mvc 返回 xml

 using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Text;
 using System.Web;
 using System.Web.Mvc;
 using System.Xml.Serialization;
 namespace PaiXie.Pos.Admin {
         /// <summary>
         /// 扩展System.Web.Mvc XmlRequestBehavior
         /// 指定是否允许来自客户端的HTTP GET请求
         ///</summary>
         public enum XmlRequestBehavior {
             /// <summary>
             /// HTTP GET requests from the client are allowed.
             /// 允许来自客户端的HTTP GET请求
             /// </summary>
             AllowGet = ,
             /// <summary>
             /// HTTP GET requests from the client are not allowed.
             /// 不允许来自客户端的HTTP GET请求
             /// </summary>
             DenyGet = ,
         }
         /// <summary>
         /// 实现XmlResult继承ActionResult
         /// 扩展MVC的ActionResult支持返回XML格式结果
         /// </summary>
         public class XmlResult : ActionResult {
             /// <summary>
             /// Initializes a new instance of the System.Web.Mvc.XmlResult class
             /// 初始化
             /// </summary>
             public XmlResult() { }
             /// <summary>
             /// Encoding
             /// 编码格式
             /// </summary>
             public Encoding ContentEncoding { get; set; }
             /// <summary>
             /// Gets or sets the type of the content.
             /// 获取或设置返回内容的类型
             /// </summary>
             public string ContentType { get; set; }
             /// <summary>
             /// Gets or sets the data
             /// 获取或设置内容
             /// </summary>
             public object Data { get; set; }
             /// <summary>
             /// Gets or sets a value that indicates whether HTTP GET requests from the client
             /// 获取或设置一个值,指示是否HTTP GET请求从客户端
             /// </summary>
             public XmlRequestBehavior XmlRequestBehavior { get; set; }
             /// <summary>
             /// Enables processing of the result of an action method by a custom type that
             /// 处理结果
             /// </summary>
             /// <param name="context"></param>
             public override void ExecuteResult(ControllerContext context) {
                 if (context == null) { throw new ArgumentNullException("context"); }
                 HttpRequestBase request = context.HttpContext.Request;
                 if (XmlRequestBehavior == XmlRequestBehavior.DenyGet && string.Equals(context.HttpContext.Request.HttpMethod, "GET", StringComparison.OrdinalIgnoreCase)) {
                     throw new InvalidOperationException("XmlRequest_GetNotAllowed");
                 }
                 HttpResponseBase response = context.HttpContext.Response;
                 response.ContentType = !string.IsNullOrEmpty(this.ContentType) ? this.ContentType : "application/xml";
                 if (this.ContentEncoding != null) {
                     response.ContentEncoding = this.ContentEncoding;
                 }
                 if (Data != null) {
                     using (MemoryStream ms = new MemoryStream()) {
                         XmlSerializer xs = new XmlSerializer(Data.GetType());
                         xs.Serialize(ms, Data); // 把数据序列化到内存流中
                         ms.Position = ;
                         using (StreamReader sr = new StreamReader(ms)) {
                             context.HttpContext.Response.Output.Write(sr.ReadToEnd()); // 输出流对象
                         }
                     }
                 }
             }
         }
         /// <summary>
         /// 扩展System.Mvc.Controller
         /// </summary>
         public static class ControllerExtension {
             public static XmlResult Xml(this Controller request, object obj) { return Xml(obj, null, null, XmlRequestBehavior.DenyGet); }
             public static XmlResult Xml(this Controller request, object obj, XmlRequestBehavior behavior) { return Xml(obj, null, null, behavior); }
             public static XmlResult Xml(this Controller request, object obj, Encoding contentEncoding, XmlRequestBehavior behavior) { return Xml(obj, null, contentEncoding, behavior); }
             public static XmlResult Xml(this Controller request, object obj, string contentType, Encoding contentEncoding, XmlRequestBehavior behavior) { return Xml(obj, contentType, contentEncoding, behavior); }
             internal static XmlResult Xml(object data, string contentType, Encoding contentEncoding, XmlRequestBehavior behavior) { return new XmlResult() { ContentEncoding = contentEncoding, ContentType = contentType, Data = data, XmlRequestBehavior = behavior }; }
         }
 }

测试

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Web;
 using System.Web.Mvc;
 namespace PaiXie.Pos.Admin
 {
     /// <summary>
     /// mvc  返回 xml 扩展
     /// </summary>
     [AllowAnonymous]
     [MvcMenuFilter(false)]
     public class TestXmlController : Controller
     {
         // GET: /TestXml/GetActionResult?type=xml
         public ActionResult GetActionResult(string type) {
             var data = new List<string>(); //注意，data必须是可被序列化的内容
             data.Add("A");
             data.Add("B");
             data.Add("C");
             a aa = new a();
             aa.a1 = "";
             b bb = new b();
             bb.b1 = "";
             aa.a2 = bb;
             if (type.ToLower() == "xml") {
                 return this.Xml(aa, XmlRequestBehavior.AllowGet);
             }
             else if (type.ToLower() == "json") {
                 return Json(aa, JsonRequestBehavior.AllowGet);
             }
             else {                  //error messages
                 return View("不支持此方法");
             }
         }

         public XmlResult GetXml() {
             var data = new List<string>(); //注意，data必须是可被序列化的内容
             data.Add("A");
             data.Add("B");
             data.Add("C");
             return this.Xml(data, XmlRequestBehavior.AllowGet);
         }
     }
     public class a {
         public string a1 { get; set; }
         public b a2 { get; set; }
     }
     public class b {
         public string b1 { get; set; }
     }
 }