wcf服务json 400错误请求

Question

I get a 400 Bad Request error when I try to call WCF service from client side using ajax. Following is my code,

[OperationContract]
[WebInvoke(Method = "POST",
BodyStyle = WebMessageBodyStyle.Wrapped,
ResponseFormat = WebMessageFormat.Json)]
string[] GetUser(string Id);

$.ajax({
                type: "POST", //GET or POST or PUT or DELETE verb
                url: "http://localhost:58055/Service1.svc/GetUser", 
                crossDomain: true,
                data: '{"Id": "3"}',
                contentType: "application/json; charset=utf-8", 
                dataType: "json", //Expected data format from server
                processdata: true, //True or False
                success: function (msg) {//On Successfull service call
                    alert(msg.GetUserResult[0]);
                    console.log("success " + msg);
                },
                error: function (msg) {//On Successfull service call
                    console.log(msg);
                }
            });

Any insights would be really helpfull...

Answer 1

The first thing you should try is hit the URL using fiddler(so that you could post your data too) and see if you get the same error.

Are you making a cross domain request. From the example it looks like you are not. Could you remove

crossDomain: true,

line and try the jquery again.

There are other options also which unnecessay like processdata. Suggest you to use the following code and see if it works or not.

$.ajax({
            type: "POST",
        // the url to the service - 
        url: "url",
        // the format that the data should be in when
        // it is returned
        contentType: "json",
            data: '{"Id": "3"}',
        // the function that executes when the server
        // responds to this ajax request successfully
        success: function(data) {

        // put the JSON response in the employees table

        }

Answer 2

According to the ajax api documentation the default content type is 'application/x-www-form-urlencoded'. When sending JSON, the content type should be 'application/json; charset=utf-8' except that WCF does not like that. I got the same error messages and when I removed the content type I stopped getting this error. By the way, I noticed that you set crossDomain to true, this other question is relevant to that option.