Android入门（52）——第七章 Android中常用的系统服务

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="comimooc.systemservicedemo"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="10" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>
<uses-permission android:name="android.permission.GET_TASKS"/>

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="comimooc.systemservicedemo.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

</manifest>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >

<Button
android:id="@+id/network"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:onClick="doClick"
android:text="判断网络是否连接" />

<Button
android:id="@+id/enableOrDisable_WIFI"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/network"
android:layout_alignRight="@+id/network"
android:layout_below="@+id/network"
android:onClick="doClick"
android:text="开关WIFI" />

<Button
android:id="@+id/getvoice"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/enableOrDisable_WIFI"
android:layout_alignRight="@+id/enableOrDisable_WIFI"
android:layout_below="@+id/enableOrDisable_WIFI"
android:onClick="doClick"
android:text="获取系统的音量" />

<Button
android:id="@+id/getPackagename"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/getvoice"
android:layout_alignRight="@+id/getvoice"
android:layout_below="@+id/getvoice"
android:onClick="doClick"
android:text="获取当前进程包名" />

</RelativeLayout>

package comimooc.systemservicedemo;

import android.app.Activity;
import android.app.ActivityManager;
import android.content.Context;
import android.media.AudioManager;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.net.wifi.WifiManager;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

// 获取系统的服务。
LayoutInflater inflater = (LayoutInflater) MainActivity.this
.getSystemService(LAYOUT_INFLATER_SERVICE);
// 然后绑定一个布局转化为一个View。
View view = inflater.inflate(R.layout.activity_main, null);
// 这里不只是可以添加布局文件，也可以添加View的。
setContentView(view);
}

public void doClick(View v) {
switch (v.getId()) {
// 判断网络是否连接：
case R.id.network:
if (isNetWorkConnected(MainActivity.this) == true) {
Toast.makeText(MainActivity.this, "网络已经打开", Toast.LENGTH_SHORT)
.show();
} else {
Toast.makeText(MainActivity.this, "网络未连接", Toast.LENGTH_SHORT)
.show();
}
break;
// 判断Wifi是否连接：
case R.id.enableOrDisable_WIFI:
WifiManager wifiManager = (WifiManager) MainActivity.this
.getSystemService(WIFI_SERVICE);
if (wifiManager.isWifiEnabled()) {
wifiManager.setWifiEnabled(false);
Toast.makeText(MainActivity.this, "WIFI已经关闭",
Toast.LENGTH_SHORT).show();
} else {
wifiManager.setWifiEnabled(true);
Toast.makeText(MainActivity.this, "WIFI已经打开",
Toast.LENGTH_SHORT).show();
}

break;
// 获取系统音量：
case R.id.getvoice:
AudioManager mAudioManager = (AudioManager) MainActivity.this
.getSystemService(AUDIO_SERVICE);
int max = mAudioManager
.getStreamMaxVolume(AudioManager.STREAM_SYSTEM);
int current = mAudioManager
.getStreamVolume(AudioManager.STREAM_RING);
Toast.makeText(MainActivity.this,
"系统的最大音量为：" + max + ",当前音量是：" + current, Toast.LENGTH_SHORT)
.show();
break;
// 获取程序包包名：
case R.id.getPackagename:
ActivityManager activityManager = (ActivityManager) MainActivity.this
.getSystemService(ACTIVITY_SERVICE);
String packageName = activityManager.getRunningTasks(1).get(0).topActivity
.getPackageName();
Toast.makeText(MainActivity.this, "当前运行的Activity包名：" + packageName,
Toast.LENGTH_SHORT).show();
break;
}
}

/*
* 判断网络是否连接：
* */
public boolean isNetWorkConnected(Context context) {
if (context != null) {
// 获取网络连接对象ConnectivityManager
ConnectivityManager mConnectivityManager = (ConnectivityManager) context
.getSystemService(CONNECTIVITY_SERVICE);
// 获取当前网络信息
NetworkInfo mNetWorkInfo = mConnectivityManager
.getActiveNetworkInfo();
if (mNetWorkInfo != null) {
// 返回网络连接状态
return mNetWorkInfo.isAvailable();
}
}
return false;
}
}