ShellViewModel处理eventAggregator Caliburn.Micro上的多个消息

Question

I am building an application to help me learn C#, WPF and .NET. In my application, I am loading multiple CVS sheets of accounting data for repair orders, each CVS represents a different schedule. This is working great using eventAggregator. When the user presses the "load Schedule" button another window opens that has a drop down box to select the schedule name, and a button that opens a "OpenFileDialoge" box. After the user selects both clicking "Load" trigers "_eventAggregator.PublishOnUIThread(SchedInfo);". The ShellViewModel has a HAndle that takes the Published "SchedInfo" and passes the data to another function that reads the file -> builds each RepairOrder and adds them to a BindableCollection of Repair Orders that is bound to a datagrid. This is working amazingly. My issue now is that I want to create a second system that works the same but reads an excel file and creates the repair orders from this. I created a second ViewModel, view, and class for the excel message to be sent across the eventAggregator. I also created a completely new "Handle(Message Class)" to work with the new message type. However my new version does not seem to be passing the data back to the "ShellViewModel" or the "ShellViewModel" is not accepting the data. Can someone please see where I went wrong.

This is the ViewModel code for the working window:

namespace ScheduleReview.ViewModels
{
    class SelSchedViewModel : Screen
    {
        /* System level properties */
        private readonly IEventAggregator _eventAggregator;
        List<string> folder = new List<string>();


        /* Class level properties*/

        private BindableCollection<string> _cmboBoxOptions = new BindableCollection<string>() { "Navistar", "Cummins", "Misc", "Kenworth", "Mack/Volvo" };

        public BindableCollection<string> CmboBoxOption
        {
            get { return _cmboBoxOptions; }
            set {
                _cmboBoxOptions = value;
                NotifyOfPropertyChange(() => CmboBoxOption);
            }
        }

        private string _scheduleName;

        public string ScheduleName
        {
            get { return _scheduleName; }
            set {
                _scheduleName = value;
                NotifyOfPropertyChange(() => ScheduleName);
            }
        }

        private string _fileLocation;

        public string FileLocation
        {
            get { return _fileLocation; }
            set {
                _fileLocation = value;
                NotifyOfPropertyChange(() => FileLocation);

            }
        }

        private string _fullLocation;

        public string FullLocation
        {
            get { return _fullLocation; }
            set {
                _fullLocation = value;
                NotifyOfPropertyChange(() => FullLocation);
            }
        }


        /* Constructor */
        public SelSchedViewModel(IEventAggregator eventAggregator)
        {
            this._eventAggregator = eventAggregator;
        }

        //Needs work still
        public void LoadSchedule()
        {
            if (folder.Contains(FileLocation))
            {
                MessageBox.Show("This file has already been used ", "Loaded File", MessageBoxButton.OK, MessageBoxImage.Error);
                ScheduleName = null;
                FileLocation = null;
                return;
            }

            //Create and set the class to return from
            //string file location and schedule number
            if(ScheduleName == null || FileLocation == null)
                {
                    MessageBox.Show("Enter the schedule name and choose a file location!", "Invalid Selections", MessageBoxButton.OK,MessageBoxImage.Error);
                }
                else
                {
                    ScheduleInfo SchedInfo = new ScheduleInfo(ScheduleName, FullLocation);
                    _eventAggregator.PublishOnUIThread(SchedInfo);
                    folder.Add(FileLocation);

                    ScheduleName = null;
                    FileLocation = null;

                }
            }

        public void SelectFile()
        {

            //Open the file selector box
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.InitialDirectory = Environment.SpecialFolder.MyDocuments.ToString();
            ofd.DefaultExt = ".csv";
            ofd.Filter = "CSV Documents (.CSV)|*.csv";

            Nullable<bool> result = ofd.ShowDialog();
            if (result == true)
            {
                FullLocation = ofd.FileName;
                char delimiter = '\\';
                string[] NameArray = ofd.FileName.Split(delimiter);
                FileLocation = NameArray[NameArray.Count() - 1];
            }
        }

        //Closes Window
        public void Close()
        {
            TryClose();
        }
    }
}

This is the Handle in ShellViewModel that is working:

public void Handle(ScheduleInfo message)
        {
            ScheduleName = message.ScheduleName;
            FileInfo = message.FileLocation;
            LoadSchedule(ScheduleName, FileInfo);
        }

Here is the code for the POCO class that is passed from the working loader to the ShellViewModel:

namespace ScheduleReview.Models
{
    public class ScheduleInfo
    {
        public string ScheduleName
        {
            get;
            private set;
        }

        public string FileLocation
        {
            get;
            private set;
        }

        public ScheduleInfo(string SN, string FL)
        {
            ScheduleName = SN;
            FileLocation = FL;
        }
    }
}

Now I actually copy and pasted the window design and most of the ViewModel from the first ViewModel that pops up. Created and new message class for the new Loader window and changed the Sections in the new window to match the new message class.

