Asp.Net LinkButton Onclick =方法（container.dataitem），需要语法帮助

I have a linkbutton that I want to call a method in the code behind. The method takes a parameter of which I need to stick in a container.dataitem. I know the container.dataitem syntax is correct because I use it in other controls. What I don't know is how to user it a parameter for a method. Upon clicking on the button, the method should be called with the container.dataitem. The method is called 'AddFriend(string username)' Below is code. Thank you!I have a linkbutton that I want to call a metho