我怎样才能电池电量和状态（插入，放电，充电等）？我研究了开发文档，我发现一个BatteryManager类。但它不包含任何方法，只要常量。如何我甚至用它？

Answer 1:

这里是解释如何获得电池信息的代码示例。

概括起来讲，对于广播接收机ACTION_BATTERY_CHANGED意图建立动态的，因为它无法通过清单中声明组件接收，仅通过用显式登记为它Context.registerReceiver()

public class Main extends Activity {
  private TextView batteryTxt;
  private BroadcastReceiver mBatInfoReceiver = new BroadcastReceiver(){
    @Override
    public void onReceive(Context ctxt, Intent intent) {
      int level = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, 0);
      batteryTxt.setText(String.valueOf(level) + "%");
    }
  };

  @Override
  public void onCreate(Bundle b) {
    super.onCreate(b);
    setContentView(R.layout.main);
    batteryTxt = (TextView) this.findViewById(R.id.batteryTxt);
    this.registerReceiver(this.mBatInfoReceiver, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
  }
}

Answer 2:

由于API 21日已经可以使用以下方法来获得当前电池电量为百分比：

BatteryManager bm = (BatteryManager)getSystemService(BATTERY_SERVICE);
int batLevel = bm.getIntProperty(BatteryManager.BATTERY_PROPERTY_CAPACITY);

Answer 3:

基于官方Android文档，您可以使用此方法在助手或的Util类来获得当前电池百分比：

public static int getBatteryPercentage(Context context) {

    IntentFilter iFilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
    Intent batteryStatus = context.registerReceiver(null, iFilter);

    int level = batteryStatus != null ? batteryStatus.getIntExtra(BatteryManager.EXTRA_LEVEL, -1) : -1;
    int scale = batteryStatus != null ? batteryStatus.getIntExtra(BatteryManager.EXTRA_SCALE, -1) : -1;

    float batteryPct = level / (float) scale;

    return (int) (batteryPct * 100);
}

Answer 4:

您没有使用粘性意向登记的实际广播接收器作为Android的BatteryManager：

IntentFilter ifilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
Intent batteryStatus = registerReceiver(null, ifilter);

int level = batteryStatus.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
int scale = batteryStatus.getIntExtra(BatteryManager.EXTRA_SCALE, -1);

float batteryPct = level / (float)scale;

return (int)(batteryPct*100);

这是从官方文档上的https://developer.android.com/training/monitoring-device-state/battery-monitoring.html 。

Answer 5:

你可以用它来获得剩余百分比收取费用。

private void batteryLevel() {
        BroadcastReceiver batteryLevelReceiver = new BroadcastReceiver() {
            public void onReceive(Context context, Intent intent) {
                context.unregisterReceiver(this);
                int rawlevel = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
                int scale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1);
                int level = -1;
                if (rawlevel >= 0 && scale > 0) {
                    level = (rawlevel * 100) / scale;
                }
                batterLevel.setText("Battery Level Remaining: " + level + "%");
            }
        };
        IntentFilter batteryLevelFilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
        registerReceiver(batteryLevelReceiver, batteryLevelFilter);
    }

Answer 6:

试试这个功能不需要在未经许可或任何reciver

void getBattery_percentage()
{
      IntentFilter ifilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
      Intent batteryStatus = getApplicationContext().registerReceiver(null, ifilter);
      int level = batteryStatus.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
      int scale = batteryStatus.getIntExtra(BatteryManager.EXTRA_SCALE, -1);
      float batteryPct = level / (float)scale;
      float p = batteryPct * 100;

      Log.d("Battery percentage",String.valueOf(Math.round(p)));
  }

Answer 7:

一些经过研究，我发现BatteryManager.EXTRA_LEVEL。

Answer 8:

private void batteryLevel() {
        BroadcastReceiver batteryLevelReceiver = new BroadcastReceiver() {
            public void onReceive(Context context, Intent intent) {
                context.unregisterReceiver(this);
                int rawlevel = intent.getIntExtra("level", -1);
                int scale = intent.getIntExtra("scale", -1);
                int level = -1;
                if (rawlevel >= 0 && scale > 0) {
                    level = (rawlevel * 100) / scale;
                }
                mBtn.setText("Battery Level Remaining: " + level + "%");
            }
        };
        IntentFilter batteryLevelFilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
        registerReceiver(batteryLevelReceiver, batteryLevelFilter);
    }

Answer 9:

要检查我们使用BatteryManager电量百分比，下面的方法将返回电量百分比。

源链接

public static float getBatteryLevel(Context context, Intent intent) {
    Intent batteryStatus = context.registerReceiver(null,
            new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
    int batteryLevel = -1;
    int batteryScale = 1;
    if (batteryStatus != null) {
        batteryLevel = batteryStatus.getIntExtra(BatteryManager.EXTRA_LEVEL, batteryLevel);
        batteryScale = batteryStatus.getIntExtra(BatteryManager.EXTRA_SCALE, batteryScale);
    }
    return batteryLevel / (float) batteryScale * 100;
}

Answer 10:

在官方的文档一个错误，则必须使用双，而不是浮动。因为0.53F * 100F = 52F

int level = batteryStatus != null ? 
batteryStatus.getIntExtra(BatteryManager.EXTRA_LEVEL, -1) : -1; int scale = 
batteryStatus != null ? batteryStatus.getIntExtra(BatteryManager.EXTRA_SCALE, -1) : -1; 
double batteryPct = (double) level / (double) scale; int percent = (int) (batteryPct * 100D);

文章来源: Get battery level and state in Android