Helper.php

<?php
class Helper extends CController
{
       public static function truncate_utf8_string($string, $length, $etc = '...')
       {
           $result = '';
           $string = html_entity_decode(trim(strip_tags($string)), ENT_QUOTES, 'UTF-8');
           $strlen = strlen($string);
           for ($i = 0; (($i < $strlen) && ($length > 0)); $i++)
               {
               if ($number = strpos(str_pad(decbin(ord(substr($string, $i, 1))), 8, '0', STR_PAD_LEFT), '0'))
                       {
                   if ($length < 1.0)
                               {
                       break;
                   }
                   $result .= substr($string, $i, $number);
                   $length -= 1.0;
                   $i += $number - 1;
               }
                       else
                       {
                   $result .= substr($string, $i, 1);
                   $length -= 0.5;
               }
           }
           $result = htmlspecialchars($result, ENT_QUOTES, 'UTF-8');
           if ($i < $strlen)
               {
                       $result .= $etc;
           }
           return $result;
       }
}

将Helper.php放进protected\components文件夹下。

使用方法：

Helper::truncate_utf8_string($content,20,false);  //不显示省略号
Helper::truncate_utf8_string($content,20); //显示省略号