jQuery表单插件:在IE8/IE9中没有调用uploadProgress

Question

我在我的项目中使用jQuery表单插件(jquery.form.js).它在Chrome/FF中工作正常,但在IE8/9中,没有调用uploadProgress回调.甚至官方网站http://jquery.malsup.com/form/progress.html上的演示也不会更新IE8/9中的上传进度.任何提示？谢谢.

Answer 1

从来源:

    if (options.uploadProgress) {
        // workaround because jqXHR does not expose upload property
        s.xhr = function() {
            var xhr = jQuery.ajaxSettings.xhr();
            if (xhr.upload) {
                xhr.upload.onprogress = function(event) {
                    var percent = 0;
                    var position = event.loaded || event.position; /*event.position is deprecated*/
                    var total = event.total;
                    if (event.lengthComputable) {
                        percent = Math.ceil(position / total * 100);
                    }
                    options.uploadProgress(event, position, total, percent);
                };
            }
            return xhr;
        };
    }

它使用ie8/9不支持的HTML5功能:

>> "upload" in new XMLHttpRequest 
false