Many-to-Many control and Master detail

Question

Hello,

I am trying to use the many-to-many control in a screen that displays a master with 2 levels of details. lets say Master/Detail1/Detail2.

The many-to-many control is bound to a navigation property of the second level detail : Detail2.

When the screen displays an existing entity every thing goes fine, but when the screen is used to create a new entity, it raises an exception (without stopping in the code) that says that there is a binding exception with bad argument conversion.

NB: I have used this sample to create my screen for both editing and showing an entity: http://msdn.microsoft.com/en-us/lightswitch/ff945359

Thanks for your help.

Answer 1

Hi

Can you give us a capture for explain what you really want?

From you description, I think after you add a new entity, you need to save it and refresh the program, otherwise the data will not save in your data base.

Hope it helpful.

Answer 2

Hi,

I finally found what was my problem, and it have no concern with the many-to-many control ! so I apologize for posting it in the wrong section.

In fact, the problem is that the 9th tutorial on LS developer center (http://msdn.microsoft.com/en-us/lightswitch/ff945359) is not working correctly with VS11: having an auto-opened query requiring a parameter (in my case an int) tha is null craches with no possbility of debug at all.

The solution was to use a non persistent query in the code. (when creating a new Master)

Regards.