/**
* 空白字符替换
* @param string $content 内容
* @param string $len 截取长度
* @param string $encode 编码
* @return string
*/
function mbStrReplace($content,$len=0,$encode='utf-8',$htmltags=true) {
$str = trim($content);
if($htmltags) $str = strip_tags($str);
$str = preg_replace('/[\n|\r|\t]+/', '', $str);
$str = preg_replace("/(\s|\ \;| |\xc2\xa0)/",'',$str);//借鉴:http://bbs.phpchina.com/thread-209008-1-1.html
if($len > 0)
return mb_substr($str,0,$len,$encode);
else
return $str;
}