asp.net web api2.0 ajax跨域解决方案

Web Api的优缺点就不说了,直接说怎么跨域,我搜了一下,主要是有两种。

一,ASP.NET Web API支持JSONP,分两种

  1,利用JsonMediaTypeFormatter,具体参考这里:http://www.cnblogs.com/artech/p/cors-4-asp-net-web-api-03.html

上代码:

新建JsonpMediaTypeFormatter类:

    public class JsonpMediaTypeFormatter : JsonMediaTypeFormatter
    {

        private string callbackQueryParameter;

        public JsonpMediaTypeFormatter()
        {
            SupportedMediaTypes.Add(DefaultMediaType);
            SupportedMediaTypes.Add(new MediaTypeHeaderValue("text/javascript"));

            MediaTypeMappings.Add(new UriPathExtensionMapping("jsonp", DefaultMediaType));
        }

        public string CallbackQueryParameter
        {
            get { return callbackQueryParameter ?? "callback"; }
            set { callbackQueryParameter = value; }
        }

        /// <summary>
        /// 将对象序列化后的JSON字符串填充到JavaScript回调函数中
        /// </summary>
        /// <param name="type"></param>
        /// <param name="value"></param>
        /// <param name="stream"></param>
        /// <param name="content"></param>
        /// <param name="transportContext"></param>
        /// <returns></returns>
        public override Task WriteToStreamAsync(Type type, object value, Stream stream, HttpContent content, TransportContext transportContext)
        {
            string callback;

            if (IsJsonpRequest(out callback))
            {
                return Task.Factory.StartNew(() =>
                {
                    var writer = new StreamWriter(stream);
                    writer.Write(callback + "(");
                    writer.Flush();

                    base.WriteToStreamAsync(type, value, stream, content, transportContext).Wait();

                    writer.Write(")");
                    writer.Flush();
                });
            }
            else
            {
                return base.WriteToStreamAsync(type, value, stream, content, transportContext);
            }
        }

        /// <summary>
        /// 判断是否为跨域请求
        /// </summary>
        /// <param name="callback"></param>
        /// <returns></returns>
        private bool IsJsonpRequest(out string callback)
        {
            callback = null;

            if (HttpContext.Current.Request.HttpMethod != "GET")
                return false;

            callback = HttpContext.Current.Request.QueryString[CallbackQueryParameter];

            return !string.IsNullOrEmpty(callback);
        }
    }
  • 在Global.asax中注册JsonpMediaTypeFormatter
  • GlobalConfiguration.Configuration.Formatters.Insert(0, new JsonpMediaTypeFormatter());

  2,利用ActionFilterAttribute ,具体参考这里:http://stackoverflow.com/questions/9421312/jsonp-with-asp-net-web-api/18206518#18206518

  代码:

新建 JsonCallbackAttribute 类

    public class JsonCallbackAttribute : ActionFilterAttribute
    {
        private const string CallbackQueryParameter = "callback";

        public override void OnActionExecuted(HttpActionExecutedContext actionExecutedContext)
        {
            var callback = string.Empty;
            if (IsJosnp(out callback))
            {
                var jsonBuilder = new StringBuilder(callback);
                jsonBuilder.AppendFormat("({0})", actionExecutedContext.Response.Content.ReadAsStringAsync().Result);
                actionExecutedContext.Response.Content = new StringContent("C(\"a\")");
            }
            base.OnActionExecuted(actionExecutedContext);
        }

        private bool IsJosnp(out string callback)
        {
            callback = System.Web.HttpContext.Current.Request.QueryString[CallbackQueryParameter];
            return !string.IsNullOrEmpty(callback);
        }

    }

在Global.asax中注册JsonCallbackAttribute

GlobalConfiguration.Configuration.Filters.Add(new JsonCallbackAttribute());

二,使用 Microsoft ASP.NET Web API 2 Cross-Origin Suppor

  使用 NuGe 安装 Microsoft ASP.NET Web API 2 Cross-Origin Support,这里说的很详细

  然后在Global.asax中开启针对CORS的支持,EnableCors加不加无影响的样子。

测试实例:

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <script src="http://cdn.bootcss.com/jquery/2.1.3/jquery.min.js"></script>
    <title>测试 WebApi 跨域</title>
</head>
<body>
    <form  runat="server">
        <input type="button"  value="Get 点击跨域查询数据" />
        <div >
        </div>
        <input type="button"  value="Post 点击跨域查询数据" />
    </form>
    <script>
        $('#btnGet').bind('click', function (e) {
            $.ajax({
                type: "GET",
                url: "http://localhost:20128/api/UserInfo",
                success: function (data) {
                    var html = "";
                    $.each(data, function (index, val) {
                        html += "<ul><li>GroupName: " + val.Id + " -- " + val.Name + "</li></ul>";
                    });
                    $("#bindData").append(html);
                }
            });
        });

        $('#btnPost').bind('click', function (e) {
            var user = { Id: '1', Name: '233' };
            $.ajax({
                type: "POST",
                contentType: 'application/json; charset=utf-8',
                data: JSON.stringify(user),
                url: "http://localhost:20128/api/UserInfo",
                success: function (data) {
                    //var html = "";
                    //$.each(data, function (index, val) {
                    //    html += "<ul><li>GroupName: " + val.Id + " -- " + val.Name + "</li></ul>";
                    //});
                    //$("#bindData").append(html);
                }
            });
        });

    </script>
</body>
</html>

Ajax请求在Post数据的时候,一定要加上这样项:

contentType: 'application/json; charset=utf-8',

data: JSON.stringify(user),

就这样,只是把网络上有解决方案的整理了一下,放在了一切。