怎么为WordPress小工具添加CSS类选项

下面由WordPress教程栏目给大家介绍怎么为WordPress小工具添加CSS类选项，希望对需要的朋友有所帮助！

WordPress 小工具可以重复使用，相同的小工具样式也是相同的，如果想自定义某个前台添加的小工具样式，与其它不同，可以通过查看原代码，找到它的id，比如搜索小工具会看到类似的：

<section id="search-2" class="widget widget_search">

其中search-2就是这个小工具的ID，可以用#search-2定义样式，不过这个后缀的编号并不是固定的，下次添加可能会变，需要再次编辑之前的样式，有些麻烦。

可以通过下面的代码，给现有的小工具统一增加CSS类选项，将代码添加到当前主题函数模板functions.php中即可，效果如图：

代码一　

只加一个CSS类选项

function zm_widget_form_extend( $instance, $widget ) {   if ( !isset($instance['classes']) ) $instance['classes'] = null; $row = "<p>n"; $row .= "t<label for='widget-{$widget->id_base}-{$widget->number}-classes'>CSS类</label>n"; $row .= "t<input type='text' name='widget-{$widget->id_base}[{$widget->number}][classes]' id='widget-{$widget->id_base}-{$widget->number}-classes' class='widefat' value='{$instance['classes']}'/>n"; $row .= "</p>n"; echo $row; return $instance; } add_filter('widget_form_callback', 'zm_widget_form_extend', 10, 2);   function zm_widget_update( $instance, $new_instance ) { $instance['classes'] = $new_instance['classes']; return $instance; } add_filter( 'widget_update_callback', 'zm_widget_update', 10, 2 );   function zm_dynamic_sidebar_params( $params ) { global $wp_registered_widgets; $widget_id    = $params[0]['widget_id']; $widget_obj    = $wp_registered_widgets[$widget_id]; $widget_opt    = get_option($widget_obj['callback'][0]->option_name); $widget_num    = $widget_obj['params'][0]['number'];   if ( isset($widget_opt[$widget_num]['classes']) && !empty($widget_opt[$widget_num]['classes']) ) $params[0]['before_widget'] = preg_replace( '/class="/', "class="{$widget_opt[$widget_num]['classes']} ", $params[0]['before_widget'], 1 ); return $params; } add_filter( 'dynamic_sidebar_params', 'zm_dynamic_sidebar_params' );

代码二　

添加ID及CSS类下拉选项

function zm_widget_form_extend( $instance, $widget ) { if ( !isset( $instance['classes'] ) ) $instance['classes'] = null;   if ( !isset( $instance['custom_id'] ) ) $instance['custom_id'] = null;   $class_prefix = 'widget-';  $myclass = array( 'default'  => '默认', 'blue'     => '蓝色', 'yellow'   => '黄色', 'black'    => '黑色', );   $row = "<p>n"; $row .= "t<label for='widget-{$widget->id_base}-{$widget->number}-custom_id'>添加ID</label>n"; $row .= "t<input type='text' name='widget-{$widget->id_base}[{$widget->number}][custom_id]' id='widget-{$widget->id_base}-{$widget->number}-custom_id' class='widefat' value='{$instance['custom_id']}' />n"; $row .= "t<label for='widget-{$widget->id_base}-{$widget->number}-classes'>CSS类</label>n"; $row .= "t<select name='widget-{$widget->id_base}[{$widget->number}][classes]' id='widget-{$widget->id_base}-{$widget->number}-classes' class='widefat'>"; foreach( $myclass as $key => $class ) { $selected = null; if( $class_prefix.$key == $instance['classes'] ) $selected = 'selected = "selected"'; $row .= "t<option value='$class_prefix$key' $selected>$class</value>n"; } $row .= "</select>n"; echo $row; return $instance; } add_filter('widget_form_callback', 'zm_widget_form_extend', 10, 2);   function zm_widget_update( $instance, $new_instance ) { $instance['classes'] = $new_instance['classes']; $instance['custom_id'] = $new_instance['custom_id']; return $instance; } add_filter( 'widget_update_callback', 'zm_widget_update', 10, 2 );   function zm_dynamic_sidebar_params( $params ) { global $wp_registered_widgets; $widget_id  = $params[0]['widget_id']; $widget_obj = $wp_registered_widgets[$widget_id]; $widget_opt = get_option($widget_obj['callback'][0]->option_name); $widget_num = $widget_obj['params'][0]['number'];   if ( isset( $widget_opt[$widget_num]['classes'] ) && !empty( $widget_opt[$widget_num]['classes'] ) ) $params[0]['before_widget'] = preg_replace( '/class="/', "class="{$widget_opt[$widget_num]['classes']} ", $params[0]['before_widget'], 1 ); if ( isset($widget_opt[$widget_num]['custom_id']) && !empty($widget_opt[$widget_num]['custom_id']) ) $params[0]['before_widget'] = preg_replace( '/id=".*?"/', "id="{$widget_opt[$widget_num]['custom_id']}"", $params[0]['before_widget'], 1 ); return $params; } add_filter( 'dynamic_sidebar_params', 'zm_dynamic_sidebar_params' );

代码中预设了CSS类名称，可能使用更方便些。

缺点：添加的选项位置在其它小工具选项的上面，需要改进一下。