How to access ServerSide method from GridView's ItemTemplate

Calling a CodeBehind Method From GridView's ItemTemplate:


While working with GridView, there may be a case where 
we actually need to do some operations in serverside for 
which we may be in a need to call a server side
method from ItemTemplate of a GridView.


Say for example, 
I had a situation where i need to call a server side 
method (which return a string value) from ItemTemplate.
So i used a label in the ItemTemplate like 



<asp:TemplateField HeaderText="Testing">
<ItemTemplate>
<asp:Label ID="lblCustomerAge" Text='<%# GetCategory() %>' runat="server">
</asp:Label>
</ItemTemplate>
</asp:TemplateField>


Here GetCategory is the server side method.Code-behind is given below

  protected string GetCategory()
    {
       // Do whatever you want here
        return "TestCategory"; // For eg. passing a string
    }