提交后如何保持值仍保留在其字段中


How is it possible to keep values still in their fields after submit?

   <form action='checks.php' method='POST'>
    <div class ="bookinform">
      <table>
         <tr>
            <td>Name of Driver *</td>
            <td>
               <input type='Text' id="driver_name" name='driver_name' required autocomplete="off" size='7' maxlength='25' style='width:400px;font-family:Century Gothic' value = "">
            </td>
         </tr>
         <tr>
            <td>&nbsp;</td>
            <td></td>
         </tr>
         <tr>
            <td>Vehicle Reg *</td>
            <td>
               <input type='Text' id="Vehicle_Reg" name='Vehicle_Reg' required autocomplete="off" size='7' maxlength='15' style='width:400px;font-family:Century Gothic; text-transform:uppercase;' value = "">
            </td>
         </tr>
         <tr>
            <td>&nbsp;</td>
            <td></td>
         </tr>
         <tr>
            <td valign='top'>Haulier *</td>
            <td valign='top'>
              <input type='Text' id="query" name='haulier' style='width:400px; font-family:Century Gothic; text-transform:uppercase;' value = "">
         <tr>
            <td>&nbsp;</td>
            <td></td>
         </tr>
         </table>
     <input type='submit' name='FORM' value="Book-in Piece/s" style='width:100%;font-family:Century Gothic; margin-top:10px; color:#2EFE2E;'>
   </form>

如何在按下提交按钮后保留输入到Name of driveVehicle regHaulier中的值?我想要这个,这样就不必连续输入它们。我的表单已经作为操作转到其他地方,以便我可以在此页面上使用$_POST

需要做的就是检查该输入的值是否已POST,如果有,则echo该值。

为此,请在 val 属性中添加:

<?php if(isset($_POST["name_of_input"])) echo $_POST["name_of_input"]; ?>

。或使用三元运算符:

<?php echo(isset($_POST["name_of_input"]) ? $_POST["name_of_input"] : ""); ?>

使用 htmlspecialchars() 输出也是一种很好的做法,因为某些POST内容可能包含无效的 HTML。


完整示例

<input type='Text'
    id="driver_name"
    name='driver_name'
    required
    autocomplete="off"
    size='7'
    maxlength='25'
    style='width:400px;font-family:Century Gothic'
    value="<?php echo (isset($_POST["driver_name"]) ? htmlspecialchars($_POST["driver_name"]) : ""); ?>">

提交后可以通过以下方式维护该值:

<input type='Text' id="driver_name" name='driver_name' required autocomplete="off" size='7' maxlength='25' style='width:400px;font-family:Century Gothic' value = "<?php echo isset($_POST['driver_name']) ? $_POST['driver_name'] : NULL ?>">