How to Attach a separate file code into aspx page

I have a separate aspx Page called Home.aspx page and a separate class called class1.cs
I want to attach the class1 into Home.aspx
I try with this but not work
 
<%@ Page Language="C#" CodeFile="~/App_Code/Class1.aspx.cs" %>
I would be pleased if you help me.
Thank you.  
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