组合 - 选择启用/禁用

Question

我有 3 个组合框（选择），如果我从第一个选项中选择一个选项，我需要启用第三个。

• 类别（启用）
• 子类别（禁用）
• 葡萄（禁用）

如果我从categories中选择Wines则需要启用grapes

$('#subcategories').attr('disabled','disabled');
$('#grapes').attr('disabled','disabled');
$("#categories").change(function () {
$("#categories option:selected").each(function () {
    var v_elegido=$(this).val();    
    $('#subcategories').removeAttr('disabled');
    if($(this).val() == "Vinos")  {
        $('#grapes').removeAttr('disabled');
    } else {
        $('#grapes').attr('disabled','disabled');
    }
    $.post("subcategories.php", { elegido: v_elegido }, function(data){
        $("#subcategories").html(data);
    });  

});


 <?php if ($campo == 'varietales') { ?>    
    <div class="col_texto" align="right"><?php echo $campo ?>:&nbsp;</div>
  <div id="varietal" style="visibility:visible;">
        <select name="varietales" id="varietales">
        <option value="0">-</option>
        <?php
            $conn = DataBase::getInstance();
                $rel=false;
                $relacion='_'.$campo;
                $conn->setQuery('SELECT * FROM `_'.$campo.'` ORDER BY id ASC');
                if ($conn->len()==0){
                    $rel=true;
                    $relacion=$campo;
                    $conn->setQuery('SELECT * FROM `'.$campo.'` ORDER BY id ASC');
                }
                if ($conn->len()==0){
                    $rel=true;
                    $relacion=$campo.'s';
                    $conn->setQuery('SELECT * FROM `'.$campo.'s` ORDER BY id ASC');
                }
                if ($conn->len()>0){
                $rs = $conn->loadObjectList();
                foreach($rs as $valor){?>
            <option value="<?php echo $valor->id ?>"><?php echo $valor->titulo ?></option>
            <?php 
                }}?>
            </select> 
      </div>      
         <?php } else { ?>
    <?php if ($campo == 'bodegas') { ?>    
    <div class="col_texto" align="right"  style="visibility:visible;"><?php echo $campo ?>:&nbsp;</div>
  <div>
        <select name="bodegas" id="bodegas">
        <option value="0">-</option>
        <?php
            $conn = DataBase::getInstance();
                $rel=false;
                $relacion='_'.$campo;
                $conn->setQuery('SELECT * FROM `_'.$campo.'` ORDER BY id ASC');
                if ($conn->len()==0){
                    $rel=true;
                    $relacion=$campo;
                    $conn->setQuery('SELECT * FROM `'.$campo.'` ORDER BY id ASC');
                }
                if ($conn->len()==0){
                    $rel=true;
                    $relacion=$campo.'s';
                    $conn->setQuery('SELECT * FROM `'.$campo.'s` ORDER BY id ASC');
                }
                if ($conn->len()>0){
                $rs = $conn->loadObjectList();
                foreach($rs as $valor){?>
            <option value="<?php echo $valor->id ?>"><?php echo $valor->titulo ?></option>
            <?php 
                }}?>
            </select> 
      </div>      
         <?php } else { ?>
   <?php if ($campo == 'subcategorias') { ?>    
    <div class="col_texto" align="right"><?php echo $campo ?>:&nbsp;</div>
  <div>
        <select name="<?php echo $campo ?>" id="<?php echo $campo ?>">
        <option value="0">-</option>
        <?php
            $conn = DataBase::getInstance();
                $rel=false;
                $relacion='_'.$campo;
                $conn->setQuery('SELECT * FROM `_'.$campo.'` ORDER BY id ASC');
                if ($conn->len()==0){
                    $rel=true;
                    $relacion=$campo;
                    $conn->setQuery('SELECT * FROM `'.$campo.'` ORDER BY id ASC');
                }
                if ($conn->len()==0){
                    $rel=true;
                    $relacion=$campo.'s';
                    $conn->setQuery('SELECT * FROM `'.$campo.'s` ORDER BY id ASC');
                }
                if ($conn->len()>0){
                $rs = $conn->loadObjectList();
                foreach($rs as $valor){?>
            <option value="<?php echo $valor->id ?>"><?php echo $valor->titulo ?></option>
            <?php 
                }}?>
            </select>
    </div>        

         <?php  } else { ?> 

         <div class="col_texto" align="right"><?php echo $campo ?>:&nbsp;</div>
         <div>
        <select name="categorias" id="categorias">
        <option value="0">-</option>
        <?php
            $conn = DataBase::getInstance();
                $rel=false;
                $relacion='_'.$campo;
                $conn->setQuery('SELECT * FROM `_'.$campo.'` ORDER BY id ASC');
                if ($conn->len()==0){
                    $rel=true;
                    $relacion=$campo;
                    $conn->setQuery('SELECT * FROM `'.$campo.'` ORDER BY id ASC');
                }
                if ($conn->len()==0){
                    $rel=true;
                    $relacion=$campo.'s';
                    $conn->setQuery('SELECT * FROM `'.$campo.'s` ORDER BY id ASC');
                }
                if ($conn->len()>0){
                $rs = $conn->loadObjectList();
                foreach($rs as $valor){?>
            <option value="<?php echo $valor->id ?>"><?php echo $valor->titulo ?></option>
            <?php 
                }}?>
            </select>
           </div>  
         <?php } ?>      
         <?php } ?>          
         <?php } ?>  

Answer 1

所以你需要做的就是获取val..并相应地设置禁用的属性

$("#categories").change(function(){
    $('#grapes').prop('disabled',$(this).val() != 'Vinos');
});

这是假设您的选项有值，并且您第一个选择的第三个选项是"Vinos"

.prop（） 也是设置禁用属性的首选方法，因为 jQuery 1.6+

应该使用 .prop（） 方法来设置禁用和检查，而不是 .attr（） 方法