查找在ASP.NET中使用某个接口的控件

public interface IMyControl
{
    void DoSomething();
    string GetText();
}

public class MyControl : System.Web.UI.Control, IMyControl
{
    public void DoSomething()
    {
        // 实现DoSomething方法
    }

    public string GetText()
    {
        // 实现GetText方法
    }
}

<%@ Register TagPrefix="my" Namespace="MyNamespace" Assembly="MyAssembly" %>

<my:MyControl ID="myControl" runat="server" />

IMyControl myControl = (IMyControl)FindControl("myControl");
myControl.DoSomething();
string text = myControl.GetText();