如何兼容在IE11 和主流的浏览器下载

代码如下

{
    let fileName = '文件名'
    const blobData = blobData; //blob 类型的数据

    //创建标签
    var a = document.createElement("a");
    document.body.appendChild(a);
    a.style.display = "none";

    //IE
    if (window.navigator.msSaveOrOpenBlob) {
      a.onclick = ((evx) => {
        window.navigator.msSaveOrOpenBlob(blobData, fileName);
      });
      a.click();
    }
    else //Chrome and safari
    {
      var file = URL.createObjectURL(blobData);
      a.href = file;
      a["download"] = fileName;
      a.click();
      window.URL.revokeObjectURL(file);
    }
}