.ToStr ing when I am logging the exception in my
Global Exception Handler.

Hope this helps
Jay
"Steve Amey" <stevea@centuri on-ms_RemoveThis_. co.uk> wrote in message
news:%2******** ********@TK2MSF TNGP12.phx.gbl. ..

Hi Jay

I am using 2003, but it appears to be working now! I've lost count the
amount of times something doesn't work but suddenly does the next day :o)

I am having 1 more difficulty though, when I populate my custom exception
I
set the properties such as Message, InnerException etc... but when the
exception is shown the message simply reads 'Error in the application'.
When
I step through the code I set the properties, and I can see the module
level
variables change, but the property doesn't. The Properties have to be
declared as Shadows, is this the reason the Message is not being displayed
correctly?

Here is the code for my Class:
-----------------------------------------------
Public Class MyCustomExcepti on
Inherits ApplicationExce ption

Public Sub New(ByVal Ex As Exception)
With Me
.InnerException = Ex
.Message = Ex.Message.ToSt ring
.Source = Ex.Source.ToStr ing
.StackTrace = Ex.StackTrace.T oString
.TargetSite = Ex.TargetSite
.HelpLink = Ex.HelpLink
End With
End Sub

Public Sub New(ByVal Ex As Exception, ByVal dataSet As DataSet)
With Me
.InnerException = Ex
.Message = Ex.Message.ToSt ring
.Source = Ex.Source.ToStr ing
.StackTrace = Ex.StackTrace.T oString
.TargetSite = Ex.TargetSite
.HelpLink = Ex.HelpLink
.DataSet = dataSet
End With
End Sub

Public Shadows Property InnerException( ) As Exception
Get
Return m_InnerExceptio n
End Get
Set(ByVal Value As Exception)
m_InnerExceptio n = Value
End Set
End Property

Public Overrides Property Source() As String
Get
Return m_Source
End Get
Set(ByVal Value As String)
m_Source = Value
End Set
End Property

Public Shadows Property Message() As String
Get
Return m_Message
End Get
Set(ByVal Value As String)
m_Message = Value
End Set
End Property

Public Shadows Property TargetSite() As Reflection.Meth odBase
Get
Return m_TargetSite
End Get
Set(ByVal Value As Reflection.Meth odBase)
m_TargetSite = Value
End Set
End Property

Public Shadows Property StackTrace() As String
Get
Return m_StackTrace
End Get
Set(ByVal Value As String)
m_StackTrace = Value
End Set
End Property

Public Shadows Property HelpLink() As String
Get
Return m_HelpLink
End Get
Set(ByVal Value As String)
m_HelpLink = Value
End Set
End Property

Public Property DataSet() As DataSet
Get
Return m_oDataSet
End Get
Set(ByVal Value As DataSet)
m_oDataSet = Value
End Set
End Property

End Class
-----------------------------------------------------

So when I read the MyCustomExcepti on.Message property, it doesn't return
the
value in m_Message but returns the text I described above.

Regards,
Steve

"Jay B. Harlow [MVP - Outlook]" <Ja************ @msn.com> wrote in message
news:eS******** ******@TK2MSFTN GP14.phx.gbl...

Steve,
Which version of VS.NET? With VS.NET 2003 I am not able to reproduce your
problem.

What exception are you seeing instead of MyCustomExcepti on?

I would recommend including the exception you caught as an inner
exception
when you throw a new MyCustomExcepti on.

Hope this helps
Jay

"Steve Amey" <stevea@centuri on-ms_RemoveThis_. co.uk> wrote in message
news:eg******** ******@TK2MSFTN GP14.phx.gbl...

> Hi all
>
> I want to be able to throw a custom error up the call stack. I have looked > around and it seems as though it's possible, but I can't get it to work
> :o( Below is some sample code.
>
> ------------------------------------------------------------
> Public Class MainForm
> Public Sub Show Form
> Try
> Dim f As New Form1
> f.Show
> Catch Ex As MyCustomExcepti on
> '// Handle the custom exception
> Finally
> '// Clean-up
> End Try
> End Sub
> End Class
>
> Public Class Form1
> Public Sub New()
> MyBase.New
> 'This call is required by the Windows Form Designer.
> InitializeCompo nent()
> 'Add any initialization after the InitializeCompo nent() call
> Try
> '// Perform some stuff that might encounter an error
> Catch Ex As Exception
> Throw New MyCustomExcepti on '// I want to throw my exception up to
> MainForm
> End Try
> End Sub
> End Class
> --------------------------------------------------------------
>
> In the Sub New I will be getting information from a database and also
> doing
> other things, these could result in an Exception. I want to be able to
> trap
> the exception, and then create a new custom exception and have that thrown > up the call stack to the MainForm which would deal with it. If I try to
> Throw my custom exception at the moment, the Catch Ex As MyCustomExcepti on > does not execute, if I put in a Catch Ex As Exception, then that will
> execute.
>
> How do I throw my custom object (which inherits from Exception) and
> then
> catch that object up the call stack.
>
> Regards,
> Steve.
>
>

[Steve Amey]

Hi Jay

Thank you very much for your help, it's much appreciated!

Kind Regards,
Steve

"Jay B. Harlow [MVP - Outlook]" <Ja************ @msn.com> wrote in message
news:eg******** *****@TK2MSFTNG P11.phx.gbl...

