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Android Service练习（下） [复制链接]

云少嘎嘎嘎

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发表于 2011-12-20 09:44 |只看该作者 |倒序浏览

继续接上文。点击主界面上的“bind启动Service”后，进入第二个副界面。第二个副界面我使用ListView来实现和用户的交互，并且能实时获取服务中提供的数值将其显示在界面上。该界面的布局文件为bind.xml其内容如下：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<RelativeLayout android:id="@+id/RelativeLayout02"
android:paddingTop="21.0px"
android:paddingBottom="10.0px"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="15.0px"
android:layout_marginTop="62.0px"
android:layout_marginRight="15.0px">
<ListView android:id="@+id/listView1"
android:layout_height="wrap_content"
android:layout_width="fill_parent">
</ListView>
<TextView android:id="@+id/bindtext"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/listView1"
android:gravity="center"
/>
</RelativeLayout>
</LinearLayout>

在这里我使用了RelativeLayout布局，因为如果还用LinerLayout布局的话就不能正常显示TextView了。界面的类我命名为bindStart.java，在这里碰到了难题，就是如何更新显示的内容。我的想法就是使用一个线程，每一秒中从Service那里获取数字并显示出来。但是系统却频频报错。向别人提问后才知道对于Activity界面的更新只有主线程才可以，别的线程一律不允许碰。那么要告诉主线程更新显示怎么办呢？这就要用到Handler类，Handler类可以说是用来实现线程间的通信。通过一个线程获取数据并发信息给主线程，主线程收到信息后按要求更新显示的内容。类的内容为：

package com.test;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class bindStart extends Activity {
private final static String TAG="bindStart";
ListView listView;
TextView textView;
ArrayAdapter adapter;
bindService bindservice;
int num;
int act;
//更新显示用的线程
fresh freshtext;
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.bind);
listView=(ListView)findViewById(R.id.listView1);
textView = (TextView)findViewById(R.id.bindtext);
textView.setText(num+"");
//设定list的背景色，否则显示不出来
int mycolor=getResources().getColor(R.color.bachgroud);
listView.setBackgroundColor(mycolor);
//获得显示的内容
adapter=ArrayAdapter.createFromResource(this.getApplicationContext(), R.array.actions,
android.R.layout.simple_spinner_dropdown_item);
listView.setAdapter(adapter);
freshtext=new fresh();
//开始bind
Log.d(TAG, "connecting.....");
Intent intent = new Intent("com.test.bindService");
bindService(intent, sc, Context.BIND_AUTO_CREATE);
//对list添加点击事件响应
listView.setOnItemClickListener(new OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
switch(position){
case 0:
Toast.makeText(getApplicationContext(), "啥也不做", Toast.LENGTH_SHORT).show();
break;
case 1:
act=1;
start(act);
Toast.makeText(getApplicationContext(), "启动服务", Toast.LENGTH_SHORT).show();
break;
case 2:
act=2;
start(act);
Toast.makeText(getApplicationContext(), "暂停服务", Toast.LENGTH_SHORT).show();
break;
case 3:
act=3;
start(act);
stop();
break;
}
}
});
}
private void start(int act) {
Intent intent=new Intent("com.test.bindService");
Bundle bundle=new Bundle();
bundle.putInt("act", act);
intent.putExtras(bundle);
startService(intent);
Log.v("start","startbindservice");
//如果当前有更新线程在运行，首先结束它
if(freshtext.running){
freshtext.running=false;
}
//重新启动更新线程
freshtext=new fresh();
freshtext.running=true;
new Thread(freshtext).start();
}
public void stop() {
if(freshtext.running){
freshtext.running=false;
}
this.unbindService(sc);
this.finish();
}
class fresh implements Runnable{
Boolean running=false;
@Override
public void run() {
while(running){
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
//获取服务中产生的数字
num =bindservice.get();
//通过handler发消息给主线程，更新显示的内容
Message msg=new Message();
msg.what=1;
h.sendMessage(msg);
Log.d(TAG,"num is :"+num);
}
}
}
ServiceConnection sc=new ServiceConnection(){
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
bindservice=((bindService.myBinder)service).getService();
Log.d(TAG, "in onServiceConnected");
}
@Override
public void onServiceDisconnected(ComponentName name) {
bindservice=null;
}
};
/*
* 主线程处理收到的信息
*/
Handler h=new Handler(){
public void handleMessage(Message msg){
Log.d(TAG,"msg is "+msg.toString());
switch(msg.what){
case 1:
textView.setText(num+"");
break;
}
}
};
}

