Question

我希望从一项活动到另一项活动获得电池电量百分比。

我无法从“BroadcastReciver”获取它，也无法从文本视图中提取它。

这是我的广播接收者：

private BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {

        int scale = intent.getIntExtra(BatteryManager.EXTRA_SCALE,-1);      

        int level = intent.getIntExtra(BatteryManager.EXTRA_LEVEL,-1);     

        float percentage = level/ (float) scale;                          

        int mProgressStatus = (int)((percentage)*100);                       

        bl.setText("" + mProgressStatus + "%");        

    }
};

这就是我提取它的方式：

public int batt(){

        String input = bl.getText().toString();
        input = input.replace( "\n", "" );
        input = input.replace( " ", "" );
        int total = getValue(input);


        return total;
    }

    public int getValue(String line){
        int  value = 0;

        if( line.contains( "+" ) ) {
            String[] lines = line.split( "\\+" );
            value += getValue( lines[0] );

            for( int i = 1; i < lines.length; i++ )
                value += getValue( lines[i] );

            return value;
        }

        if( line.contains( "-" ) ) {
            String[] lines = line.split( "\\-" );
            value += getValue( lines[0] );

            for( int i = 1; i < lines.length; i++ )
                value -= getValue( lines[i] );

            return value;
        }

        if( line.contains( "*" ) ) {
            String[] lines = line.split( "\\*" );
            value += getValue( lines[0] );

            for( int i = 1; i < lines.length; i++ )
                value *= getValue( lines[i] );

            return value;
        }

        if( line.contains( "/" ) ) {
            String[] lines = line.split( "\\/" );
            value += getValue( lines[0] );

            for( int i = 1; i < lines.length; i++ )
                value /= getValue( lines[i] );

            return value;
        }

        return Integer.parseInt( line );
    }

Answer 1

Android 2.0或更高，您可以对BatterLevelActivity类的电池电量方法进行以下更改：

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);
    }

有关整个项目的更多详情：battery-level-and-state。

或者您只需检查上述内容是否有效，SirDarius给出答案，动态设置ACTION_BATTERY_CHANGED意图的广播接收器。

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

要将数据从一个活动传输到另一个活动，您可以执行此操作

Intent intent = new Intent(getBaseContext(), NewActivity.class);
intent.putExtra("BATTERY_LEVEL", mProgressStatus);
startActivity(intent);

然后在新活动中

String s = getIntent().getStringExtra("BATTERY_LEVEL");

OR
您可以使用sharedpreferences
您可以在此处详细了解共享偏好设置https://developer.android.com/reference/android/content/SharedPreferences.html

如何将电池百分比从一个活动转移到另一个活动

2 个答案: