js原生方法 document.execCommand实现复制

copyText(text) {

      var textarea = document.createElement("input"); //创建input对象

      var currentFocus = document.activeElement; //当前获得焦点的元素

      document.body.appendChild(textarea); //添加元素

      textarea.value = text;

      textarea.focus();

      if (textarea.setSelectionRange)

        textarea.setSelectionRange(0, textarea.value.length);

      //获取光标起始位置到结束位置

      else textarea.select();

      try {

        var flag = document.execCommand("copy"); //执行复制

      } catch (eo) {

        var flag = false;

      }

      document.body.removeChild(textarea); //删除元素

      currentFocus.focus();

      return flag;

    },

handleCopyClick(address, officialAccountId) {
      this.$api.createEAHome.gethomEnvHtml().then(res => {
        console.log("gethomEnvHtml", res);
        let str1 = res.data.resMsg;
        let str2 =
          "/#/posterCenter?channelid=" +
          officialAccountId +
          "&address=" +
          address;
        let str = str1 + str2;
        let flag = this.copyText(str); //传递文本
        this.$message({
          type: flag ? "success" : "error",
          message: flag ? "复制成功！" : "复制失败！"
        });
      });
    },