复制功能

  export function copyText(txt) {
 const transfer = document.createElement('input');
 document.body.appendChild(transfer);
 transfer.value = txt; // 这里表示想要复制的内容
 transfer.focus();
 transfer.select();
 if (document.execCommand) {
   document.execCommand('copy');
   message.success('复制成功');
 }
 transfer.blur();

 document.body.removeChild(transfer);
}