js防windos锁屏功能实现

<li class="layui-nav-item">
    <a href="javascript:;" id="lock">
         <i class="iconfont icon-diannao1"></i>
     锁屏</a>
</li>

<div class="lock-screen" style="display: none;">
    <div id="locker" class="lock-wrapper">
        <div id="time"></div>
        <div class="lock-box center">
            <img src="/static/images/user.jpg" style="100px;height:100px;" alt="">
            <h1>admin</h1>
            <duv class="form-group col-lg-12">
                <input type="password" placeholder='锁屏状态，请输入密码解锁' id="lock_password" class="form-control lock-input" autofocus name="lock_password">
                <button id="unlock" class="btn btn-lock">解锁</button>
            </duv>
        </div>
    </div>
</div>

 // 快捷键锁屏设置
    $(document).keydown(function(e){
         if(e.altKey && e.which == 76){
              lockSystem();
         }
    });
   function startTimer(){
           var today=new Date();
        var h=today.getHours();
        var m=today.getMinutes();
        var s=today.getSeconds();
        m = m < 10 ? '0' + m : m;
        s = s < 10 ? '0' + s : s;
        $('#time').html(h+":"+m+":"+s);
        var t=setTimeout(function(){startTimer()},500);
   }
   // 锁屏状态检测
   function checkLockStatus(locked){
        // 锁屏
        if(locked == 1){
            $('.lock-screen').show();
            $('#locker').show();
            $('#layui_layout').hide();
            $('#lock_password').val('');
        }else{
            $('.lock-screen').hide();
            $('#locker').hide();
            $('#layui_layout').show();
        }
    }

   checkLockStatus('0');
   // 锁定屏幕
   function lockSystem(){
           
          var url = '';
          $.post(
                 url,
                 function(data){
                     if(data){
                           checkLockStatus(1);
                     }else{
                  layer.alert('锁屏失败，请稍后再试！');
                     }
              });
          startTimer();
   }
   //解锁屏幕
   function unlockSystem(){
        // 与后台交互代码已移除，根据需求定义或删除此功能
        
           checkLockStatus(0);
    }
   // 点击锁屏
   $('#lock').click(function(){
           lockSystem();
   });
   // 解锁进入系统
   $('#unlock').click(function(){
        unlockSystem();
   });
   // 监控lock_password 键盘事件
   $('#lock_password').keypress(function(e){
        var key = e.which;
        if (key == 13) {
            unlockSystem();
        }
    });