API:
http://mp.weixin.qq.com/wiki/10/0234e39a2025342c17a7d23595c6b40a.html
https://pay.weixin.qq.com/wiki/doc/api/app/app.php?chapter=8_5
<xml>
<return_code><![CDATA[SUCCESS]]></return_code> <return_msg><![CDATA[OK]]></return_msg> <appid><![CDATA[wx8829a1d4469724d1]]></appid> <mch_id><![CDATA[1349331001]]></mch_id> <nonce_str><![CDATA[UxIFEGwNjILgAnNe]]></nonce_str> <sign><![CDATA[501222DDC31C0FA85D026C6175225A65]]></sign> <result_code><![CDATA[SUCCESS]]></result_code> <prepay_id><![CDATA[wx20160601022421f8a19c0a140557189565]]></prepay_id> <trade_type><![CDATA[APP]]></trade_type> </xml>
<xml> <appid><![CDATA[wx8829a1d4469724d1]]></appid> <bank_type><![CDATA[CFT]]></bank_type> <cash_fee><![CDATA[1]]></cash_fee> <fee_type><![CDATA[CNY]]></fee_type> <is_subscribe><![CDATA[N]]></is_subscribe> <mch_id><![CDATA[1349331001]]></mch_id> <nonce_str><![CDATA[0b234a4d3ffc45eb9e13db98cf3615c6]]></nonce_str> <openid><![CDATA[o8Bxqv_y-LnW4C58z2ZEQ8WJBr9Q]]></openid> <out_trade_no><![CDATA[R160601163348767e3845f9554]]></out_trade_no> <result_code><![CDATA[SUCCESS]]></result_code> <return_code><![CDATA[SUCCESS]]></return_code> <sign><![CDATA[31942DCD0895493C6E346F9F9A7AF18A]]></sign> <time_end><![CDATA[20160601163358]]></time_end> <total_fee>1</total_fee> <trade_type><![CDATA[APP]]></trade_type> <transaction_id><![CDATA[4007922001201606016612115749]]></transaction_id> </xml>