在    upload.ashx  文件处理 服务器端代码

HttpPostedFile file;
                    for (int i = 0; i < context.Request.Files.Count; ++i)
                    {
                        file = context.Request.Files[i];
                        if (file == null || file.ContentLength == 0 || string.IsNullOrEmpty(file.FileName)) continue;

                        string fn = FileHelper.ReFileName(file.FileName);  //  自定义重命名方法
                        string videoPath = fileBll.VideoSavePath(fn);  //保存路径
                         file.SaveAs(videoPath);  //  保存
                    }

------------------------------------------

  控件上传 aspx 页面  的 JS

 <script type="text/javascript">
        var swfu;

        window.onload = function () {
            var settings = {
                flash_url: "../../swfupload/swfupload.swf",
                upload_url: "upload.ashx?id=<%=Key %>",
                file_size_limit: "100 MB",
                file_types: "*.*",
                file_types_description: "All Files",
                file_upload_limit: 100,
                file_queue_limit: 0,
                custom_settings: {

                    progressTarget: "divprogresscontainer",
                    progressGroupTarget: "divprogressGroup",

                    //progress object
                    container_css: "progressobj",
                    icoNormal_css: "IcoNormal",
                    icoWaiting_css: "IcoWaiting",
                    icoUpload_css: "IcoUpload",
                    fname_css: "fle ftt",
                    state_div_css: "statebarSmallDiv",
                    state_bar_css: "statebar",
                    percent_css: "ftt",
                    href_delete_css: "ftt",

                    //sum object
                    /*
                    页面中不应出现以"cnt_"开头声明的元素
                    */
                    s_cnt_progress: "cnt_progress",
                    s_cnt_span_text: "fle",
                    s_cnt_progress_statebar: "cnt_progress_statebar",
                    s_cnt_progress_percent: "cnt_progress_percent",
                    s_cnt_progress_uploaded: "cnt_progress_uploaded",
                    s_cnt_progress_size: "cnt_progress_size"
                },
                debug: false,

                // Button settings
                button_image_url: "../../images/TestImageNoText_65x29.png",
                button_width: "65",
                button_height: "29",
                button_placeholder_id: "spanButtonPlaceHolder",
                button_text: '<span class="theFont">上传文件</span>',
                button_text_style: ".theFont { font-size: 12;color:#0068B7; }",
                button_text_left_padding: 12,
                button_text_top_padding: 3,
                button_action:SWFUpload.BUTTON_ACTION.SELECT_FILE,

                // The event handler functions are defined in handlers.js
              //  file_dialog_start_handler : file_dialog_start_function,
                file_queued_handler: fileQueued,
                file_queue_error_handler: fileQueueError,
                upload_start_handler: uploadStart,
                upload_progress_handler: uploadProgress,
                upload_error_handler: uploadError,
                upload_success_handler: uploadSuccess,
                upload_complete_handler: uploadComplete,
                file_dialog_complete_handler: fileDialogComplete
            };
            swfu = new SWFUpload(settings);
        };

        var uploadComplete = function (file, server_data) {

            alert(file.name);

        };

    </script>