Tutorial by Examples

try { /* code that could throw an exception */ } catch (Exception ex) { /* handle the exception */ } Note that handling all exceptions with the same code is often not the best approach. This is commonly used when any inner exception handling routines fail, as a last resort.

try { /* code to open a file */ } catch (System.IO.FileNotFoundException) { /* code to handle the file being not found */ } catch (System.IO.UnauthorizedAccessException) { /* code to handle not being allowed access to the file */ } catch (System.IO.IOException) { /* cod...

You are allowed to create and throw exceptions in your own code. Instantiating an exception is done the same way that any other C# object. Exception ex = new Exception(); // constructor with an overload that takes a message string Exception ex = new Exception("Error message"); Yo...

try { /* code that could throw an exception */ } catch (Exception) { /* handle the exception */ } finally { /* Code that will be executed, regardless if an exception was thrown / caught or not */ } The try / catch / finally block can be very handy when reading from files. ...

Implementing IErrorHandler for WCF services is a great way to centralize error handling and logging. The implementation shown here should catch any unhandled exception that is thrown as a result of a call to one of your WCF services. Also shown in this example is how to return a custom object, and h...

You are allowed to implement custom exceptions that can be thrown just like any other exception. This makes sense when you want to make your exceptions distinguishable from other errors during runtime. In this example we will create a custom exception for clear handling of problems the application ...

Swallowing Exceptions One should always re-throw exception in the following way: try { ... } catch (Exception ex) { ... throw; } Re-throwing an exception like below will obfuscate the original exception and will lose the original stack trace. One should never do this! The st...

Who says you cannot throw multiple exceptions in one method. If you are not used to playing around with AggregateExceptions you may be tempted to create your own data-structure to represent many things going wrong. There are of course were another data-structure that is not an exception would be mor...

One is able to nest one exception / try catch block inside the other. This way one can manage small blocks of code which are capable of working without disrupting your whole mechanism. try { //some code here try { //some thing which throws an exception. For Eg : divide by 0 ...

Cheatsheet DODON'TControl flow with control statementsControl flow with exceptionsKeep track of ignored (absorbed) exception by loggingIgnore exceptionRepeat exception by using throwRe-throw exception - throw new ArgumentNullException() or throw exThrow predefined system exceptionsThrow custom exce...

AppDomain.UnhandledException This event provides notification of uncaught exceptions.It allows the application to log information about the exception before the system default handler reports the exception to the user and terminates the application.If sufficient information about the state of the a...

Your code can, and often should, throw an exception when something unusual has happened. public void WalkInto(Destination destination) { if (destination.Name == "Mordor") { throw new InvalidOperationException("One does not simply walk into Mordor."); } ...