NullReferenceException problem working with Dataset

[eljainc]

Hello,

I'm pretty new to C# programming, so be gentle with me. I have a block
of code which is the following:

scheduleDomainController1.ConnectionString = "data
source=.\\SQLEXPRESS;"+
"database=MyDatabase;Trusted_Connection=True;" ;
string AccountID = "00000000-0000-0000-0000-000000000000";

DataSet ds;
ds = new DataSet();
try
{
ds = scheduleDomainController1.GetScheduleDataSet(Accou ntID);
}
catch
{
MessageBox.Show("NullReferenceException in getting data');
}
The code that causes the NullReferenceException is:

ds = scheduleDomainController1.GetScheduleDataSet(Accou ntID);

scheduleDomainController is a component which allows one to connect
to a SQL database with minimal effort.

I am sure that the scheduleDomainController1 object has been created.
What else could cause this exception?

Thanks
Mike McWhinney

[Peter Bromberg [C# MVP]]

eljainc,
The code you present in your post is always going to show you a null
referenceException since you aren't even catching an instance of the
Exception object. Try revising it to something like this to get more valuable
info:
catch (Exception ex)
{
MessageBox.Show(ex.Message +ex.StackTrace);
}
-- Now you will be able to see what really happened, and where.
Peter
--
Co-founder, Eggheadcafe.com developer portal:
http://www.eggheadcafe.com
UnBlog:
http://petesbloggerama.blogspot.com


"eljainc" wrote:

Hello,

I'm pretty new to C# programming, so be gentle with me. I have a block
of code which is the following:

scheduleDomainController1.ConnectionString = "data
source=.\\SQLEXPRESS;"+
"database=MyDatabase;Trusted_Connection=True;" ;
string AccountID = "00000000-0000-0000-0000-000000000000";

DataSet ds;
ds = new DataSet();
try
{
ds = scheduleDomainController1.GetScheduleDataSet(Accou ntID);
}
catch
{
MessageBox.Show("NullReferenceException in getting data');
}
The code that causes the NullReferenceException is:

ds = scheduleDomainController1.GetScheduleDataSet(Accou ntID);

scheduleDomainController is a component which allows one to connect
to a SQL database with minimal effort.

I am sure that the scheduleDomainController1 object has been created.
What else could cause this exception?

Thanks
Mike McWhinney

[eljainc]

Thanks Peter for the programming correction.

However my code still reports an exception. It gives *more* detailed
information however (the offending line number). The exception
basically says, if I understand correctly, that that the object
dataSet1 has been created but not initialized with new(). It has been
created though. This is what stumps me.

Mike