接下来当然是服务类了，没有什么特别之处，还是每秒钟对变量加一。

package com.test;
import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.Bundle;
import android.os.IBinder;
import android.util.Log;
public class bindService extends Service {
private final static String TAG="bindService";
private IBinder binder=new myBinder();
private int n=0;
private count thread;
@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return binder;
}
public class myBinder extends Binder{
public bindService getService(){
return bindService.this;
}
}
public int get(){
return n;
}
public void onCreate(){
super.onCreate();
Log.d(TAG,"onCreate");
thread=new count();
}
public void onStart(Intent intent, int startId){
Log.d(TAG,"onstart");
if(intent!=null){
Bundle budle=intent.getExtras();
int act=budle.getInt("act");
switch(act){
case 1:
start();
break;
case 2:
stop();
break;

                 case 3:
                    finsish();

            }
        }
    }

    private void finsish() {
        thread.setPause(true);
        stopSelf();

    }

class count extends Thread{
private boolean pause=false;
public void setPause(boolean tof){
pause=tof;
}
public boolean getPauseStatues(){
return pause;
}
public void run(){
while(!pause){
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
n++;
Log.d(TAG,"n is:"+n);
}
}
}
private void stop() {
thread.setPause(true);
}
private void start() {
stop();
if(thread.getPauseStatues()==true){
thread=new count();
thread.setPause(false);
}
thread.start();
Log.d(TAG,String.valueOf(thread.getPauseStatues()));
}
}

该界面的显示如下图所示：最下面的数字每秒钟会更新一次。

最后就是远程Service了，使用了AIDL接口实现Activity和Service之间的通信，在这个界面中我使用单选按钮来和用户就行交互。布局文件为remote.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<RadioGroup
android:id="@+id/radioGroup1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center">
<RadioButton
android:layout_width="wrap_content"
android:id="@+id/radio0"
android:layout_height="wrap_content"
android:text="@string/do_nothing"
android:checked="true">
</RadioButton>
<RadioButton
android:layout_width="wrap_content"
android:id="@+id/radio1"
android:layout_height="wrap_content"
android:text="@string/start">
</RadioButton>
<RadioButton
android:layout_width="wrap_content"
android:id="@+id/radio2"
android:layout_height="wrap_content"
android:text="@string/pause">
</RadioButton>
<RadioButton
android:layout_width="wrap_content"
android:id="@+id/radio3"
android:layout_height="wrap_content"
android:text="@string/stop">
</RadioButton>
</RadioGroup>
<TextView
android:id="@+id/radioText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center">
</TextView>
</LinearLayout>

既然使用到了AIDL当然要创建AIDL文件了，AIDL文件命名为IremoteService.aidl

package com.test;
interface IremoteService{
String getTime();
void stop();
}

下面是界面的代码，在里面同样通过一个线程发消息给主线程，实时更新显示的内容，这次显示的内容为系统时间，由Service端负责获取时间，文件命名为remoteStart.java

