getting NullReferenceException information

Hi,
When i get a NullReferenceException or "Object reference not set to an instance of an object." exception, how do i find out what object reference was not instantiated?

Thanks
LVL 1
3MannAsked:
Who is Participating?
 
AnnamalaiSwamyCommented:
Catch the NullReferenceException by try...catch block and get more information about uninstantiated object through "Source" property of NullReferenceException object.


e.g.,

try
{
  some error
}catch(NullReferenceException e)
{
    msg = e.source;   //gives more details
}
Thanks
0
 
TheAvengerCommented:
You should have a look at the StackTrace of the exception and thus find the line where the exception occured. Then debug the application by putting a break point on that line and when the application reaches the point, you can see the values of all variables used there - see which is null.
0
 
DaeljanCommented:
Also dont forget to unroll inner exceptions to get as much info as possible:

assuming 'e' is the System.Exception

// examine:       e.Message, e.StackTrace

System.Exception innerE = e.InnerException;
while (innerE != null)
{
    // examine:       e.Message, e.StackTrace
    innerE = innerE.InnerException;
}
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.