关于ios BLE在后台自动重连的问题 

找到一个国外网站是这么描述的

Re: How to make the BTLE APP to auto connect with BTLE device when iPhone4S power on ^沿途见识

When backgrounding, you can still scan and connect to a LE peripheral.  You can scan for peripherals using scanForPeripheralsWithSerives by stating what service you are looking for in a Peripheral.  You cannot do a general scan without stating at least one service in the passed dictionary.  If you have a CFUUIDRef from a previous connection, you can call retrievePeripherals with the CFUUIDRef.  Your delegate will receive a call to didRetrievePeripherals with a CBPeripheral.  With the CBPeripheral you can then connect using connectPeripheral.