The code for the ViewModel of the new Loader is:

namespace ScheduleReview.ViewModels
{
    class SelCDKSchedViewModel : Screen
    {
        /* System level properties */
        private readonly IEventAggregator _eventAggregator;
        List<string> folder = new List<string>();


        /* Class level properties*/

        private BindableCollection<string> _cmboBoxOptions = new BindableCollection<string>() { "Navistar", "Cummins", "Misc", "Kenworth", "Mack/Volvo" };

        public BindableCollection<string> CmboBoxOption
        {
            get { return _cmboBoxOptions; }
            set
            {
                _cmboBoxOptions = value;
                NotifyOfPropertyChange(() => CmboBoxOption);
            }
        }

        private string _scheduleName;

        public string ScheduleName
        {
            get { return _scheduleName; }
            set
            {
                _scheduleName = value;
                NotifyOfPropertyChange(() => ScheduleName);
            }
        }

        private string _fileLocation;

        public string FileLocation
        {
            get { return _fileLocation; }
            set
            {
                _fileLocation = value;
                NotifyOfPropertyChange(() => FileLocation);

            }
        }

        private string _fullLocation;

        public string FullLocation
        {
            get { return _fullLocation; }
            set
            {
                _fullLocation = value;
                NotifyOfPropertyChange(() => FullLocation);
            }
        }


        /* Constructor */
        public SelCDKSchedViewModel(IEventAggregator eventAggregator)
        {
            this._eventAggregator = eventAggregator;
        }

        //Needs work still
        public void LoadSchedule()
        {
            if (folder.Contains(FileLocation))
            {
                MessageBox.Show("This file has already been used ", "Loaded File", MessageBoxButton.OK, MessageBoxImage.Error);
                ScheduleName = null;
                FileLocation = null;
                return;
            }

            //Create and set the class to return from
            //string file location and schedule number
            if (ScheduleName == null || FileLocation == null)
            {
                MessageBox.Show("Enter the schedule name and choose a file location!", "Invalid Selections", MessageBoxButton.OK, MessageBoxImage.Error);
            }
            else
            {
                CDKScheduleInfo CDKSchedInfo = new CDKScheduleInfo(ScheduleName, FullLocation);
                _eventAggregator.PublishOnUIThread(CDKSchedInfo);
                folder.Add(FileLocation);

                ScheduleName = null;
                FileLocation = null;

            }
        }

        public void SelectFile()
        {

            //Open the file selector box
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.InitialDirectory = Environment.SpecialFolder.MyDocuments.ToString();
            ofd.DefaultExt = ".xlsx";
            ofd.Filter = "XLSX Documents (.XLSX)|*.xlsx";

            Nullable<bool> result = ofd.ShowDialog();
            if (result == true)
            {
                FullLocation = ofd.FileName;
                char delimiter = '\\';
                string[] NameArray = ofd.FileName.Split(delimiter);
                FileLocation = NameArray[NameArray.Count() - 1];
            }
        }

        //Closes Window
        public void Close()
        {
            TryClose();
        }
    }
}

Code for the Handle of the new Loader window:

public void Handle(CDKScheduleInfo message)
        {
            ScheduleName = message.ScheduleName;
            FileInfo = message.FileLocation;
            ReadFromCDKExport(ScheduleName, FileInfo);
        }

Poco class for the NOT working loading window.

class CDKScheduleInfo
    {
        public string ScheduleName
        {
            get;
            private set;
        }

        public string FileLocation
        {
            get;
            private set;
        }

        public CDKScheduleInfo(string SN, string FL)
        {
            ScheduleName = SN;
            FileLocation = FL;
        }

    }

From what I read Caliburn.Micro's implementation of the eventAggregator allows the "Handles" to use polymorphism, so I felt the two handles accepting different Class objects as I have them should work.

As a test I commented out the line in the NOT working handle "ReadFromCDKExport(ScheduleName, FileInfo);" so the public variables "ScheduleName" and "FileInfo" would just get set, then I wired a test button to show:

MessageBox.Show(ScheduleName + Environment.newline + FileInfo, "Test", MessageBoxButton.OK);

The message box would pop up but there was no variables in the message.

---------------------EDIT Based on Royi's Answer-----------------------------

I forgot to add the IHandle interface to the Class.

Answer 1

The eventAggregator uses the interface IHandle to figure out the polymorphism,

You probably forgot to add the IHandle for CDKScheduleInfo interface to ShellViewModel :)