json变换数组时中文为NULL解决方案

json转换数组时中文为NULL解决方案
$json='[{"ZtdID":"100000","ZtdNo":"001 ","ZtdName":"1号店 ","Address":"XX市ZZ区YY路01号铺 ","Remark":"","AreaID":"01","ZtdTel":"0000-8888888","ZtdContact":"张三"},{"ZtdID":"100001","ZtdNo":"002 ","ZtdName":"1号店 ","Address":"XX市ZZ区YY路01号铺 ","Remark":"","AreaID":"01","ZtdTel":"0000-8888888","ZtdContact":"李三"}]';
var_dump(json_decode($json,true));

?>
输出为NULL
经仔细查看，是编码问题，求解？

------解决方案--------------------
iconv('gbk','UTF-8','我是中文要转换成json');

转吧.PHP的json 中文没有支持gbk gb2312的格式

------解决方案--------------------

$json='[{"ZtdID":"100000","ZtdNo":"001 ","ZtdName":"1号店 ","Address":"XX市ZZ区YY路01号铺 ","Remark":"","AreaID":"01","ZtdTel":"0000-8888888","ZtdContact":"张三"},{"ZtdID":"100001","ZtdNo":"002 ","ZtdName":"1号店 ","Address":"XX市ZZ区YY路01号铺 ","Remark":"","AreaID":"01","ZtdTel":"0000-8888888","ZtdContact":"李三"}]';

debug( $json );

debug( json_decode($json,true) );

------------------输出正常

[{"ZtdID":"100000","ZtdNo":"001 ","ZtdName":"1号店 ","Address":"XX市ZZ区YY路01号铺 ","Remark":"","AreaID":"01","ZtdTel":"0000-8888888","ZtdContact":"张三"},{"ZtdID":"100001","ZtdNo":"002 ","ZtdName":"1号店 ","Address":"XX市ZZ区YY路01号铺 ","Remark":"","AreaID":"01","ZtdTel":"0000-8888888","ZtdContact":"李三"}]



Array

(

    [0] => Array

        (

            [ZtdID] => 100000

            [ZtdNo] => 001 

            [ZtdName] => 1号店 

            [Address] => XX市ZZ区YY路01号铺 

            [Remark] => 

            [AreaID] => 01

            [ZtdTel] => 0000-8888888

            [ZtdContact] => 张三

        )



    [1] => Array

        (

            [ZtdID] => 100001

            [ZtdNo] => 002 

            [ZtdName] => 1号店 

            [Address] => XX市ZZ区YY路01号铺 

            [Remark] => 

            [AreaID] => 01

            [ZtdTel] => 0000-8888888

            [ZtdContact] => 李三

        )



)

------解决方案--------------------
$json='{"ZtdID":"100000","ZtdNo":"001","ZtdName":"1号店","Address":"XX市ZZ区YY路01号铺","Remark":"","AreaID":"01","ZtdTel":"0000-8888888","ZtdContact":"张三"}';