从字符串创建文件并下载

var blob = new Blob([str], { type: 'text/plain' });

var downloadLink = document.createElement('a');
downloadLink.href = URL.createObjectURL(blob);

downloadLink.download = 'filename.txt';
downloadLink.target = '_blank';

document.body.appendChild(downloadLink);
downloadLink.click();
document.body.removeChild(downloadLink);

function createAndDownloadFileFromString(str, filename) {
  var blob = new Blob([str], { type: 'text/plain' });

  var downloadLink = document.createElement('a');
  downloadLink.href = URL.createObjectURL(blob);
  downloadLink.download = filename;
  downloadLink.target = '_blank';

  document.body.appendChild(downloadLink);
  downloadLink.click();
  document.body.removeChild(downloadLink);
}

// 调用函数创建并下载文件
var content = 'This is the content of the file.';
var fileName = 'example.txt';
createAndDownloadFileFromString(content, fileName);