检测usb是否连接pc

IntentFilter ifilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);Intent batteryStatus = context.registerReceiver(null, ifilter);int status = batteryStatus.getIntExtra(BatteryManager.EXTRA_STATUS, -1);boolean isCharging = status == BatteryManager.BATTERY_STATUS_CHARGING ||                 status == BatteryManager.BATTERY_STATUS_FULL;int chargePlug = batteryStatus.getIntExtra(BatteryManager.EXTRA_PLUGGED, -1);boolean usbCharge = chargePlug == BatteryManager.BATTERY_PLUGGED_USB;boolean acCharge = chargePlug == BatteryManager.BATTERY_PLUGGED_AC; isCharging 和 usbCharge =true连接到pc

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