Question

I was wondering if there was an addon that could detect and create a warning (or error) if it detects the creation of an IDisposable object that is never disposed.

I looked through Resharper’s docs but didn’t see anything that looked like what I was wanting.

edit – To be more specific, I should have said a Local variable that implements IDisposable, but is never Disposed.

For instance, a Pen is created in a paint method, but not disposed with after the drawing is done.

Answer 1

This has been turned on and off a few times in FxCop. Its current state is on again, at least for the version that comes with VS2010. It generates CA2000 on this code:

    protected override void OnPaint(PaintEventArgs e) {
        var pen = new Pen(Brushes.Black);
    }

Warning 5 CA2000 :
Microsoft.Reliability : In method
‘Form1.OnPaint(PaintEventArgs)’, call
System.IDisposable.Dispose on object
‘pen’ before all references to it are
out of scope.

Beware that the reliability of this warning isn’t great, it is a difficult problem to solve.