虽然还有其他类似的帖子，但没有一篇真正关注使用Javascript PageMethod文件上传的ASP.NET网站。我想从我的文件选择器中选择一个文件（它正在工作），并将其发送到WebMethod进行上传。
我已经设法选择了该文件并将其发送到我的WebMethod。但是，我不确定如何将该对象转换为C#中可读的格式。它是CSV文件。

Javascript：

<script>
            //formstone file drop picker library
            $(".upload").upload({
                beforeSend: onBeforeSend
            });

            function onBeforeSend(formData, file) {
                if (file.name.indexOf(".csv") < 0) {
                    return false;
                }

                //file is successfully received here
                var fd = new FormData();
                fd.append(file.name, file);
    
                //this gets called as well
                PageMethods.set_path("manage-products.aspx");
                PageMethods.UploadCSV(file, onSuccess, onFailure);

                function onSuccess(response) {
                }

                function onFailure() {
                    console.log("FAIL");
                }

                return formData;
            }
      </script>

C#Web方法：

[WebMethod]
public static void UploadCSV(object formData)
{ 
    //I'm trying to get the file data and convert to a readable file here
}