How can I refresh a gridview in a custom control from the method of another

I am looking for a way to refresh one custom control inside a method of another. Here is what I have:


A.ascx <- contains (B,C) custom controls belowB.ascx <- adds data to SQL databaseC.ascx <- contains (D) custom control below
D.ascx <- shows data from SQL database

Data is added to SQL in the C# B.ascx code-behind method. Upon a new row being added I would like a GRIDVIEW inside the D.ascx control to refresh and show that new record immediately.
Initially I had all the code on the same page, but then needed to cut it into separate custom controls. The code worked perfectly fine before and now I need this refresh to happen again. The code I used before to refresh the gridview was like this:
//  sqlSummary.DataBind();
//  grdSummary.DataBind();



In the end I also need to up ...