ASP.NET Web APIを操作するにはどうすればよいですか?

public class UserModel{public string UserID { get; set; }public string UserName { get; set; }
}

public class UserController : ApiController{public UserModel getAdmin()
    {return new UserModel() { UserID = "000", UserName = "Admin" };
    } 
}

public static void Register(HttpConfiguration config)
{
    config.Routes.MapHttpRoute(
        name: "DefaultApi",
        routeTemplate: "api/{controller}/{id}",
        defaults: new { id = RouteParameter.Optional }
    );
}

protected void Application_Start(object sender, EventArgs e)
{WebApiConfig.Register(GlobalConfiguration.Configuration);
}

$.ajax({
    type: 'GET',
    url: 'api/user/getadmin',
    dataType: 'json',
    success: function (data, textStatus) {
        alert(data.UserID + " | " + data.UserName);
    },
    error: function (xmlHttpRequest, textStatus, errorThrown) {
    }
});

public bool add(UserModel user)
{return user != null;
}

<input type="button" name="btnOK" id="btnOK" value="发送POST请求" />

$('#btnOK').bind('click', function () {//创建ajax请求，将数据发送到后台处理var postData = {
        UserID: '001',
        UserName: 'QeeFee'};
    $.ajax({
        type: 'POST',
        url: 'api/user/add',
        data: postData,
        dataType: 'json',
        success: function (data, textStatus) {
            alert(data);
        },
        error: function (xmlHttpRequest, textStatus, errorThrown) {
        }
    });
});