function printscreenScene() {

         var image = new Image();//创建img对象

         viewer.render();//重新渲染界面

         image = viewer.scene.canvas.toDataURL("image/png");

         $("#printscreenScene_save").find("img").attr("src", image);//添加img标签元素

         $("#printscreenScene_save img").show().addClass("show");

         saveFile(image, 111);//调用打印图件函数

     }

     //打印图件

     var saveFile = function (data, filename) {

         var save_link = document.createElementNS('http://www.w3.org/1999/xhtml', 'a');

         save_link.href = data;

         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);

     };