如何将json ajax请求发布到Web API

Question

我无法从服务器端获取json数据。 该脚本调用服务器方法，但未返回json数据。

$(document).ready(function() {
    $("#SendMail").click(function() {
        $.ajax({
            url: "http://localhost:2457/SendMail/SendMail/",
            dataType: 'json',
            type: 'POST',
            data: "{htmlTemplate:" + "ABC" + "}",
            //crossDomain: true,
            //contentType: "application/json; charset=utf-8",
            success: function(data, textStatus, xhr) {
                console.log(data);
                alert('Successfully called');
            },
            error: function(xhr, textStatus, errorThrown) {
                // console.log(errorThrown);

            }
        });
    });
});

 Function SendMail(htmlTemplate As String) As String
      Dim fname As String = Request.Form("htmlTemplate1")
      Dim lname As String = Request.Form("lname")
      Dim cmdSendMail As New SendMailCommand()
      Return "A"
    End Function

Answer 1

<script>
$(document).ready(function () {
        $("#SendMail").click(function() {
            $.ajax({
              url: '/SendMail/SendMail/', 
              dataType: 'text',
                  type: 'POST',
                  data:JSON.stringify({htmlTemplate: "ABC"}),
              //crossDomain: true,
              contentType: "application/json; charset=utf-8",
              success: function (data, textStatus, xhr) {
               console.log(data);
                   alert('Successfully called');
                },
                error: function (xhr, textStatus, errorThrown) {
                   console.log(errorThrown);
                }
            });
        });
    });
</script>