如何进行节目下发？

要进行节目下发，可以发送以下命令：
```
{"type":"commandXixunPlayer","_id":"28dc5b76-51c9-11e9-9b24-4ccc6a95f6dc","command":{"_type":"PlayXixunTask","id":"28dd5a80-51c9-11e9-9b24-4ccc6a95f6dc","preDownloadURL":"http://8.136.4.199/upload/","notificationURL":"http://192.168.2.105:8083/getJSON","task":{"_id":"28dd55c6-51c9-11e9-9b24-4ccc6a95f6dc","name":"图片节目 test","items":[{"_id":"7111bd0f-edba-4db6-8bd4-f5071d79a265","_program":{"_id":"28dd2786-51c9-11e9-9b24-4ccc6a95f6dc","totalSize":55066,"name":"图片节目 test","width":128,"height":256,"__v":0,"layers":[{"repeat":false,"sources":[{"maxPlayTime":31,"_type":"Image","md5":"b9bcfa191b1ddb4bdfc6a6057dc534f6","name":"5s.jpg","mime":"image/jpeg","size":55066,"fileExt":".jpg","id":"5s.jpg","playTime":0,"timeSpan":10,"left":0,"top":0,"width":128,"height":256,"entryEffect":"None","exitEffect":"None","entryEffectTimeSpan":0,"exitEffectTimeSpan":0}]}]},"priority":0,"repeatTimes":1,"version":0,"schedules":[{"filterType":"None","timeType":"Range","startTime":"00:00","endTime":"23:59","dateType":"All"}]}]}}}
```
通过发送这个命令，可以将指定的节目下发到智慧灯杆上进行播放。