## 获取单个分类 ``` app('rpc.course')->call('apps.category.get',[$id = 1]); ``` ~~~[api] post:demo.getlist id=1 <<< Array { "jsonrpc":"2.0", "result":{         "id":1,         "grade":0,         "cid":1,         "title":"互动新绘本",         "intro":"培养阅读习惯，提升表达能力",         "vurl":"",         "onpic":"image/2018/08/14/152008\_5b7282a8436f6.jpg",         "icon":"",         "isaddr":0,         "ispower":0,         "type":2,         "state":0,         "sort":3,         "utime":"1547606918",         "ctime":"1530868921"     }, "id":"a7e9ce8948103002385e0455e71981c9" } <<< error Array ( [error] => Array ( [code] => -32602 [message] => Invalid params [data] => ) ) ~~~