Question

I have 2 partial classes, Window A(frmSchedule) and Window B(frmAddLesson). Window A has a data-bound ListView control in it. Window A opens up Window B, which is designed to create a new Lesson object, and I want to put that lesson data back into Window A. What are some of the ways I can accomplish this? Is there an easy way to use application-scope variables in C#?

I’ve tried deriving both partial classes from a single base class and using that class to funnel the Lesson data back to the 1st window, but I can’t figure it out. 🙁

For more info, I’ve laid out the program here:

I have a main window(fmrSchedule) with a ListView control bound to an ObservableCollection:
(For the sake of simplicity, I’ll pretend the Lesson object has only 1 piece of data that matters)

    <ListView Name="lstLessons" Margin="204,15,192,125" ItemsSource="{Binding Path=LessonList}">
        <ListView.View>
            <GridView>
                <GridViewColumn DisplayMemberBinding="{Binding Time}">Time</GridViewColumn>
            </GridView>
        </ListView.View>
    </ListView>

In the code:

public partial class frmSchedule : Window
{        
    public frmSchedule()
    {
        InitializeComponent();

        //ListView sample data
        aLesson = new Lesson();
        aLesson.Time = 9;
        m_myLessons.Add(aLesson);
        lstLessons.ItemsSource = LessonList;
    }

    Lesson aLesson;

    private ObservableCollection<Lesson> m_myLessons = new ObservableCollection<Lesson>();
    public ObservableCollection<Lesson> LessonList { get { return m_myLessons; } }

    //Add Lesson
    private void btnAdd_Click(object sender, RoutedEventArgs e)
    {
        //New frmAddLesson window
        frmAddLesson addLesson = new frmAddLesson();
        addLesson.Show();
    }

The btnAdd button control opens a 2nd form(frmAddLesson), which serves to create a new Lesson object to be added to the Lesson list in the main window: (in this case, time is set based on a combobox selection)

public partial class frmAddLesson : Window
{
    public frmAddLesson(System.DateTime? DateTime)
    {
        InitializeComponent();

        dateTime = DateTime;
        radPrivate.IsChecked = true;
    }

    //DateTime from calendar selection
    private DateTime? dateTime;
    //Lesson object
    private Lesson theLesson;

    //ADD LESSON
    private void btnAdd_Click(object sender, RoutedEventArgs e)
    {
        //Create new Lesson object
        theLesson = new Lesson();

        //Set Lesson property
        theLesson.Time = (int)cmbTime.SelectedValue; //Time

        this.Close();
    }
}

The Lesson class:

public class Lesson
{
    public Lesson()
    {
        //Stuff for later
    }

    private int m_Time;

    public int Time { get { return m_Time; } set { m_Time = value; } }
}

Answer 1

public partial class frmSchedule : Window 
{       
   ...  
   private void btnAdd_Click(object sender, RoutedEventArgs e)  
   {  
    //New frmAddLesson window  
    frmAddLesson addLesson = new frmAddLesson(this);  
    addLesson.Show();  
   }  

   public void AddLesson(Lesson lesson)
   {
     ...
   }
}

public partial class frmAddLesson : Window    
{
  public frmAddLesson(frmSchedule schedule)      
  {      
    InitializeComponent();      

    this.schedule = schedule;

    ...

  }    
  frmSchedule schedule;

  //ADD LESSON    
  private void btnAdd_Click(object sender, RoutedEventArgs e)    
  {    
    //Create new Lesson object    
    var theLesson = new Lesson();    

    //Set Lesson property    
    theLesson.Time = (int)cmbTime.SelectedValue; //Time    

    schedule.AddLesson(theLesson);

    this.Close();    
  }    
}