DataGridView DataGridViewCheckBoxCell throws NullReferenceException

[Karen Hill]

I have a datagridview control on a form with a few of the columns being
DataGridViewCheckBox. Whenever I click on the checkbox to create a new
record I get a NullReference Exception thrown even though I check for
NULL using System.Convert.IsDbNull function.

What gives?

I'm catching the NullReferenceException, although I know it is not
correct to do for normal program flow. What is the solution?

 

[Gino]

Without seeing some code I can only generalize.

NullRefference errors indicate that a method or property is being accessed
without its class being instantiated.



DBnull errors indicate that a Null is being returned from the DataBase and
its type is not recognized by the compiler.

In that case you can look into overriding, and handle it inside.

 

[Rick Shaw]

How about setting the threestate property if the checkbox to true. This
will allow the checkbox to accept anything other than true or false.

Try that out.

Rick..