android 充电广播

Android中充电状态的改变可以通过广播来监听。具体来说，可以使用`Intent.ACTION_BATTERY_CHANGED`广播和`BatteryManager`类来获取充电状态信息。以下是一个示例代码：

public class ChargingReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        int status = intent.getIntExtra(BatteryManager.EXTRA_STATUS, -1);
        boolean isCharging = status == BatteryManager.BATTERY_STATUS_CHARGING ||
                status == BatteryManager.BATTERY_STATUS_FULL;
        int chargePlug = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, -1);
        boolean usbCharge = chargePlug == BatteryManager.BATTERY_PLUGGED_USB;
        boolean acCharge = chargePlug == BatteryManager.BATTERY_PLUGGED_AC;

        if (isCharging) {
            if (usbCharge) {
                // USB 充电
            } else if (acCharge) {
                // 电源充电
            }
        } else {
            // 未充电
        }
    }
}

要监听充电状态，需要在`AndroidManifest.xml`文件中注册广播接收器：

<receiver
    android:name=".ChargingReceiver">
    <intent-filter>
        <action android:name="android.intent.action.ACTION_POWER_CONNECTED"/>
        <action android:name="android.intent.action.ACTION_POWER_DISCONNECTED"/>
    </intent-filter>
</receiver>

当充电状态发生变化时，`onReceive()`方法将被调用。