我有类别\'news\' http://localhost/foldername/news, 对于每个\'news\' 我的自定义字段名为\'years\' 并设置为文本字段。我在不同的岗位上分配了2个值\'2013\' 和\'2014\'.

我首先要做的只是展示2014 在中发布\'news\' 类别http://localhost/foldername/news 第二个是传递url参数，所以如果我想显示\'2013\' 要使用以下内容http://localhost/foldername/news/?years=2013

我已经选择了属性，所以用户将选择显示哪一年的帖子，但默认情况下将显示2014年的帖子

 <select>
  <option value="2014">2014</option>
  <option value="2013">2013</option>
</select>

第一次，我发现以下解决方案仅显示\'2014\' 在中发布\'news\' http://localhost/foldername/news:

    $args= array(   
    \'meta_key\' => \'years\',
    \'meta_value\' => \'2014\',
    );
   query_posts($args);

现在我最大的问题是我传递参数来显示\'2013\' 发布但不起作用

尝试了以下操作：

function wpse129223_custom_meta_query( $query ) {

    // If not on the main query, or on an admin page, bail here
    if ( ! $query->is_main_query() || is_admin() ) {
    return;
}

// If \'type\' isn\'t being passed as a query string, bail here
if ( empty( $_GET[\'years\'] ) ) {
    return;
}

// Get the existing meta query, cast as array
$meta_query = (array) $query->get(\'meta_query\');

    // Convert \'type\' into an array of types
    $types = explode( \',\', $_GET[\'years\'] );

    // Ensure that types aren\'t empty
    if ( is_array( $types ) && ! empty( $types ) ) {

        // Build a meta query for this type
        $meta_query[] = array(
            \'key\'     => \'years\',
            \'value\'   => $types,
            \'compare\' => \'IN\',
        );

        // Update the meta query
        $query->set( \'meta_query\', $meta_query );
    } 

}
add_action( \'pre_get_posts\', \'wpse129223_custom_meta_query\' );

但每次我去http://localhost/foldername/news/?years=2013 还是给我看\'2014\' 职位

function wpse129223_custom_meta_query( $query ) {

    // If not on the main query, or on an admin page, bail here
    if ( ! $query->is_main_query() || is_admin() || ! $query->is_category( \'news\' ) ) {
        return;
    }

    // Get the existing meta query, cast as array
    $meta_query = (array) $query->get(\'meta_query\');

    // Convert \'type\' into an array of types
    $types = explode( \',\', empty( $_GET[\'years\'] ) ? \'2014\' : $_GET[\'years\'] );

    // Ensure that types aren\'t empty
    if ( is_array( $types ) && ! empty( $types ) ) {

        // Build a meta query for this type
        $meta_query[] = array(
            \'key\'     => \'years\',
            \'value\'   => $types,
            \'compare\' => \'IN\',
        );

        // Update the meta query
        $query->set( \'meta_query\', $meta_query );
    } 

}
add_action( \'pre_get_posts\', \'wpse129223_custom_meta_query\' );