"Crouchie1998" <crouchie1***@discussions.microsoft.com> wrote in message
news:eEm8UtUNFHA.244@TK2MSFTNGP12.phx.gbl...
| Try
| ...
| Catch ex As Exception
|
|  MessageBox.Show(ex.ToString)
|
| End Try
|
| That will tell you exactly which type of exception you have then you can
| catch the exceptions more precisely.
|
| Try
| ...
| Catch ex As IO.FileIOException
|   ' Handle file access error
| Catch exx As Exception
|   ' Handle all other errors
| End Try
|
| You can also use 'IndexOf' too if you know the exact error message.
'Example
| Only' below:
|
| Dim sr As IO.StreamReader
|
| Try
|   sr = New IO.StreamReader("C:\zzzzz.txt")
|   sr.Read()
| Catch ex As Exception
|   If ex.ToString.IndexOf("Could not find file") > 0 Then
|      MessageBox.Show("File Not Found")
|   End If
| End Try
|
| If Not sr Is Nothing Then sr.Close()
|
|

"Jay B. Harlow [MVP - Outlook]" wrote:

> Crouchie,
> | You can also use 'IndexOf' too if you know the exact error message.
> 'Example
> | Only' below:
> I would not recommend using this approach as it does not localize very well.
>
> Hope this helps
> Jay
>
>
> "Crouchie1998" <crouchie1***@discussions.microsoft.com> wrote in message
> news:eEm8UtUNFHA.244@TK2MSFTNGP12.phx.gbl...
> | Try
> | ...
> | Catch ex As Exception
> |
> |  MessageBox.Show(ex.ToString)
> |
> | End Try
> |
> | That will tell you exactly which type of exception you have then you can
> | catch the exceptions more precisely.
> |
> | Try
> | ...
> | Catch ex As IO.FileIOException
> |   ' Handle file access error
> | Catch exx As Exception
> |   ' Handle all other errors
> | End Try
> |
> | You can also use 'IndexOf' too if you know the exact error message.
> 'Example
> | Only' below:
> |
> | Dim sr As IO.StreamReader
> |
> | Try
> |   sr = New IO.StreamReader("C:\zzzzz.txt")
> |   sr.Read()
> | Catch ex As Exception
> |   If ex.ToString.IndexOf("Could not find file") > 0 Then
> |      MessageBox.Show("File Not Found")
> |   End If
> | End Try
> |
> | If Not sr Is Nothing Then sr.Close()
> |
> |
>
>
>

"Dennis" <Den***@discussions.microsoft.com> wrote in message
news:DC100983-E789-4A83-B172-8BDDEF11E696@microsoft.com...
| Jay, this has no relevance to this thread but I noted that sr was returned
by
| VB.Net as nothing as are other VB.Net varibles that can't be initialized.
| This got me into the habit of returning nothing for reference type
variables
| from some of my routines when something couldn't be found.  For example, I
do
| some work with reading and manipulating ID3 tags from mp3 files and when
my
| routines can't find a tag item, the string is returned as nothing.
However,
| in every tag, I must check for either the tag isn't there or the text
| associated with the tag is "".  This is what made me wish that things like
| String.trim(x) would just return nothing when x is nothing!
|

"Jay B. Harlow [MVP - Outlook]" wrote:

> Dennis,
> | Jay, this has no relevance to this thread
> I take it you mean your comments has no relevance to which exception. ;-)
>
> | but I noted that sr was returned by
> | VB.Net as nothing
> What is "sr returned by VB.NET"?
>
> | as are other VB.Net varibles that can't be initialized.
> All VB.NET variables can be initialized! can you give me an example of one
> that cannot?
>
> | This got me into the habit of returning nothing for reference type
> variables
> | from some of my routines when something couldn't be found.
> Yes returning Nothing is handy sometimes, returning a "NullObject" is
> usually handier, aka Special Case pattern.
> http://www.martinfowler.com/eaaCatalog/specialCase.html
>
> | For example, I do
> | some work with reading and manipulating ID3 tags from mp3 files and when
> my
> | routines can't find a tag item, the string is returned as nothing.
> Do you need to know specifically if its not found? If I don't specifically
> need to know I will return String.Empty rather then Nothing, allowing me to
> use instance methods on the string as normal. I would consider throwing an
> exception for not found, especially if not found does not allow me to
> continue. I would consider returning Nothing if I needed to know
> specifically, but would then rather quickly change it to String.Empty to
> continue processing... I would consider using ByRef parameters to return a
> non-Nothing string & an boolean indicator if its found or not, however this
> feels like returning an object other then string (such as a ID3Tag class
> that I defined) that encapsulated the found string or String.Empty the fact
> none was found.
>
> Hope this helps
> Jay
>
>
> "Dennis" <Den***@discussions.microsoft.com> wrote in message
> news:DC100983-E789-4A83-B172-8BDDEF11E696@microsoft.com...
> | Jay, this has no relevance to this thread but I noted that sr was returned
> by
> | VB.Net as nothing as are other VB.Net varibles that can't be initialized.
> | This got me into the habit of returning nothing for reference type
> variables
> | from some of my routines when something couldn't be found.  For example, I
> do
> | some work with reading and manipulating ID3 tags from mp3 files and when
> my
> | routines can't find a tag item, the string is returned as nothing.
> However,
> | in every tag, I must check for either the tag isn't there or the text
> | associated with the tag is "".  This is what made me wish that things like
> | String.trim(x) would just return nothing when x is nothing!
> |
> <<xnip>>
>
>
>

