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Weeeelllll, what's stopping MS from throwing better exceptions? I've got some sample code I can give them on how to do it...
I don't want to have exception handling here as I believe a) that a majority of exceptions should be handled in the presentation layer and b) in this case it was a multi threading problem where we check if a key exists and add it if it does not exist but a second thread would insert causing the first to fail, making the need for explicit exception handling 'unobvious'. After fixing the multi threading problem the exception is fixed and I still don't have exception handling over the add method, won't have either.
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Be brave little warrior, be VERY brave
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Well, you didn't mention the multithreading issue at all in your first post, so in that case I would have wrapped the add in a lock so no two threads could check for and add data at the same time. In either case, you're still blindly trusting the data you're using and now you just admitted to blindly assuming that every operation you're doing on this data works in a multithreaded environment.
I'm just of the opinion that if you're going to bash someone's code, start with your own.
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I didn't realise this was a code bashing session, until now. You are going into semantics of the example, like I said I do not want to handle errors here (I want them to roll up to the presentation layer), and the lock statement is not the best solution here either. And yes, I am trusting the data I put into this as it is very controllod but I'm not doing it blindly, and I'm not blindly assuming anything because I'm expoecting the exception to be caught in the presentation layer. Now that I have found the problem and fixed it it works perfectly.
Another example: I've de-serialised some data and got an "Argument out of Range" exception, no idea which attribute of the object was out of range and no idea what the acceptable range is, and being Silverlight 3 the MSDN help files pointed me at an article for WPF which is not correct for SL 3 (the article mentioned an int where it was actually an Int16), if the message was "Argument 'asd' is out of range, maximum value is '32767'" it probably would have shaved 3 hours off my debugging.
I'm of the opinion that if you are going to suggest solutions make sure you understand the problem.
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Be brave little warrior, be VERY brave
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Adriaan Davel wrote: if the message was "Argument 'asd' is out of range, maximum value is '32767'" it probably would have shaved 3 hours off my debugging.
And if the object doesn't have a string representation?? Also, how is the exception going to know what the possible values are for a property that doesn't have "values"??
You want the exception to tailor itself to the property it's throw in and that's just not practical. The exception that MS provides works in the widest array of cases possible, where your exception message only works where a property is a value type.
Adriaan Davel wrote: I'm of the opinion that if you are going to suggest solutions make sure you understand the problem
I do understand the problem, and what it would take to get an exception to do what you want.
The point is, if you want a more meaningful message, wrap the property in it's own exception handler and throw a more meaningful message yourself, then catch that exception in your presentation layer.
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Dave Kreskowiak wrote: You want the exception to tailor itself to the property it's throw in and that's just not practical.
The exception will never know about the values, the code throwing the exception will. Surely there is a range validator that says something like if (value < 0 || value > 32767) throw new ArgumentOutRangeException(); which could be if (value < 0 || value > 32676) throw new ArgumentOutOfRangeException(0, 32767);. This has nothing to do with the string representation of an object...
Dave Kreskowiak wrote: You want the exception to tailor itself to the property it's throw in and that's just not practical
Exactly my point, its not practical to add exception handling to every interaction with the framework just to add detail, if the exception is thrown with more detail, it could make our lives much simpler.
Dave Kreskowiak wrote: where your exception message only works where a property is a value type.
Again your are talking about the specific example, I'm not
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Be brave little warrior, be VERY brave
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While that might provide useful information in your case, the framework could not guarantee that the key has a meaningful string representation or that the key is not confidential data.
If I ever used a custom object as the key (and that object has no real other reason to override ToString), the message would become 'The key "MyNamespace.MyCustomObject" has already been added to the dictionary', which is at best no better and at worst a little worse than the original error message.
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I think "MyNamespace.MyCustomObject" would have added value because I have a couple of dictionaries and a couple of parralel threads, it would certainly helped to narrow down the possibilities...
As for confidentiality, is any data on a developer machine in debugging mode confidential?
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Be brave little warrior, be VERY brave
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'The key "asd" has already been added to dictionary'
How would you recommend that Microsoft's error handler determine whether "asd" contains confidential information, or that the exception string wouldn't get logged in such a way as to compromise it?
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I would guess that a developer machine in debugging mode does not have confidential data on it, if a developer can step through it the confidentiality isn't very high at all, and in this example I struggle to see how a key would contain confidential data as its a reference pointer...
Probably difficult to make the call in this example (other that being in debug mode)
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Be brave little warrior, be VERY brave
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Adriaan Davel wrote: I would guess that a developer machine in debugging mode does not have confidential data on it
Hmm.... I wonder whether it would be worthwhile to have a SQL library support a connect-string option for whether to report detailed data in its error messages? I don't think the entity which is generating the exception messages has any way of knowing otherwise whether the machine issuing the queries is in debug mode, but adding a connect-string option shouldn't be out of the question. For maximum utility, a 'duplicate record' message should probably identify the table, column, and key values(*). Who knows--maybe such a thing already exists?
(*) Key values would have a high likelihood of holding confidential data, so they certainly should not be included unencrypted in error reports outside of debug contexts; to avoid parsing problems, they should probably be character-escaped pretty severely, if not base-64 encoded. It may be useful in some contexts to also provide an option for encrypting such data, though I'm not sure what implementation would be best.
