【1】下载安装

npm install screenful -s

【2】在项目vue中配置

import screenfull from "screenfull";

【3】给按钮添加事件

在methods里面定义方法：

 screenFull() {
      if (!screenfull.enabled) {
        this.$message({
          message: "不支持全屏",
          type: "warning",
        });
        return;
      }
      screenfull.toggle();
    },