入参：<xml>

<appid>wx235a1d0cc******</appid>

<mch_id>16044*****</mch_id>

<nonce_str>160679030183241119</nonce_str>

<out_trade_no>163541635</out_trade_no>

<sing>9325F0B5B0B923D8EF6199C86F30127D</sing>

<sign_type>MD5</sign_type>

</xml>

还缺啥呢