Steve,
I should add, you can override either (or both) the Exception.Messa ge
property & Exception.ToStr ing, if you want to include details from the
dataset, when Exception.Messa ge is displayed or Exception.ToStr ing is used.
Normally I use Exception.Messa ge when I am displaying the exception to the
user, while I use Exception.ToStr ing when I am logging the exception in my
Global Exception Handler.

Hope this helps
Jay
"Steve Amey" <stevea@centuri on-ms_RemoveThis_. co.uk> wrote in message
news:%2******** ********@TK2MSF TNGP12.phx.gbl. ..

Hi Jay

I am using 2003, but it appears to be working now! I've lost count the
amount of times something doesn't work but suddenly does the next day :o)
I am having 1 more difficulty though, when I populate my custom exception I
set the properties such as Message, InnerException etc... but when the
exception is shown the message simply reads 'Error in the application'.
When
I step through the code I set the properties, and I can see the module
level
variables change, but the property doesn't. The Properties have to be
declared as Shadows, is this the reason the Message is not being displayed correctly?

Here is the code for my Class:
-----------------------------------------------
Public Class MyCustomExcepti on
Inherits ApplicationExce ption

Public Sub New(ByVal Ex As Exception)
With Me
.InnerException = Ex
.Message = Ex.Message.ToSt ring
.Source = Ex.Source.ToStr ing
.StackTrace = Ex.StackTrace.T oString
.TargetSite = Ex.TargetSite
.HelpLink = Ex.HelpLink
End With
End Sub

Public Sub New(ByVal Ex As Exception, ByVal dataSet As DataSet)
With Me
.InnerException = Ex
.Message = Ex.Message.ToSt ring
.Source = Ex.Source.ToStr ing
.StackTrace = Ex.StackTrace.T oString
.TargetSite = Ex.TargetSite
.HelpLink = Ex.HelpLink
.DataSet = dataSet
End With
End Sub

Public Shadows Property InnerException( ) As Exception
Get
Return m_InnerExceptio n
End Get
Set(ByVal Value As Exception)
m_InnerExceptio n = Value
End Set
End Property

Public Overrides Property Source() As String
Get
Return m_Source
End Get
Set(ByVal Value As String)
m_Source = Value
End Set
End Property

Public Shadows Property Message() As String
Get
Return m_Message
End Get
Set(ByVal Value As String)
m_Message = Value
End Set
End Property

Public Shadows Property TargetSite() As Reflection.Meth odBase
Get
Return m_TargetSite
End Get
Set(ByVal Value As Reflection.Meth odBase)
m_TargetSite = Value
End Set
End Property

Public Shadows Property StackTrace() As String
Get
Return m_StackTrace
End Get
Set(ByVal Value As String)
m_StackTrace = Value
End Set
End Property

Public Shadows Property HelpLink() As String
Get
Return m_HelpLink
End Get
Set(ByVal Value As String)
m_HelpLink = Value
End Set
End Property

Public Property DataSet() As DataSet
Get
Return m_oDataSet
End Get
Set(ByVal Value As DataSet)
m_oDataSet = Value
End Set
End Property

End Class
-----------------------------------------------------

So when I read the MyCustomExcepti on.Message property, it doesn't return
the
value in m_Message but returns the text I described above.

Regards,
Steve

"Jay B. Harlow [MVP - Outlook]" <Ja************ @msn.com> wrote in message news:eS******** ******@TK2MSFTN GP14.phx.gbl...

Steve,
Which version of VS.NET? With VS.NET 2003 I am not able to reproduce your problem.

What exception are you seeing instead of MyCustomExcepti on?

I would recommend including the exception you caught as an inner
exception
when you throw a new MyCustomExcepti on.

Hope this helps
Jay

"Steve Amey" <stevea@centuri on-ms_RemoveThis_. co.uk> wrote in message
news:eg******** ******@TK2MSFTN GP14.phx.gbl...
> Hi all
>
> I want to be able to throw a custom error up the call stack. I have

looked

> around and it seems as though it's possible, but I can't get it to work > :o( Below is some sample code.
>
> ------------------------------------------------------------
> Public Class MainForm
> Public Sub Show Form
> Try
> Dim f As New Form1
> f.Show
> Catch Ex As MyCustomExcepti on
> '// Handle the custom exception
> Finally
> '// Clean-up
> End Try
> End Sub
> End Class
>
> Public Class Form1
> Public Sub New()
> MyBase.New
> 'This call is required by the Windows Form Designer.
> InitializeCompo nent()
> 'Add any initialization after the InitializeCompo nent() call
> Try
> '// Perform some stuff that might encounter an error
> Catch Ex As Exception
> Throw New MyCustomExcepti on '// I want to throw my exception up to > MainForm
> End Try
> End Sub
> End Class
> --------------------------------------------------------------
>
> In the Sub New I will be getting information from a database and also
> doing
> other things, these could result in an Exception. I want to be able to > trap
> the exception, and then create a new custom exception and have that

thrown

> up the call stack to the MainForm which would deal with it. If I try to > Throw my custom exception at the moment, the Catch Ex As

MyCustomExcepti on

> does not execute, if I put in a Catch Ex As Exception, then that will
> execute.
>
> How do I throw my custom object (which inherits from Exception) and
> then
> catch that object up the call stack.
>
> Regards,
> Steve.
>
>