php案例：将utf8的编码转换成gbk,并且正常显示

<?php
header("content-type:text/html;charset=gbk");
$string = "你好"; // UTF-8编码的字符串
$gbkString = iconv("UTF-8", "GBK",  $string); // 转为GBK编码的字符串
if (mb_check_encoding($gbkString, 'GBK')) {//检测是不是gbk格式的编码
    echo "GBK";
}

?>