Question

此代码允许某人从下拉菜单中选择一个类，我将数字转换为字母。现在我想将所选值发送回服务器：

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如何从下拉菜单中传递选定的值＆＃39; class＆＃39;到服务器？我可以传递代码，但不知道如何传递选定的类。

Answer 1

要将所选类添加到URL，您需要在JavaScript中构建URL，因为PHP事先不知道用户将选择什么。这是你的代码（只有通过SQL的部分。在评论中我描述了我做的一些改进（与你的问题无关）：

<?php
// Make your query return ALL you need. Avoid second query:
$query = "SELECT     class.code, class.name, class.hours, classtot.total
          FROM       class
          INNER JOIN classtot ON classtot.code = class.code";
$result = mysqli_query($connection,$query) or die ("Couldn’t execute query.");

// Keep track of row number, for use in generating unique id property values 
$rowIndex = 0;
while($row = mysqli_fetch_assoc($result))
{
    $rowIndex++;
    echo "<tr>                              
             <td>$row[code]</td>
             <td>$row[name]</td>
             <td>$row[hours]</td>";
    // Just pick the total from the combined query:
    $a = $row['total'];
    $alphabet = range('A','Z');
    // Change id for select: You cannot assign the same id to several elements
    echo "
    <td><select id='select$rowIndex' data-rel='chosen' name='class' >";
    // Use a zero-based for loop instead of a while
    for ($i = 0; $i < $a; $i++)
    {
        // Reference $i now, not $i-1:
        $kls = $alphabet[$i];
        echo "<option value='$kls'> $kls </option>";
    }
    // Instead of hard-coding the URL, call a JS function that will make the url
    echo "</select></td>
    <td> 
    <a class='btn btn-primary btn-addon m-b-sm btn-xs' href='#'
       onclick='gotoClass($rowIndex, \"$row[code]\")'>
    <i class='fa fa-plus'></i> Add</a>
    </td>
    </tr>";
}

?>
    </tbody>
</table>
<script>
    // The JS function that builds the URL and triggers the navigation to it
    function gotoClass(rowIndex, classCode) {
        var sel = document.getElementById('select' + rowIndex);
        location.href = 'home_member.php?page=add&id=' + classCode 
                      + '&something=' + sel.value;
        return false; 
    }
</script>

在上面的代码中，您需要更改＆＃34;某些内容＆＃34;要使用正确的URL参数来传递所选的＆＃34;字母表＆＃34;值。

如果表行中有另一个select，请执行以下操作：

<select id='select2$rowIndex' data-rel='chosen' name='code' >

然后扩展上面的javascript函数如下：

    function gotoClass(rowIndex, classCode) {
        var sel = document.getElementById('select' + rowIndex);
        var sel2 = document.getElementById('select2' + rowIndex);
        location.href = 'home_member.php?page=add&id=' + classCode 
                      + '&something=' + sel.value
                      + '&othervalue=' + sel2.value;
        return false; 
    }

生成下拉列表，将列出的选定项目发送回服务器

1 个答案: