a标签下载 mp3、png、vtt、srt 等文件到本地，亲测有效

下载 mp3、png、vtt、srt 等文件到本地，亲测有效

export const downloadFromUrl = (url: string, name?: string) => {
  try {
    const ajax = new XMLHttpRequest();
    ajax.open('GET', url.replace('http://', 'https://'), true);
    ajax.responseType = 'blob';
    
    ajax.onload = function() {
      const content = ajax.response;
      let src = (window.URL || window.webkitURL).createObjectURL(new Blob([content]));
      const a = document.createElement('a');
      a.href = src;
      a.download = name || '';
      document.body.appendChild(a);
      a.click();
      document.body.removeChild(a);
    }
    ajax.send();
  } catch(e) {
    console.log('download: ', e);
  }
}