package com.test;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.RemoteException;
import android.util.Log;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;
import android.widget.Toast;
public class remoteStart extends Activity {
private String TAG="remoteStart";
private RadioGroup radiogroup;
private RadioButton donothing;
private RadioButton start;
private RadioButton pause;
private RadioButton stop;
private TextView text;
private boolean status=true;
private IremoteService remoteservice;
private String time;
private getTimeThread gettimethread;
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.remote);
radiogroup=(RadioGroup)findViewById(R.id.radioGroup1);
donothing=(RadioButton)findViewById(R.id.radio0);
start=(RadioButton)findViewById(R.id.radio1);
pause=(RadioButton)findViewById(R.id.radio2);
stop=(RadioButton)findViewById(R.id.radio3);
text=(TextView)findViewById(R.id.radioText);
//初始化更新时间的线程
gettimethread=new getTimeThread();
radiogroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
if(start.getId()==checkedId){
if(!status){
//如果点击过暂停服务，则重新启动更新时间线程
gettimethread=new getTimeThread();
status=true;
}
new Thread(gettimethread).start();
Toast.makeText(getApplicationContext(),"启动服务" , Toast.LENGTH_SHORT).show();
}
else if(pause.getId()==checkedId){
status=false;
Toast.makeText(getApplicationContext(),"暂停服务" , Toast.LENGTH_SHORT).show();
}
else if(stop.getId()==checkedId){
stopactivity();
Toast.makeText(getApplicationContext(),"停止服务" , Toast.LENGTH_SHORT).show();
}
else{
Toast.makeText(getApplicationContext(),"啥也不做" , Toast.LENGTH_SHORT).show();
}
}
});
Log.d(TAG,"connecting");
Intent intent=new Intent("com.test.remoteService");
bindService(intent,sc,Context.BIND_AUTO_CREATE);
}
/*
* 该线程负责从服务端获取时间，并更新显示
*/
class getTimeThread implements Runnable{
public void run(){
while(status){
try {
time=remoteservice.getTime();
Log.d(TAG,time);
} catch (RemoteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Message msg=new Message();
msg.what=1;
h.sendMessage(msg);
try {
//每秒更新一次
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
};
/*
* 负责接受信息，并根据信息更新显示的时间
*/
Handler h=new Handler(){
public void handleMessage(Message msg){
Log.d(TAG,"msg is "+msg.toString());
switch(msg.what){
case 1:
//更新显示
text.setText(time);
break;
}
}
};
/*
* 停止服务，并终止
*/
public void stopactivity(){
try {
status=false;
this.unbindService(sc);
remoteservice.stop();
this.finish();
} catch (RemoteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
ServiceConnection sc=new ServiceConnection(){
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
remoteservice=IremoteService.Stub.asInterface(service);
}
@Override
public void onServiceDisconnected(ComponentName name) {
remoteservice=null;
}
};
}

在服务端，相对来说比较简单只是获取系统的时间而已，类命名为remoteService.java

package com.test;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.os.RemoteException;
import android.util.Log;
import java.text.SimpleDateFormat;
import java.util.Date;
public class remoteService extends Service {
private String TAG="remoteService";
private String time;
//设置时间格式
private SimpleDateFormat format=new SimpleDateFormat( "yyyy MMM d EEE HH:mm:ss");
private IremoteService.Stub binder=new IremoteService.Stub() {
@Override
public String getTime() throws RemoteException {
Log.d(TAG,"gettime");
//获取系统时间
time=format.format((new Date()));
return time;
}
@Override
public void stop() throws RemoteException {
Log.d(TAG,"stop");
stopSelf();
}
};
@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return binder;
}
public void onCreate(){
super.onCreate();
Log.d(TAG,"oncreate");
}
}

现在就可以了，界面如下图所示，显示的时间会每秒更新一次。

此外，系统想要顺利运行似乎还缺了几个文件，分别为value目录下的strings.xml和color.xml，下面是strings.xml。

<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="hello">请选择</string>
<string name="app_name">Service练习</string>
<string name="dirct_start">直接启动service</string>
<string name="bind_start">bind启动service</string>
<string name="remote_start">远程启动service</string>
<string name="do_nothing">啥也不做</string>
<string name="start">启动服务</string>
<string name="pause">暂停服务</string>
<string name="stop">停止服务</string>
<string-array name="actions">
<item>啥也不做</item>
<item>启动服务</item>
<item>暂停服务</item>
<item>停止服务</item>
</string-array>
<string name="select">选择一个操作</string>
</resources>

下面为color.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="bachgroud">#7fffffff</color>
<color name="textback">#77777777</color>
</resources>

至此，我这个系统终于大功告成了。

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