Grid that represents a collection of a base class

[Alexis Bilodeau]

Hi,

I have the following business objects:

Contact
|
|--- Person
|
|--- Department

I have bound my GridDataControl to a collection of Contacts (through a CollectionView). However, the grid fails when there are both Persons and Departments in the collection.

Let's say I have a Person in the collection. When I add a Department to the underlying collection, the method OnListSourceListChanged (defined in Syncfusion.Linq.Base) throw an InvalidCaseException because it tries to cast the newly added Department into a Person.

Is there a way to force the grid to use the base class instead?

Obviously I display only properties that are defined in the base class.

Any ideas?

Thanks,

Alex

[Jeraldes J]

Hi Alexis,

Regarding this i have created a sample and have implemented in the grid. Please download the sample from the below link.

http://www.syncfusion.com/uploads/redirect.aspx?file=GDC-Instance Grouping-95662_354a98cb.zip&team=development

Still if you have the issue please modify the sample and we will update on behalf of that.

Let us know if you need any other details.

Regards,
Jeraldes J

[Alexis Bilodeau]

Hi,

This isn't exactly what I want. I have made a sample to show exactly what I am trying to do.

In this sample, the business objects are Users, Tasks, Errands and Meetings.

A User is linked to a collection of Tasks through a navigation property defined in the Entity Framework model, thus a Task is linked to a User.

A task can be an Errand or a Meeting, both inherit from the Task class.

The grid shows the tasks for a given User, then you can add either an Errand or a Meeting for this User.

To reproduce the error, you simply have to add an Errand, then a Meeting (or vice versa) for the pre-selected User.

Please let me know if you need any more information since this use case is very important for us and appears in several places within our applications.

Thank you very much,

Alex



Base Class Collection Demo_7226f981.zip

[Alexis Bilodeau]

Hi Jeraldes,

Do you have an update on this?

Thank you,

Alex

[Jeraldes J]

Hi Alexis,

We have referred with your sample regarding your issue. Since you are using the entity collection model, the object that is posted initially will be directly set to the collection property. When you try to insert another object it will not be accepted by the entity collection. This issue is due to the declaration problem in the entity collection not in binding the grid. So please refer with the entity collection operation.

Let us know if you face any other issues.

Regards,
Jeraldes J

[Alexis Bilodeau]

Hi,

I have to disagree for two reasons. The first one is that the demo program works just fine if you remove the ItemsSource property from the grid definition (of course nothing displays in the grid, but you can see in debug that the Errands and the Meetings are added to the Entity model).

Second reason is that the exception comes from one of your classes as seen below from the Stack trace:

{"Unable to cast object of type 'Base_Class_Collection_Demo.Meeting' to type 'Base_Class_Collection_Demo.Errand'."}

at Syncfusion.Windows.Data.SourceListWrapper`1.OnListSourceListChanged(Object sender, ListChangedEventArgs e)
at System.ComponentModel.ListChangedEventHandler.Invoke(Object sender, ListChangedEventArgs e)
at
...

Thank you,

Alex

[Jeraldes J]

Hi Alexis,

For your future reference please follow the incidence id #70851.

We will update you through that incident.

Let us know if you need any other details.

Regards,
Jeraldes J