Question

我想开发一个Android应用程序，监控http://developer.android.com/training/monitoring-device-state/battery-monitoring.html#CurrentLevel

中指定的电池电量和充电状态

但是，我不知道从哪里开始以及放置本教程中提到的intent过滤器和广播接收器的位置。

请帮助我们如何开始使用提到的意图过滤器：

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

Answer 1

使用以下代码

import android.os.BatteryManager;
import android.os.Bundle;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.view.Menu;
import android.widget.TextView;

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

/* @Override*/
protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_main);
     batteryPercent = (TextView) this.findViewById(R.id.textview);
     getBatteryPercentage();
}

//    @Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
}

}

使用以下代码检查设备是否已插入

public static boolean isPlugged(Context context) {
boolean isPlugged= false;
Intent intent = context.registerReceiver(null, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
int plugged = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, -1);
isPlugged = plugged == BatteryManager.BATTERY_PLUGGED_AC || plugged == BatteryManager.BATTERY_PLUGGED_USB;
if (VERSION.SDK_INT > VERSION_CODES.JELLY_BEAN) {
    isPlugged = isPlugged || plugged == BatteryManager.BATTERY_PLUGGED_WIRELESS;
}
return isPlugged;
}

Answer 2

package com.example.govind.batterystate;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.res.Resources;
import android.os.BatteryManager;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ImageView;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    private TextView batteryPercent;
    private void getBatteryPercentage() {
        BroadcastReceiver batteryLevelReceiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                context.unregisterReceiver(this);
                int currentLevel = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
                int scale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1);
                int level = -1;
                if (currentLevel >= 0 && scale > 0) {
                    level = (currentLevel * 100) / scale;
                }
                batteryPercent.setText("Status: " + level + "%");
            }
        };
        IntentFilter batteryLevelFilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
        registerReceiver(batteryLevelReceiver, batteryLevelFilter);
    }


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        batteryPercent = (TextView) this.findViewById(R.id.statusValue);
        getBatteryPercentage();
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });
    }

    //Plugged In or Not

    public static boolean isPlugged(Context context) {
        boolean isPlugged= false;
        Intent intent = context.registerReceiver(null, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
        int plugged = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, -1);
        isPlugged = plugged == BatteryManager.BATTERY_PLUGGED_AC || plugged == BatteryManager.BATTERY_PLUGGED_USB;
        //if (VERSION.SDK_INT > VERSION_CODES.JELLY_BEAN) {
          //  isPlugged = isPlugged || plugged == BatteryManager.BATTERY_PLUGGED_WIRELESS;
        //}
        return isPlugged;


    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }


}

Virtual Machine's screen

针对电池状态的Android应用开发

2 个答案: