Android

PhoneStateListener在实时获取手机信号强度，真机测试signalStrength.getGsm

想用PhoneStateListener实时获取手机信号强度，三星s4真机测试时onSignalStrengthsChanged里得到的signalStrength一直是固定值（SignalStrength: 99 0 -120 -160 -120 -1 -1 99 2147483647 2147483647 2147483647 2147483647 -8……