Question

I am doing a little debugging, and so I want to log the eventArgs value

I have a simple line that basically does:

logLine = 'e.Value: ' + IIf(e.Value Is Nothing, '', e.Value.ToString()) 

The way I understand the IIF function, if the e.Value is Nothing (null) then it should return the empty string, if not it should return the .ToString of the value. I am, however getting a NullReferenceException. This doesn’t make sense to me.

Any idea’s?

Answer 1

IIf is an actual function, so all arguments get evaluated. The If keyword was added to VB.NET 2008 to provide the short-circuit functionality you’re expecting.

Try

logLine = 'e.Value: ' + If(e.Value Is Nothing, '', e.Value.ToString())