PHP-json_decode 返回NULL

Question

我在调试接口的时候，接收对方传来的json，发现用json_decode直接转化为数组会返回NULL值。

$response = '{"retcode":"0","retmsg":"OK","cre_id_enc":"","cre_type":"","fee_type":"1","listid":"1221085301201410240000001024","out_trade_no":"201410246763831","partner":"1221085301","pay_fee":"0","sign":"PTamaux2BjkynA00cASKJ6Nd3QwFSBP44TKSqmmdCdx2Fx2B0o8ViSt3fp5vQr0Fc73U42NhtImfnHzbynoUjURiNLW5O4hI61xkGx2F97JRPRE0nHuvtAumqXfbVCsLveugE52HRZsJvm3EG7pL6GlhYf8ng6qxiUrDyn89PFVZ04Wd8Gkx3D","total_fee":"1000000","unfreeze_fee":"1000000","user_name_enc":""}';

Answer 1

解决了，答案在这里 http://www.yunxiu.org/wenda/39/json_decode-返回null怎么解决？
这种十六进制的ASCII字符需要转义。