Customize the WordPress Tag Cloud Widget

functions.php

<?php
// the hook to custom tag widget, put in you `functions.php`
function my_tag_cloud_filter($args = array()) {
  $args['smallest'] = 12; //最小字号
  $args['largest'] = 12; //最大字号
  $args['unit'] = 'px'; //字体单位 px，pt，em
  $args['number'] = 20; //调用数量
  $args['orderby'] = 'count'; //按何值排序
  $args['order'] = 'RAND'; //排序方式
  // for more check here: http://codex.wordpress.org/Function_Reference/wp_tag_cloud
  return $args;
}
add_filter('widget_tag_cloud_args', 'my_tag_cloud_filter', 10);
?>