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hi
a function called Save() saves user input to database
should i write try catch block like this
private void Save()
{
try
{
}
catch (SqlException sqlEx)
{
MessageBox.Show(sqlEx.Message);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
or should i write it like this in the function or event handler that calls Save();
try
{
Save();
}
catch (SqlException sqlEx)
{
MessageBox.Show(sqlEx.Message);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
and what is the difference, if there was a difference
and which is a better coding practice
thanks
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It depends on what you're going to do with the exception. If the exception is of no consequence to external code and can be handled within the Save method itself, then keep the try/catch in there.
If the calling code may (now or in the future) want to do something depending on the exception then wrap the Save in the calling code.
The second way is more flexible in the long term IMO. If you decide to use the first then it may be worth changing the Save to return a bool to indicate success or failure to the calling code so it still has the option of retrying the Save operation.
DaveIf this helped, please vote & accept answer!
Binging is like googling, it just feels dirtier. (Pete O'Hanlon)
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
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DaveyM69 wrote: If the exception is of no consequence to external code
my english is not very good, i don't get what you mean by this
by the way i'm using llblgen
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I mean if the calling code will be able to continue regardless of specific exceptions then it's safe to catch these inside the save.
DaveIf this helped, please vote & accept answer!
Binging is like googling, it just feels dirtier. (Pete O'Hanlon)
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
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If "Save" can throw (or cause) exceptions that you can handle locally, then surround the method with a catch-block. Don't accomodate for exceptions that you cannot recover from - a "catch Exception" will also catch a EOutOfMemory - a general error that would best be handled in the global exception handler.
--edit--
I'm using the tooltips from intellisense to determine what exceptions to expect. Enter "System.IO.File.Re", and press <Ctrl>-<space>, and intellisense will pop up with the method ReadAllBytes. It also shows a tooltip, with a prototype of the method and a list of exceptions that the method can throw.
If there's anything in the list that you can handle, then do so. All other things should be left to the errorhandler[^].
I are Troll 
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The answer, of course, is it depends on many factors.
In your first option the Save() method should take some action if it catches an exception and then return a status to its calling method to tell it whether the function succeeded or not. However, in the second sample the calling method is expected to understand an SQL exception, whereas it should really only be expected to handle "Save exceptions". So in this case sample one is probably the better choice.
txtspeak is the realm of 9 year old children, not developers. Christian Graus
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the problem is that many exceptions are expected and returning a bool value is not enought to descripe
what error has been caught, so i need to handle in the function that calls save
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Hussam Fattahi wrote: i need to handle in the function that calls save
That's fine, I was only offering suggestions based on your original post. It all comes down to knowing what your program is doing and how it needs to react to exceptions. Only you can really decide where is the best place, based on your understanding of the code.
txtspeak is the realm of 9 year old children, not developers. Christian Graus
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thanks, your help is greetly appreciated
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Hussam Fattahi wrote: the problem is that many exceptions are expected and returning a bool value is not enought to descripe
what error has been caught, so i need to handle in the function that calls save
There is (probably) more than one place where you "save" data. Some things can be handled locally; you might want to handle a "reconnect" to the database and execute the query again. That's the thing that you should catch. All other things should be allowed to pass by.
You'd want two things to happen when an exception occurs; the user needs to know, and someone might be interested in the details of the exception later on.
First things first, the user needs to be informed that something went wrong. That's where the general error-handler comes in, it's a special event that traps all unhandled exceptions. From there you can show a message - without a stacktrace, explaining what went wrong in layman-terms, and explaining what countermeasures can be taken. This way, the user gets a "Disk Full" message, without every programmer checking each method individually and displaying their own windows. It's quite easy to display a helpfull message for the most common ones and to redirect the user to a helpfull webpage.
You'd probably want to log all the exceptions that you didn't handle; these should be treated as bugs. Log4Net could help you out there 
I are Troll
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You shouldn't do this:
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
unless you have a very good reason (e.g. this is a top-level exception handler). It is considered bad practise, you should catch known exception types, the code you have will "hide" unexpected exceptions (from testing etc).
Dalek Dave: There are many words that some find offensive, Homosexuality, Alcoholism, Religion, Visual Basic, Manchester United, Butter.
Pete o'Hanlon: If it wasn't insulting tools, I'd say you were dumber than a bag of spanners.
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i thought exception hiding is doing like this
catch (Exception ex)
{
}
and i'm not sure what specific exception will happen so i used the general exception
thanks
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An approach could be to put the SQLException within the Save() method and the general exception outside - that way SQLExceptions are caught in the Save method and anything else outside.
Me, I'm dishonest. And a dishonest man you can always trust to be dishonest.
Honestly. It's the honest ones you want to watch out for...
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In the example given, the second way is probably better -- I wouldn't want to call your Save method from a Windows Service and have it try to pop up a message.
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Hi all,
I have two users on my system. On one user I could edit the Key HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies
But on second user I could not do so. Just getting the error message
"Cannot create value: Error writing to the registry.".
When I tried to change permissions on above key, I get error message
"Unable to save permission changes on Policies.Access is denied.".
I am wondering why same user cannot change its own above registry key. Can somebody help me please how to do so via both "Registry Editor" and via a program in C#?
Second help I need is How to change above key of a different user (I mean changing above key of user A from user B's logged-in session) programmatically (preferably via C#).
I am trying this on XP right now but will need to run my program on XP, VISTA and Windows 7.
If somebody knows how to go about it, please help me in that.
Thanks in Advance
Best Regards
Aseem
modified on Sunday, March 28, 2010 5:34 AM
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You did not say which version of Windows you are running on, but this is probably a permissions issue. Try running the program with Administrator privilege and see if that fixes the issue.
txtspeak is the realm of 9 year old children, not developers. Christian Graus
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Dear All,
I need to know whether Entity Framework works with all of the major database server like- sql, oracle, mysql
and so on.
mir
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mmdullah wrote: all of the major database server like- sql
No, Microsoft made an object relational mapping database tool that does not work with any know database 
I know the language. I've read a book. - _Madmatt
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Dear All,
There are numerous sample of SMS sending and reading on web.
But I need to dial a mobile phone and a conversation period .
In this period I want to record the conversation .
Would you please give me any idea?
Mir
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Have you tried to write or plan any code? How can we help you if you've not done some steps?
If the post was helpful, please vote, eh!
Current activities:
Book: Devils by Fyodor Dostoyevsky
Project: Hospital Automation, final stage
Learning: Image analysis, LINQ
Now and forever, defiant to the end.
What is Multiple Sclerosis[ ^]?
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mmdullah wrote: Would you please give me any idea?
Search for "TAPI"
I are Troll
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