Hi Guys,
I'm creating a WPF application, allowing a user to enter in details using CRUD operation using Entity Framework (also using a Repository pattern).
So far, I've created an Application that allows a user to enter a 'Prospect' client. I am able to edit this 'Prospect, add a new one and able to delete with ease.
This 'Prospect' though has a Foreign Key relation within another table known as 'ProspectMeeting', taking the ProspectID from the 'Prospect' table.
When I 'Select' a 'Prospect' from the ListView though, it doesn't show the data of that selected 'Prospect'. Further more, when I select a 'Prospect' from the ListView, the command should be enabled for me to add a 'ProspectMeeting' but when I do add, it
crashes and produces this error;
Unable to cast object of type '*ProspectListViewModel' to type '*.ProspectViewModel'.
This is the code that it throws the error at (this is in the ProspectMeetingView);
private void btnAddMeeting_Click(object sender, RoutedEventArgs e)
{
ProspectMeetingView view = new ProspectMeetingView();
ProspectMeetingViewModel meeting = new ProspectMeetingViewModel();
//Throws the error on this line here//
meeting.Prospect = (ProspectViewModel)this.DataContext;
meeting.Mode = Mode.Add;
view.DataContext = meeting;
view.ShowDialog();
}
The Image below is the image of what I want to achieve - So hope that gives a better understanding of what I want to achieve.
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In my repository I use this to get a List of 'ProspectMeetings' using the ProspectID;
public List<ProspectMeeting> GetMeetingByProspect(int _ProspectID)
{
using (var context = new DBEntities())
{
return context.Prospects.First(i => i.ProspectID == _ProspectID).ProspectMeetings.ToList();
}
}In my ProspectViewModel, I use this Observable Collection to get the data from the 'ProspectMeetingViewModel;
private ObservableCollection<ProspectMeetingViewModel> prospectMeetings = null;
public ObservableCollection<ProspectMeetingViewModel> ProspectMeetings
{
get { return GetProspectMeetings(); }
set
{
prospectMeetings = value;
OnPropertyChanged("ProspectMeetings");
}
}
internal ObservableCollection<ProspectMeetingViewModel> GetProspectMeetings()
{
ProspectMeetingRepository c = new ProspectMeetingRepository();
prospectMeetings = new ObservableCollection<ProspectMeetingViewModel>();
prospectMeetings.Clear();
foreach (DataObjects.ProspectMeeting i in c.GetMeetingByProspect(this.ProspectID))
{
ProspectMeetingViewModel prospectMeeting = new ProspectMeetingViewModel(i);
prospectMeeting.Prospect = this;
prospectMeetings.Add(prospectMeeting);
}
return prospectMeetings;
}And in my ProspectListViewModel;
private ProspectListViewModel() : base("")
{
this.ProspectList = GetProspects();
}
private ProspectViewModel selectedProspect = null;
public ProspectViewModel SelectedProspect
{
get
{
return selectedProspect;
}
set
{
selectedProspect = value;
OnPropertyChanged("SelectedProspect");
}
}
private ObservableCollection<ProspectViewModel> prospectList = null;
public ObservableCollection<ProspectViewModel> ProspectList
{
get
{
return GetProspects();
}
set
{
prospectList = value;
OnPropertyChanged("ProspectList");
}
}
internal ObservableCollection<ProspectViewModel> GetProspects()
{
if (prospectList == null)
prospectList = new ObservableCollection<ProspectViewModel>();
prospectList.Clear();
foreach (DataObjects.Prospect i in new ProspectRepository().GetAll())
{
ProspectViewModel c = new ProspectViewModel(i);
prospectList.Add(c);
}
return prospectList;
}
I've been following this
link to help me but I've become unstuck. Personally, When i look through my code, I think that it has something to do with the Repository not getting the data. But I am not too sure.
I hope some one could advice or me or help me with this issue. If more code needs to be added then just let me know, I only added the data that I thought was appropriate.
Many thanks,
Greg.