Android BatteryManager仅返回1

Question

当我的重复警报广播器被调用时,我试图读取Android电池的状态我有以下设置:

public class RepeatingAlarm extends BroadcastReceiver {

    @Override       
    public void onReceive(Context context, Intent intent)
    {

            // Acquire the make of the device
            final String PhoneModel = android.os.Build.MODEL;
            final String AndroidVersion = android.os.Build.VERSION.RELEASE;

            // Grab the battery information
            int level = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
            int scale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1);
            final float batteryPct = level / (float)scale; 
    }

}

但我不明白它为什么要回归那个batteryPct = 1.这里有什么我想念的吗？我添加了基于Android Google页面的正确权限,但这似乎没有帮助.

Answer 1

你得到-1了两个level和scale.那是因为你可能试图ACTION_BATTERY_CHANGED在清单中广播.

ACTION_BATTERY_CHANGED是一个粘性意图,你不能在清单中注册接收器.请尝试以下方法

 Intent i = new ContextWrapper(applicationContext).registerReceiver(null, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
 // now you can get the level and scale from this intent variable
int level = i.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
int scale = i.getIntExtra(BatteryManager.EXTRA_SCALE, -1);

float battPct = level/(float)scale;

你不会为这个意图设置一个接收器,只需使用上面提到的方式,无论你想使用它.