前端下载文件兼容IE

之前做的下载文件并兼容IE，当时搜了好几篇博客，才写出来。现在拿出来分享下，希望能够直接帮到大家，欢迎指正问题~

    let param = {      projectId,    }    let url = '/xxx/xxx';    axios.post(url,param,{responseType: 'blob'})      .then((response) => {        let res = response.data;        if (res["content-type"] && res["content-type"].indexOf('application/json') !== -1) {          let reader = new FileReader();          reader.readAsText(res, 'utf-8');          reader.onload = function (e) {            let data = JSON.parse(reader.result);   //e.target.result也可            if(data.msg){              message.error(data.msg);            }                     }        }else{          let blob = new Blob([response.data])          let downloadElement = document.createElement('a');          let href = window.URL.createObjectURL(blob); //创建下载的链接          let fileName = response.headers["content-disposition"].split(";")[1].split("filename=")[1];          if (isIE) {            window.navigator.msSaveBlob(blob, fileName);          } else {            downloadElement.href = href;        　　downloadElement.download = fileName; //下载后文件名        　　document.body.appendChild(downloadElement);        　　downloadElement.click(); //点击下载        　　document.body.removeChild(downloadElement); //下载完成移除元素        　　window.URL.revokeObjectURL(href); //释放掉blob对象           }        }      })      .catch((err) => {        console.error(err)      });