Question

我实现了以下下拉列表：＆lt; select style =＆＃34; margin-left：25px;＆＃34;＆gt; ＆lt; option value =＆＃34; null＆＃34;＆gt; ＆LT; /选项＆GT; ＆lt; option value =＆＃34; single＆＃34;＆gt; Single＆lt; / option＆gt; ＆lt; option value =＆＃34; in_a_relationship＆＃34;＆gt;在关系＆lt; / option＆gt;中＆lt; option value =＆＃34;订婚＆＃34;＆gt;订婚＆lt; /选项＆gt; ＆lt; option value =＆＃34;已婚＆＃34;＆gt;已婚＆lt; /选项＆gt; ＆lt; option value =＆＃34; open_rel＆＃34;＆gt;在开放式关系中＆lt; / option＆gt; ＆lt; option value =＆＃34;离婚＆＃34;＆gt;离婚＆lt; /选项＆gt; ＆LT; /选择＆GT; 比如说，用户已经从下拉菜单中选择了Single。当他们返回此页面时，我希望从列表中选择单个。对于文本字段，我只需从数据库中获取值，然后将其分配给变量，然后在值中回显它。即 $ get_data2 = mysqli_query（$ connect，＆＃34; SELECT * FROM user_bio WHERE username =＆＃39; $ username＆＃39;＆＃34;）; $ row3 = mysqli_fetch_assoc（$ get_data2）; $ bio = $ row3 [＆＃39; about_me＆＃39;]; 然后...... ＆lt; textarea name =＆＃34; biotextarea＆＃34;形式=＆＃34; change_details＆＃34;行=＆＃34; 4＆＃34; COLS =＆＃34; 60＆＃34; maxlength =＆＃34; 255＆＃34;＆gt;＆lt;？php echo $ bio; ？＆GT; ＆LT; / textarea的＆GT; 如何为select标签执行此操作？

Answer 1

在select标签上设置预选选项需要您在所选选项上放置一个选定的属性。

<select style="margin-left:25px;">
<?php
   $options = array(array("null"," "),array("single","Single"),array("in_a_relationship","In a relationship"),array("engaged","Engaged"),array("married","Married"),array("open_rel","In an open relationship"),array("divorced","Divorced"));
   foreach ($option in $options){
       if ($option[0] == $row3['status']){
           $selected = 'selected ';
       }
       else{
           $selected = '';
       }
       echo '<option '.$selected.'value="'.htmlspecialchars($option[0]).'">'.htmlspecialchars($option[1]).'</option>';
   } 
?>
 </select>

Answer 2

以下是在HTML中选择Single选项的方法：

<select style="margin-left:25px;">
     <option value="null"> </option>
     <option value="single" selected>Single</option>
     <option value="in_a_relationship">In a relationship</option>
     <option value="engaged">Engaged</option>
     <option value="married">Married</option>
     <option value="open_rel">In an open relationship</option>
     <option value="divorced">Divorced</option>
 </select>

那么，如何在PHP中设置它？！

好吧，你可以像这样生成你的<select>元素：

<?php
$options = [
    'null' => ' ',
    'single' => Single',
    'in_a_relationship' => 'In a relationship',
    'engaged' => 'Engaged',
    'married' => 'Married',
    'open_rel' => 'In an open relationship',
    'divorced' => 'Divorced'
];
?>
<select style="margin-left:25px;"><?php
     foreach($options as $key => $value) {
          echo '<option value="' . $key . '"';
          if ($key === $row3['status']){
              echo ' selected';
          }
          echo '>' . $value . '</option>';
     }
?></select>

Answer 3

Musa的解决方案没关系，但是如果你不想改变你的PHP太多你可以使用Javascript完成任务。

使用jQuery或纯Javascript

function selector(id, value){
    select = document.getElementById(id);
  for(i=0;i<select.options.length;i++){
    if(select.options[i].value == value){
        select.selectedIndex = i;
    }
  }

}
//Pure Javascript
selector("status", "engaged")

//With jQuery
jQuery('#status').val('married');

选中此Snippet

如何从<select>标记中选择一个值

3 个答案: