On Save Event

Question

Hello everyone,
I'm relatively new to programming in C# and i have a program I have been writing that i have come across a snag.
Basically, my program is connected to a MS Access database with a required field.  In it's current state if you fill in most of the fields w/o filling in the required field and try to save it, it crashes the program.
Is there a way to tie in an on click event that would search for a null value, and pop up an error message informing the user to enter information is said field?  Im using Visual Studio 2008.
The save command im talking about is the disk icon that is on the database navigation toolbar that appears when you drag your first data bound object to the Windows form.
Thanks for all the help in advance!
Bradley from Chattanooga, TN.

Mike Gold · Answer

I think you need to provide more information as to the error, like a stack trace.  If you go into the Debug menu in Visual Studio and go to  Exceptions, Check the box marked catch CLR (Common Language Runtime) Exceptions, it will stop in the debugger at the exception and you'll be able to view the call stack to see what is happening as well as look at variables in the watch window or by hovering over them.

Bradley Lathan · Answer

Thanks Mike for giving me direction! Included is my complete source code for the onClick event.  It still crashes in debug mode.  Do you have any suggestions on what i can do to fix it?  Do I need to provide more information?
Source Code:
private void cUSTOMER_DATABindingNavigatorSaveItem_Click(object sender, EventArgs e)
{
try
{
this.Validate();
this.cUSTOMER_DATABindingSource.EndEdit();
this.tableAdapterManager.UpdateAll(this.cUSTOMERDATADataSet);
}
catch (NoNullAllowedException ex)
{
MessageBox.Show(ex.Message.ToString());
}
}
Thanks a Bunch.

Sam Hobbs · Answer

I would go to the place in the program that it is crashing and fix it so it give an error message or something other than crashes.
Other than that, I don't understand what you mean by "search for a null value".

Mike Gold · Answer

I would start by catching the Exception with try catch so the program doesn't crash.  Then popup a message box with the problem
try
{
// your code
}
catch (Exception ex)
{
MessageBox.Show(ex.Message.ToString());
}