Chap 10, error creating new projects

Moose · December 16th, 2011, 02:22 PM

When you attempt the task on page 299 to add a new project using the downloaded code for the examples in Chap 10 (and the ones in Chap 11 as well) the app throws a "Null Object Reference error".

The culprits are the two functions in ListProjects.cs - "CloseProject_CanExecute()" and "ReopenProject_CanExecute()".

I simply commented these two out and the app worked fine for the example in chap 10.

Why were these functions added? How do you fix them?

Thanks

simpiligno · February 16th, 2012, 08:03 PM

This is because no project is selected. If you wrap the result in a statement to check and see if a project is selected, it will work properly.

VB Example:

Code:

If Projects.SelectedItem IsNot Nothing Then
     result = Me.Projects.SelectedItem.Closed
End If

Note: You must save the new project and click refresh to be able to view the additional cost for the newly created project.