xhr接收php://output的二进制文件，并转换成excel表格

function createObjectURL(object) { return (window.URL) ? window.URL.createObjectURL(object) : window.webkitURL.createObjectURL(object); }
            var xhr = new XMLHttpRequest();
            // var formData = new FormData();
            xhr.open('get','../a/User/user_dowload'); 
            //xhr.setRequestHeader("access-token", sessionStorage.getItem('access-token'));
            xhr.responseType = 'blob';
            xhr.onload = function (e) {
                var blob = this.response;

                var filename = '用户汇总' + getYmdHis() + ".xls";
                // console.log(this.response)
                if (window.navigator.msSaveOrOpenBlob) {
                    navigator.msSaveBlob(blob, filename);
                } else {
                    var a = document.createElement('a');
                    var url = createObjectURL(blob);
                    a.href = url;
                    a.download = filename;
                    document.body.appendChild(a);
                    a.click();
                    window.URL.revokeObjectURL(url);
                }
            };
            xhr.send(params);