Question

I have a function that is called by several GUI components, and always needs to be run in a different Task.
Is there a difference between doing it in this way each time:

public int foo()
{
   // do what you need to do
   return 1;
}

...
var t = Task<int>.Factory.StartNew(() =>foo());

and starting the task inside the foo function?

public int foo()
{
   var t = Task<int>.Factory.StartNew(() =>
   {
       // do what you need to do
       return 1;
   });
}

...
foo();

I get System.AggregateException in this program, and I’m starting to think that the second way to start the task is a wrong one.

Answer 1

Have a look at the InnerException. The AggregateException is used to bundle up exceptions caused by Tasks/PLinq. More info here:

http://msdn.microsoft.com/en-us/library/system.aggregateexception.aspx

AggregateException is used to
consolidate multiple failures into a
single, throwable exception object. It
is used extensively in the Task
Parallel Library and Parallel LINQ
(PLINQ). For an example, see How to:
Handle Exceptions Thrown by Tasks and
How to: Handle Exceptions in a PLINQ
Query.

Worth also reading How to: Handle Exceptions Thrown by Tasks