js保存图片到手机相册

/保存到相册
function savePic(){
    var picurl= $("#picurl").attr("src");
    //alert(picurl);
    savePicture(picurl);
}

var triggerEvent = "touchstart";
function savePicture(Url){
    var blob=new Blob([''], {type:'application/octet-stream'});
    var url = URL.createObjectURL(blob);
    var a = document.createElement('a');
    a.href = Url;
    a.download = Url.replace(/(.*\/)*([^.]+.*)/ig,"$2").split("?")[0];
    var e = document.createEvent('MouseEvents');
    e.initMouseEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
    a.dispatchEvent(e);
    URL.revokeObjectURL(url);
}