"l.woods" <larry@NOSPAMlwoods.com> wrote in message
news:%23FxlThTNFHA.244@tk2msftngp13.phx.gbl...
|I want to set up my CATCH for a specific exception, but I really don't know
| which one of the multitude that it is.  I am getting the exception now
with
|
| Catch ex as Exception
|
| but I want to be more specific.  I can't find any property of  the
exception
| object that tells me WHICH one it is.
|
| TIA,
|
| Larry Woods
|
|

"Jay B. Harlow [MVP - Outlook]" <Jay_Harlow_***@msn.com> wrote in message
news:e2CysIUNFHA.3076@tk2msftngp13.phx.gbl...
> Larry,
> In addition to Larry's sample of:
>
>     Try
>         DoSomething()
>     Catch ex As Exception
>         If TypeOf ex Is SystemException Then
>             ' got a system exception
>         ElseIf TypeOf ex Is ApplicationException Then
>             ' got a application exception
>         Else
>             ' got another kind of exception
>         End If
>     End Try
>
> I prefer:
>
>     Try
>         DoSomething()
>     Catch ex As SystemException
>         ' got a system exception
>     Catch ex As ApplicationException
>         ' got a application exception
>     Catch ex As Exception
>         ' got another kind of exception
>     End Try
>
> Remember on both to list derived exceptions before base exceptions. As the
> first class that matches is the handler that will be used.
>
>
> I prefer the second, as its 'cleaner' and it allows you to only catch the
> specific exception you want, while ignoring unwanted exceptions. For
> example:
>
>     Try
>         DoSomething()
>     Catch ex As FileNotFoundException
>         ' got a file not found exceptoin
>     End Try
>
> Will only catch FileNotFoundExceptions, other exceptions will continue
> upward to another exception handler...
>
> Another useful tidbit to limit what exceptions are caught is the When
> clause. For example:
>
>     Dim request As HttpWebRequest
>     Dim response As HttpWebResponse
>     Try
>         response = DirectCast(request.GetResponse(), HttpWebResponse)
>     Catch ex As WebException When TypeOf ex.Response Is HttpWebResponse
>         response = DirectCast(ex.Response, HttpWebResponse)
>     End Try
>
> The catch block will only handle WebExceptions that have a Reponse type of
> HttpWebResponse.
>
> Hope this helps
> Jay
>
>
> "l.woods" <larry@NOSPAMlwoods.com> wrote in message
> news:%23FxlThTNFHA.244@tk2msftngp13.phx.gbl...
> |I want to set up my CATCH for a specific exception, but I really don't
know
> | which one of the multitude that it is.  I am getting the exception now
> with
> |
> | Catch ex as Exception
> |
> | but I want to be more specific.  I can't find any property of  the
> exception
> | object that tells me WHICH one it is.
> |
> | TIA,
> |
> | Larry Woods
> |
> |
>
>

"l.woods" <larry@NOSPAMlwoods.com> wrote in message
news:eMjbjDROFHA.1172@TK2MSFTNGP12.phx.gbl...
| Thanks to all....
|
| In my situation, what I was looking for will probably be solved by the
| "MessageBox.Show (ex.ToString).  My problem was that I was getting an
| exception, and I wanted to know exactly WHICH exception it was so that I
| could recode and check for that exception specifically.  The ex.ToSting
will
| hopefully give that information to me.
|
| Larry Woods
|
| "Jay B. Harlow [MVP - Outlook]" <Jay_Harlow_***@msn.com> wrote in message
| news:e2CysIUNFHA.3076@tk2msftngp13.phx.gbl...
| > Larry,
| > In addition to Larry's sample of:
| >
| >     Try
| >         DoSomething()
| >     Catch ex As Exception
| >         If TypeOf ex Is SystemException Then
| >             ' got a system exception
| >         ElseIf TypeOf ex Is ApplicationException Then
| >             ' got a application exception
| >         Else
| >             ' got another kind of exception
| >         End If
| >     End Try
| >
| > I prefer:
| >
| >     Try
| >         DoSomething()
| >     Catch ex As SystemException
| >         ' got a system exception
| >     Catch ex As ApplicationException
| >         ' got a application exception
| >     Catch ex As Exception
| >         ' got another kind of exception
| >     End Try
| >
| > Remember on both to list derived exceptions before base exceptions. As
the
| > first class that matches is the handler that will be used.
| >
| >
| > I prefer the second, as its 'cleaner' and it allows you to only catch
the
| > specific exception you want, while ignoring unwanted exceptions. For
| > example:
| >
| >     Try
| >         DoSomething()
| >     Catch ex As FileNotFoundException
| >         ' got a file not found exceptoin
| >     End Try
| >
| > Will only catch FileNotFoundExceptions, other exceptions will continue
| > upward to another exception handler...
| >
| > Another useful tidbit to limit what exceptions are caught is the When
| > clause. For example:
| >
| >     Dim request As HttpWebRequest
| >     Dim response As HttpWebResponse
| >     Try
| >         response = DirectCast(request.GetResponse(), HttpWebResponse)
| >     Catch ex As WebException When TypeOf ex.Response Is HttpWebResponse
| >         response = DirectCast(ex.Response, HttpWebResponse)
| >     End Try
| >
| > The catch block will only handle WebExceptions that have a Reponse type
of
| > HttpWebResponse.
| >
| > Hope this helps
| > Jay
| >
| >
| > "l.woods" <larry@NOSPAMlwoods.com> wrote in message
| > news:%23FxlThTNFHA.244@tk2msftngp13.phx.gbl...
| > |I want to set up my CATCH for a specific exception, but I really don't
| know
| > | which one of the multitude that it is.  I am getting the exception now
| > with
| > |
| > | Catch ex as Exception
| > |
| > | but I want to be more specific.  I can't find any property of  the
| > exception
| > | object that tells me WHICH one it is.
| > |
| > | TIA,
| > |
| > | Larry Woods
| > |
| > |
| >
| >
|
|