设定控件获得焦点

今天看到AJAX ControlToolKit的源码中得到一个类,代码如下:

using System;
using System.Web.UI;

namespace AjaxControlToolkit
{
    public static class Utility
    {
        public static void SetFocusOnLoad(Control control)
        {
            if (control == null)
            {
                throw new ArgumentNullException("control", "Control cannot be null!");
            }

            string script =
                "(function() {\n" +
                    "var fn = function() {\n" +
                        "var control = $get('" + control.ClientID + "');\n" +
                        "if (control && control.focus) { control.focus(); }\n" +
                        "Sys.Application.remove_load(fn);\n" +
                    "};\n" +
                    "Sys.Application.add_load(fn);\n" +
                "})();\n";
            ScriptManager.RegisterStartupScript(control.Page, control.GetType(),
                control.ClientID + "_SetFocusOnLoad", script, true);
        }
    }
}

我觉得用这个代码设定焦点很不错.
有关Sys.Application的用法可以参考AJAX的客户端参考!