XHR2：让使用纯JS实现上传进度条变成了可能

$.ajax({

                xhr: function () {

                    var xhr = new window.XMLHttpRequest();

                    xhr.upload.addEventListener("progress", function (evt) {

                        if (evt.lengthComputable) {

                            var percentComplete = parseInt(evt.loaded / evt.total * 100) + "%";

                            config.progress.find('.prog').css({ 'height': percentComplete, 'background': "rgba(209,3,17,.5)" });

                            config.progress.find('.number').html(percentComplete);

                        }

                    }, false);

                    return xhr;

                },

                type: 'POST',

                url: lanh.apiHost + "service/user/upload.html",

                data: {

                    type: config.type,

                    filename: config.filename,

                    pic: config.pic

                },

                success: function (data) {

               }

 

相关辅助网址：http://blog.sina.com.cn/s/blog_54da57aa01016n9i.html