对不起，我的英语不好。我无法从jquery相关下拉菜单中选择选项值。我有三个下拉菜单第一类，第二是子类和第三是子类。默认情况下，在进入和更新模式下，第2和第3菜单始终处于禁用状态。我可以在类别下拉框中选择用户已经选择但无法在子类别和子类别菜单中选择的类别。下面是我的完整代码：

[控制器]

public function productEditAction($id)
{
    $product = Products::findFirstByid($id);

    $this->view->id = $product->id;
    $this->view->setVar('pcid', $product->category_id);
    $this->view->setVar('pscid', $product->subcategory_id);
    $this->view->setVar('psscid', $product->sscid);

    $category = Categories::find();
    $this->view->setVar('categories',$category);
    $this->view->pick("index/entry");

}

public function getSubcategoryAction()
{ 
    $this->view->disable();
    $id = $this->request->getPost('id');
    $data = Subcat::findBycategory_id($id); 
    $resData = array();    
    foreach($data as $result)
    {
        $resData[] = array('id' => $result->id, 'category_id' => $result->category_id, 'subcategory' => $result->subcategory_name);
    }
    echo(json_encode($resData));       
}
public function getsscAction()
{ 
    $this->view->disable();
    $id = $this->request->getPost('id');
    $data = Ssc::findBysubcatid($id);  
    $resData = array();    
    foreach($data as $result)
    {
        $resData[] = array('id' => $result->id, 'subcatid' => $result->subcatid, 'ssctitle' => $result->ssctitle);
    }
    echo(json_encode($resData));       
}

[jquery]

//Dependent List Category Action
$("select[name='category']").on("change", function(e){
    e.preventDefault();
    var value = $(this).val();
    if(value === '0'){$("select[name='subcategory']").attr("disabled", true); $("select[name='ssc']").attr("disabled", true);}else{$("select[name='subcategory']").attr("disabled", false);} 
    $.ajax({
        type: "POST",
        url: "http://localhost/shopping/backend/index/getSubcategory",
        data:'id='+value,       
    }).done(function(response){
        $("#subcategory").find('option').not(":first").remove();    
        $("#ssc").find('option').not(":first").remove();
        response = JSON.parse(response);
        response.forEach(function(value){
            $('#subcategory').append('<option value="'+value.id+'">'+value.subcategory+'</option>');
        });
    }).fail(function(){
            console.log('error: Please reload page and try again!');
    }).always(function(){
            console.log('Complete:');
    });
});
//Dependent List Sub-Category Action
$("select[name='subcategory']").on('change', function(e){
    e.preventDefault();
    var value = $(this).val();
    if(value === '0'){$("select[name='ssc']").attr("disabled", true);}else{$("select[name='ssc']").attr("disabled", false);}    
    $.ajax({
        type: "POST",
        url: "http://localhost/shopping/backend/index/getssc",
        data:'id='+value,       
    }).done(function(response){     
            $("#ssc").find('option').not(":first").remove();
            response = JSON.parse(response);
            response.forEach(function(value){               
                $('#ssc').append('<option value="'+value.id+'">'+value.ssctitle+'</option>');
            });
    }).fail(function(){
            console.log('error: Please reload page and try again!');
    }).always(function(){
            console.log('Complete:');
    });
});

[表格]

Category: 
<select name="category">
    <option value="0">Choose Category ...</option>
    {% for category in categories %}
        <option value="{{category.id}}" {% if category.id === pcid %}selected="selected"{% endif %}>{{category.categoryname}}</option>
    {% endfor %}
</select><br/>
sub-Category:<select name="subcategory" id="subcategory" disabled="disabled"><option value="0">Choose Sub-Category ...</option></select><br/>
Sub-Sub-Category:<select name="ssc" id="ssc" disabled="disabled"><option value="0">Choose Sub-Sub-Category ...</option></select><br/>