设置字符集后如何还乱码

$temp = '判断是否有中文';<br />
//判断是否有中文<br />
if(preg_match('/[\x81-\xfe][\x40-\xfe]/',$temp)){<br />
  mb_internal_encoding("gbk");<br />
}else {<br />
  mb_internal_encoding("utf-8");<br />
}<br />
$len = mb_strlen($temp);<br />
$t = '';<br />
for($k=0; $k<$len; $k++){<br />
  if($k>1) {<br />
    $t .= '*';<br />
  }else {<br />
   $t .= mb_substr($temp, $k, 1);<br />
  }<br />
}<br />
echo $t;

$load_list =array(<br />
  array('user_name' => 'xiaodg'),<br />
  array('user_name' => 'x42466'),<br />
  array('user_name' => 'etea'),<br />
  array('user_name' => 'na0617'),<br />
  array('user_name' => 'kimo'),<br />
  array('user_name' => '留影'),<br />
  array('user_name' => 'vian22'),<br />
  array('user_name' => 'qingyu'),<br />
  array('user_name' => 'jiangliman'),<br />
  array('user_name' => 'xiaobu'),<br />
  array('user_name' => 'xiaobu'),<br />
  array('user_name' => 'hfa818'),<br />
);<br />
<br />
foreach($load_list as $k=>&$v){<br />
  $temp=$v['user_name'];<br />
<br />
  //判断是否有中文<br />
  if(preg_match('/[\x81-\xfe][\x40-\xfe]/',$temp)){<br />
    mb_internal_encoding("gbk");<br />
  }else {<br />
    mb_internal_encoding("utf-8");<br />
  }<br />
  $len = mb_strlen($temp);<br />
  $t = '';<br />
  for($k=0; $k<$len; $k++){<br />
    if($k>2) {<br />
      $t .= '*';<br />
    }else {<br />
      $t .= mb_substr($temp, $k, 1);<br />
    }<br />
  }<br />
  $v['user_name'] = $t;<br />
}<br />
print_r($load_list);

Array<br>
(<br>
    [0] =&gt; Array<br>
        (<br>
            [user_name] =&gt; xia***<br>
        )<br><br>
    [1] =&gt; Array<br>
        (<br>
            [user_name] =&gt; x42***<br>
        )<br><br>
    [2] =&gt; Array<br>
        (<br>
            [user_name] =&gt; ete*<br>
        )<br><br>
    [3] =&gt; Array<br>
        (<br>
            [user_name] =&gt; na0***<br>
        )<br><br>
    [4] =&gt; Array<br>
        (<br>
            [user_name] =&gt; kim*<br>
        )<br><br>
    [5] =&gt; Array<br>
        (<br>
            [user_name] =&gt; 留影<br>
        )<br><br>
    [6] =&gt; Array<br>
        (<br>
            [user_name] =&gt; via***<br>
        )<br><br>
    [7] =&gt; Array<br>
        (<br>
            [user_name] =&gt; qin***<br>
        )<br><br>
    [8] =&gt; Array <div class="clear"></div>