ScriptMethodAttribute Class

This attribute is used to specify information for methods that can be called from client script. The attribute lets you specify which HTTP verb (GET or POST) can be used to invoke a method. It also lets you specify whether the response is formatted by using either JavaScript Object Notation (JSON) or XML.

The ScriptMethodAttribute attribute is optional. (However, methods that can be called from client script must have the System.Web.Services.WebMethodAttribute attribute applied.). If a method is not marked with ScriptMethodAttribute, the method will be called by using the HTTP POST command and the response will be serialized as JSON. You cannot override this setting from script.

ScriptMethodAttribute takes only named parameters. The following are the properties of the ScriptMethodAttribute class that can be used as named parameters:

• UseHttpGet

  Specifies whether the method will be invoked by using the HTTP GET command. The default is false.

  Security Note
  Setting the UseHttpGet property to true might pose a security risk for your application if you are working with sensitive data or transactions. In GET requests, the message is encoded by the browser into the URL and is therefore an easier target for tampering. For both GET and POST requests, you should follow security guidelines to protect sensitive data.

• ResponseFormat

  Specifies whether the response will be serialized as JSON or as XML. The default is Json. The ResponseFormat property is useful to specify XML as the return type when the method returns an XmlDocument or an XmlElement object.

• XmlSerializeString

  Specifies whether all return types, including string types, are serialized as XML. The value of the XmlSerializeString property is ignored when the response is serialized as JSON.

For more information about how to use attributes, see Extending Metadata Using Attributes.

The following example shows how to apply ScriptMethodAttribute to the GetXmlDocument and EchoStringAndDate methods to specify which HTTP verb to use and to specify the response format.

<%@ WebService Language="C#" Class="System.Web.Script.Services.CS.WebService" %>

using System;
using System.Web;
using System.Web.Services;
using System.Xml;
using System.Web.Services.Protocols;
using System.Web.Script.Services;

namespace System.Web.Script.Services.CS
{
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    [ScriptService]
    public class WebService : System.Web.Services.WebService
    {

        private string _xmlString =
            @"<?xml version=""1.0"" encoding=""utf-8"" ?>
                <message>
                    <content>
                        Welcome to the asynchronous communication layer world!
                    </content>
                </message>";

        // This method returns an XmlDocument type.
        [WebMethod]
        [ScriptMethod(ResponseFormat = ResponseFormat.Xml)]
        public XmlDocument GetXmlDocument()
        {
            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.LoadXml(_xmlString);
            return xmlDoc;
        }

        // This method uses GET instead of POST.
        // For this reason its input parameters
        // are sent by the client in the
        // URL query string.
        [WebMethod]
        [ScriptMethod(UseHttpGet = true)]
        public string EchoStringAndDate(DateTime dt, string s)
        {
            return s + ":" + dt.ToString();
        }

        [WebMethod]
        public string GetServerTime()
        {

            string serverTime =
                String.Format("The current time is {0}.", DateTime.Now);

            return serverTime;

        }

        [WebMethod]
        public string Add(int a, int b)
        {

            int addition = a + b;
            string result = 
                String.Format("The addition result is {0}.", 
                    addition.ToString());

            return result;

        }

        [WebMethod]
        [ScriptMethod(ResponseFormat = ResponseFormat.Xml, 
            XmlSerializeString = true)]
        public string GetString()
        {
            return "Hello World";           
        }

    }

}

.NET Framework

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

Other Resources