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supercat9 wrote: Hmm.... I wonder whether it would be worthwhile to have a SQL library support a connect-string option for whether to report detailed data in its error messages
Yeah, something like that could work for SQL. SQL would probably not know if the connection is in debug mode so something like that would be required (or something like SET DEBUG_MESSAGE_DETAIL ON;), but for the .Net Framework there should be something like if (DEBUG) throw new ExceptionWithDetail(); else throw new Exception();, not sure if that will add significant code overhead though, or if we can get a SDK version of the framework that throws with detail but a "run time" version that throws without... (Or maybe inside the exception class collect info or not based on the DEBUG status)
supercat9 wrote: Key values would have a high likelihood of holding confidential data
Not sure if I agree with you fully on that but that is a matter of design, and can in some cases contain confidential data. I prefer to use and IDENTITY column or a GUID for keys (PRIMARY or FOREIGN), but Business Keys like Credit Card number will be confidential, so yeah, its not a simple thing to do but will have huge benefits for us coders and debuggers...
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Be brave little warrior, be VERY brave
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Adriaan Davel wrote: but for the .Net Framework there should be something like if (DEBUG) throw new ExceptionWithDetail(); else throw new Exception();
For best results, I think the server would have to know about the exception detail, since the server is responsible for generating the message. On the other hand, it might be possible to put a wrapper around the SQL object that would log its state (command string, parameters, etc.) immediately before the query, catch any exceptions, and wrap the exceptions in a package including the pre-query state. That wouldn't be as helpful as having the server adding the detail (since it wouldn't necessarily say which part of a multi-part query failed) but it might help somewhat.
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mmmm, interesting idea, think I'll do that right now in our solution... Not bad for a second prize 
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Be brave little warrior, be VERY brave
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There seems to be hope! I have just gotten a System.ArgumentNullException in a LINQ call and the message is: Value cannot be null.
Parameter name: source Great! Now to fix it!
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Be brave little warrior, be VERY brave
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Hi,
I'm working on generating dynamically an assembly to let a user customize things. To do that, I used CSharpCodeProvider to generate the assembly and that worked fine till I encountered the problem of recognizing an instance created with the first version of the assembly after getting a second version.
So here are the steps I followed:
1- I generated an assembly containing a class called "Class_1" which just has an attribute called "Name".
2- I created instance of that and added it to a set.
For now, I can display all the item of the set (I used a main class Root which is created not dynamically and from which all the dynamic classes will inherit from).
3- I regenerated the assembly after adding "Class_2" which inherits from Root too and have a method that get as parameter a "Class_1" instance and that displays the name of the instance.
4- I created an instance of the second class and called its method with the "Class_1" instance that I created before. Doing that raised the following exception:
Object of type 'TestProject_CustomClassesLibrary.Class_1' cannot be converted to type 'TestProject_CustomClassesLibrary.Class_1'.
I searched on the net about that and I found multiple things:
* Signing the assembly the GAC but when I tried it, nothing changed.
* Using domain application but this require stopping the application each time we want to generate I guess (did not tried it by the way). So that's not a solution for me.
Is there any solution for that? What should I do to make this work?
Thanks for all.
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Hi Guys,
I am running a command line application from inside my C# code, however it's failing and exiting out immediately. I'm trying to get the window to stay open after the program has finished running.
I've tried the following:
This opens the window, runs the script, fails and closes it:
Process.Start(@"C:\Program Files\Inno Setup 5\iscc.exe", @"%dir%\MyInstallScript.iss");
This opens the window, keeps it open, and says: 'C:\Program' is not recognized as an internal or external command, operable program or batch file.:
Process.Start("cmd.exe", "/k \"C:\\Program Files\\Inno Setup 5\\iscc.exe\" \"%dir%\\MyInstallScript.iss\"");
Second one seems a bit weird, as i am wrapping everything in quotes as expected. Not sure what's going on here. Do i need to do something crazy like nesting the quotes? And if so, how would i do that? Any thoughts?
Regards
Tris
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Carrier Bags - 21st Century Tumbleweed.
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Hi,
This looks straightforward but like you I cannot get it to work. I read the MSDN page on cmd.exe and the section on processing quotation marks left me completely baffled.
http://technet.microsoft.com/en-us/library/bb490880.aspx[^]
As with much of the stuff on MSDN it is missing a decent example. Can you understand what the /s switch does? May be I'm just thick but I don't think "Modifies the treatment of string after /c or /k" is an explanation.
A simple solution or workaround for your problem would be to start a batch file, e.g.
Process.Start("setup.cmd", "\"%dir%\\MyInstallScript.iss\"");
where setup.cmd is
@echo off
C:\Program Files\Inno Setup 5\iscc.exe "%~1"
pause
If you are concerned that the batch file could be modified by the user you could always have your program generate it just before it is required.
Alan.
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The entire command line after /k needs to be in quotes like so:
Process.Start("cmd.exe", "/k \"\"C:\\Program Files\\Inno Setup 5\\iscc.exe\" \"%dir%\\MyInstallScript.iss\"\"");
Note the extra quote characters at the start and the end of the argument after /k.
Eagles my fly, but weasels don't get sucked into jet engines.
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Oh I get it,
I would never have thought of trying out that many quotes although after unescaping everything it is clear that there is now only one string after the /k.
cmd.exe /k ""C:\Program Files\Inno Setup 5\iscc.exe" "%dir%\MyInstallScript.iss""
Alan.
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Ah. Thank you.
It's infuriating, i feel i was so close on my own! ^^
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Carrier Bags - 21st Century Tumbleweed.
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how to autoposition controls like label,hyperlink etc in visual studio 2008.I am able to enable the autopositioning options for textbox,button etc
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Docking won't work for labels, until you set AutoSize to "False".
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I want to create a windows form in c#.net and i want contents to be viewed in different blocks.But which is the control used to add partition???I saw panel control,but i want the partition line to be visible
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Use Splitter control.
Be an Eagle, Sky is Yours.
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can you tell how the same can be done in a webform?
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