用JS写个简单的抢课脚本

<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">环境：火狐浏览器   插件：Greasemonkey 与 ReloadEvery</span>

在插件配置好之后就可以进行操作。由于抢课系统已关闭，这里我就写一个小程序来模拟下

其中Greasemonkey是用于储存脚本，ReloadEvery是用于不断刷新运行脚本

我这里假设html代码为网页的代码，JS为我们所嵌入运行的代码

模拟抢课首页：index.html

<meta charset="utf-8">
<form action="01.html" action="post" id="form1">
  <table>
    <tr>
      <td><input type="checkbox" id="checkbox" value="1.1" name="test">1.1</td>
      <td>1.2</td>
      <td>1.3</td>
    </tr>
    <tr>
      <td>2.1</td>
      <td>2.2</td>
      <td>2.3</td>
    </tr>
    <tr>
      <td>3.1</td>
      <td>3.2</td>
      <td>3.3</td>
    </tr>
  </table>
  <table>
    <tr>
      <td>1.11</td>
      <td>1.22</td>
      <td>1.33</td>
    </tr>
    <tr>
      <td>2.11</td>
      <td>2.22</td>
      <td>2.33</td>
    </tr>
    <tr>
      <td>3.11</td>
      <td>3.22</td>
      <td>3.33</td>
    </tr>
  </table>
  <input type="submit" id="selOK" vaule="提交">
</form>


<script>
  function test(){
  var flag = false;
    var trs = document.getElementById('form1').getElementsByTagName('table')[0].getElementsByTagName('tr');
    for(var i = 0; i < trs.length; ++i){
      var tds = trs[i].getElementsByTagName('td')[0];
      if((tds.innerHTML != "1.2")) {
        var tdsTmp = trs[i].getElementsByTagName('td');
        alert(tdsTmp[0].getElementsByTagName('input')[0].value);
        tdsTmp[0].getElementsByTagName('input')[0].checked=true;
        flag = true;
        break;
      }
    }
    if (flag == true) {
      document.getElementById('selOK').click();
      alert('666');
    }
  }

setInterval(test, 2500);
</script>

中间跳转页：01.html

<script>
  window.location.href="selected.html";
</script>

抢课提交页：selected.html

<meta charset="utf-8">
<form action="index.html" οnsubmit="javascript:alert('选课成功,即将返回继续选课');">
  <input type="submit" value="确定选课" id="selOk">
</form>
<script>
  var sel = document.getElementById('selOk');
  sel.click();
</script>

重点是：1、获取节点getElementById 与 getElementsByTagName

2、在JS提交 xxx.click() 或 xxx.submit()

3、中转站跳转返回 window.location.href="xxxx.xx"