2019-02-18 谷歌浏览器点击图片超链接实现下载而不是预览的解决办法

针对某些浏览器,比如谷歌浏览器，在超链接a标签中给出图片url，点击a标签不是期望的下载而是预览，采用以下办法可以解决。

//图片url
        imgDownload: function (url, filename) {
            var browserIsIe = this.browserIsIe();
 
            if (browserIsIe) {
                var save_link = document.createElementNS('http://www.w3.org/1999/xhtml', 'a');
                save_link.href = url;
                save_link.download = filename;
                var event = document.createEvent('MouseEvents');
                event.initMouseEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
                save_link.dispatchEvent(event);
            } else {
                window.location.href = CONTEXT_PATH + "/api/qyda/qyxx/downLoadQyxxPic?dataUrl=" + url + "&fileName=" + filename;
            }
        },
 
        //判断是否为Trident内核浏览器(IE等)函数
        browserIsIe: function () {
            if (!!window.ActiveXObject || "ActiveXObject" in window) {
                return true;
            }
            else {
                return false;
            }
        }