how to set ReaderId

hi
when i was using CheckboxSelectionModel it Gave me two fields :RecordID and RowIndex.but i think RecordId Is autogenerated and useless in serverside.is a solution for me to give my real Id(What is stored in databases) ?
What I found by searching was setting ReaderId in Reader object of Store but what is code for do it in mvc?
also i wrote this code but I see any change

Code:

---

        X.Store()
          .ID("myStore")
          .PageSize(10)
          .DataSource(Model)
          .Reader(X.JsonReader().IDProperty("Id") )

---

and value of RecordId Was like this: "ext-29-3"

Hello @TAYMA!

You need the IDProperty setting as you displayed in your code snippet, but somewhere else -- in the data model definition.

Take a look how it is used in this example: GridPanel > Data Presentation > Editor Field Mapping

Hope this helps!