====== randomOnePlayer ======

----

  * Parameters and types:
     * alive: numberplayer status (0 means dead, 1 means alive, default -1 means all players)
  * Return value and type:
    * code: numberSuccess (ErrorCode.OK) ErrorCode
    * playerid: numberplayerUin
  * The main function of this method: Randomly obtain a player
  * The specific use cases are as follows:

<code>
--Randomly select a player from all players
--Parameters: -1 all players 0 dead players 1 alive players
local result,playerid=World:randomOnePlayer(-1)
--Display in the chat box
Chat:sendSystemMsg("Randomly selected a player:"..playerid)
</code>