ASP.NET MVC接收从ajax传过来的json数据

由于模型绑定接收数据经常出现问题，所以使用了原始的方法接收从前台用ajax提交过来的数据：

下面是示例代码：

前台：

// 表单提交
                    form.on('submit(formSubmit)', function (data) {
                        layer.msg(JSON.stringify(data.field));
                        //data.field.F_Photo = document.getElementById("preview").src;
                        delete data.field.file;
                        // ajaxa提交
                        console.log(JSON.stringify(data.field));
                        var formData = JSON.stringify(data.field);
                        console.log('formData: ' + formData);
                        $.ajax({
                            url: "/TrainingManage/Certificate/Get",
                            data: formData,
                            processData: false,
                            contentType: false,
                            type: "post",
                            dataType: "json",
                            success: function (data) {
                                if (data.state == "success") {
                                    $('#picCertificate').attr("src", data.data);
                                    console.log(data.data);
                                    layer.alert(data.message, {
                                        icon: 1,
                                        skin: 'layer-ext-moon'
                                    });

                                } else {
                                    layer.alert(data.message, {
                                        icon: 1,
                                        skin: 'layer-ext-moon'
                                    });
                                }
                            },
                            error: function (data) {
                                layer.alert('提交数据失败', {
                                    icon: 1,
                                    skin: 'layer-ext-moon'
                                });
                            }
                        });

                    });

后台接收数据：

        public ActionResult GetData()
        {
            var sr = new StreamReader(Request.InputStream);
            var stream = sr.ReadToEnd();
            var entity = JsonConvert.DeserializeObject<CertificateEntity>(stream);

            if (ModelState.IsValid)
            {

                ...
                return Content(resultdata.ToJson());
            }
            var result = new
            {
                state = "fail",
                message = "生成证书失败",
                data = ""
            };
            return Content(result.ToJson());
        }