我正在获取outlook日历事件的纯文本，并将其转换为ics，以便用Tampermonkey下载。
几年前我写这篇文章的时候，这个按钮还能用，但现在不行了。我不确定我现在是否需要授予权限，或者是其他什么东西破坏了它。这个按钮添加得很好，但我无法触发事件侦听器。

// .....
// @grant        none
//=====    convert text only calendar to a donwloadable ICS file
elementReady('#desc-content').then((element) => {
  //grab the relevant text
  if (element.innerHTML.includes("BEGIN:VCALENDAR")) {
    //clean up some bit
    var calendar = element.innerHTML.substring(0, element.innerHTML.length - '<div class="clearfix"></div>'.length).replace(/<br\s*[\/]?>/gi, '\n');
    //Create a button element 
    var CalendarEventButton = document.createElement("button");
    CalendarEventButton.innerHTML = 'Download Calendar Event';

    CalendarEventButton.addEventListener("click", function() {
      var filename = "CalendarInvite.ics"; //File name that will be downloaded
      download(filename, calendar); //passing in the file name and text to be downloaded
    }, false);

    element.appendChild(CalendarEventButton); //append the button to the document
  }
});

/* Download an embedded file/text*/
function download(file, text) {

  //creating an invisible element
  var element = document.createElement('a');
  element.setAttribute('href',
    'data:text/calendar;charset=utf-8, ' +
    encodeURIComponent(text));
  element.setAttribute('download', file);

  // Above code is equivalent to
  // <a href="path of file" download="file name">

  document.body.appendChild(element);

  //onClick property
  element.click();

  document.body.removeChild(element);
}