Question

 要实现在WooCommerce » Settings » Pages下添加自定义选项，例如添加一个选择产品分类的功能，如下图所示

代码如下

add_filter( 'woocommerce_page_settings', 'wc_multi_country_fields' );        
add_action( 'woocommerce_admin_field_single_select_category', 'wc_single_select_category' );
add_action( 'woocommerce_update_option', 'wc_save_single_select_category' );

function wc_multi_country_fields( $settings ){
	$new = array();
	foreach( $settings as $setting ){
		if( $setting['id'] == 'woocommerce_shop_page_id' ){
			$new[] = $setting;
			$new[] = array(
				'title' => __('Base category', 'venus'),
				'desc' => __('Select the base category', 'venus'),
				'id' => 'woocommerce_base_category_page_id',
				'type' => 'single_select_category',
				'default' => '',
				'class' => 'chosen_select_nostd',
				'css' => 'min-width:300px;',
				'desc_tip' => true
			);
			
		} else {
			$new[] = $setting;
		}
	}
	return $new;
}
	
	
function wc_single_select_category( $value ){
	global $woocommerce;
	$tip = '<img class="help_tip" data-tip="' . esc_attr( $value['desc'] ) . '" src="' . $woocommerce->plugin_url() . '/assets/images/help.png" height="16" width="16" />';
	$args = array(
		'name' => $value['id'],
		'id' => $value['id'],
		'orderby' => 'name',
		'order' => 'ASC',
		'show_option_none' => ' ',
		'class' => $value['class'],
		'echo' => false,
		'hide_empty' => false,
		'taxonomy' => 'product_cat',
		'selected' => absint(woocommerce_settings_get_option($value['id']))
	);

	if (isset($value['args']))
		$args = wp_parse_args($value['args'], $args);
	?><tr valign="top" class="single_select_page">
		<th scope="row" class="titledesc"><?php echo esc_html($value['title']) ?> <?php echo $tip; ?></th>
		<td class="forminp">
			<?php echo str_replace(' id=', " data-placeholder='" . __('Select a category&hellip;', 'venus') . "' style='" . $value['css'] . "' class='" . $value['class'] . "' id=", wp_dropdown_categories($args)); ?> <?php echo $description; ?>
		</td>
	  </tr><?php
}  

function wc_save_single_select_category( $value ){
	if( $value['type'] == 'single_select_category'){
		if ( isset( $_POST[$value['id']] ) ) {
			$option_value = woocommerce_clean( stripslashes( $_POST[ $value['id'] ] ) );
		} else {
			$option_value = '';
		}
		update_option( $value['id'], $option_value );
	}
}

调用所保存的category方法

WooCommerce的产品分类是一个custom taxonomy，slug是product_cat

获取产品分类ID

woocommerce_get_page_id('base_category')

获取产品分类链接

get_term_link( (int)woocommerce_get_page_id('base_category'), 'product_cat' )