About PHP not receiving POST information from form submission

After debugging for a long time, the data accepted by the dump was always NULL. I thought there was a problem with the verification function of ThinkPHP. After commenting it, it still didn't work. I checked that the id written on the view also corresponded. There was no error in each field. Finally, I found it. Now:

Both the id and name must be written on the html form in View. It seems to be HTML common sense...

   <div class="form-group ">
      <label for="dormitory_num" class="col-sm-2 control-label">宿舍号</label>
      <div class="col-sm-4">
         <input type="text" id="dormitory_num" name="dormitory_num" 
            placeholder="格式:13#225" class="form-control">
      </div>
   </div>

The above introduces the POST information about PHP not receiving form submission, including the content. I hope it will be helpful to friends who are interested in PHP tutorials.