Question

Still new to LINQ2SQL so please forgive my ignorance …

I have one user component which includes one Textbox and one button. The component is used as a generic ListOfValue Filter.
The component has one function to set a IQueryable which is passed to a form that is opened when the user clicks a button on the control.
The form consists of a grid (c1flexgrid) which is filled with the data from the IQueryable. There is a bindingsource on the form that gets the IQueryable as datasource.
The user can select inside the grid and after he selected an entry the dialog is closed and the selected row (or better the selected LINQ2SQL object from the row) is passed back to the control.
On this control i want to show one specific field out of that selected object. The name of that field is passed in to the user control as string.

My problem is, i don’t know how to get that field data from an “generic” LINQ2SQL object.
In debugger i can see, that the selected object is of a specific enity type (corresponding to the query)

Probably somthing similar to
Workaround for lack of 'nameof' operator in C# for type-safe databinding?
but just the opposit way 🙂

Any help would be very welcome

Answer 1

I’m assuming in your IQueryable you don’t know at design time the type T. If this is correct, you need to use reflection to get the value you want.

var value = typeof(T).GetProperty("MyField").GetValue(instance, null);

Alternatively, cast the instance to a common base type that implements your field.

CommonBase castInstance = (CommonBase)instance;
var value = castInstance.MyField;