2.vue使用screenfull进入全屏

 npm install --save screenfull
  import screenfull from "screenfull";
//dom
      <el-button type="primary" class="button" @click="click">按钮</el-button>
//点击函数
    click() {
      // 判断是否支持
      if (!screenfull.enabled) {
        this.$message({
          message: "不支持全屏",  
          type: "warning"
        });
        return false;
      }
      screenfull.toggle();
    }