我添加了一个复制json内容到剪切板的按钮

<a href="javascript:void(0);" onclick="CopyTxt()">复制</a>

//复制到剪切板
function CopyTxt(){
  let content=$id("Canvas").innerText;
  let txa = document.createElement('textarea')
  let txval = content
  // console.log('copy val:', txval)
  txa.value = txval
  document.body.appendChild(txa)
  txa.select()
  let res = document.execCommand('copy')
  document.body.removeChild(txa)
  console.log('copy success')
}