通过ajax调用将表单值POST到C#WebMethod

<script type="text/javascript">
    $(document).ready(function () {
        $("#btn").click(function () {
            var foobar = $(this).closest('#add-question').serializeArray();
            $.ajax({
                type: "POST",url: "/Services/QuestionsService.asmx/SubmitQuestion",data: "{foo:[" + JSON.stringify(foobar) + "]}",contentType: "application/json; charset=utf-8",dataType: "json",success: function (data) {
                    $("#btn").text(data.d);
                }
            });
        });
    });
</script>

和服务：

[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
[System.ComponentModel.ToolboxItem(false)] 
[System.Web.Script.Services.ScriptService]
public class QuestionsService : System.Web.Services.WebService
{
    [WebMethod]
    public string SubmitQuestion(string foo)
    {
        //do something with foo

        return "Message Sent";
    }
}

但是我在服务上遇到了500错误：

Request format is unrecognized for URL unexpectedly ending in ‘/SubmitQuestion’.

我发现了一个类似的问题,建议添加：

<system.web>
  <webServices>
    <protocols>
      <add name="HttpGet"/>
      <add name="HttpPost"/>
    </protocols>
  </webServices>
</system.web>

对于web.config,这似乎解决了第一个问题.但我现在在服务中得到一个错误,抱怨表单参数foo缺失但它已经明确提供了：

System.InvalidOperationException: Missing parameter: foo.
at System.Web.Services.Protocols.ValueCollectionParameterReader.Read(NameValueCollection collection)
at System.Web.Services.Protocols.UrlParameterReader.Read(HttpRequest request)
at System.Web.Services.Protocols.HttpServerProtocol.ReadParameters()
at System.Web.Services.Protocols.WebServiceHandler.CoreProcessRequest()

有什么我想念的吗？

我认为这可能是serializeArray()的一个问题,因为如果我传入一个简单的json对象,它会点击web方法,例如：

var obj = { foo: 'bar' };

我是否错误地使用了serializeArray()？

以下是字符串化后的数据输出：

{
foo: [
    [
        {
            "name": "__EVENTTARGET","value": ""
        },{
            "name": "__EVENTARGUMENT",{
            "name": "__VIEWSTATE","value": "RHqOeKRh4e+2IZH9ZdPatwEklxypUzemNeDv7sO4l8vIR2TrECRFZvalrpbvVre0e6gkY9ZG3618dtU3BhYFW3YNn2y6VqeZlL5hmG/WPLTtZN8lhDkEl1bGOGWBsY52zVxWECkAC2hGtHwF5plmKsL3sHp3nFxh3yzWoGP1LwAc4sAZ/rgKvozqCp/4FfB6P4jBUQnL7Q5EkNsjWBntsXbUswC3cJpS22vgoJFHDh8Lm9n/VGzC86FUWipvGmOJ9/KVSlUBbJE3J0Fs6UZi+E6T1Ql+I8XBZlZOzDlbq40="
        },{
            "name": "ctl00$MainContent$txtName","value": "name field"
        },{
            "name": "ctl00$MainContent$txtEmailAddress","value": "email address field"
        },{
            "name": "ctl00$MainContent$txtLocation","value": "location field"
        },{
            "name": "ctl00$MainContent$chkAnonymous","value": "on"
        },{
            "name": "ctl00$MainContent$txtQuestion","value": "question field"
        },{
            "name": "__EVENTVALIDATION","value": "ileV4/vPquayqiSQJEAvq1oHpIAkHN+fy4QhqOrQpp7NxE4z15rvbTH6BfaSCFFwt96JAp1aqQzuOFCTzc6KSEE6iWDmSDRcJWWOzyksSoXpAMBwLk3F6oAaWa4EIjEUb+2b/PJobySl5BaU3TG0JCZyHK2fxj5HXd8DG89gnmVXemTwq1Ax4BgJw1Z5z1uT8Sw7Xk6inUHAZ0NJH4QdTQ=="
        }
    ]
]

}