Question

在我的一项活动中，我有一个ListView和两个Buttons名为＆＃34;启动服务＆＃34;和＃34;停止服务＆＃34; 在＆＃34;开始服务＆＃34;。 StartServiceActivity.class调用extends Service，并使用onStartCommand()方法sendBroadcast调用ServiceSecondActivity并传递一些数据。

我的第三课extends BroadcastReceiver Toasts 接收消息并使用BroadcastReceiver

显示消息

现在我要做的是从中获取收到的数据 ListView并在BroadcastReceiver上显示。我已经完成了代码但是我不知道我在哪里放置Button对象的代码它运行，
我无法通过＆＃34;停止服务＆＃34;停止我的服务public class ServiceActivity extends Activity implements OnClickListener { ListView lstv; Button bstart, bstop; private BroadcastReceiver broadcastReceiver; String data[]; private IntentFilter filter; Messenger mService; Boolean mBound; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.service_layout); bstart = (Button) findViewById(R.id.bStart); bstop = (Button) findViewById(R.id.bStop); bstart.setOnClickListener(this); bstop.setOnClickListener(this); lstv=(ListView)findViewById(R.id.lst); broadcastReceiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { data = new String[] { intent.getStringExtra("name"), intent.getStringExtra("message"), intent.getStringExtra("TimeStamp") }; ArrayAdapter<String> adp=new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1, data); lstv.setAdapter(adp); } }; registerReceiver(broadcastReceiver, filter); Toast.makeText(getApplicationContext(), "data : "+ data, Toast.LENGTH_LONG).show(); } @Override protected void onResume() { // TODO Auto-generated method stub super.onResume(); } @Override protected void onPause() { // TODO Auto-generated method stub super.onPause(); unregisterReceiver(broadcastReceiver); } @Override public void onClick(View arg0) { //registerReceiver(broadcastReceiver, filter); switch (arg0.getId()) { case R.id.bStart: Intent i = new Intent(getApplicationContext(), StartServiceActivity.class); startService(i); break; case R.id.bStop: Intent ii = new Intent(getApplicationContext(), StartServiceActivity.class); //unregisterReceiver(broadcastReceiver); stopService(ii); break; default: break; } } }。

1）第一项活动

public class StartServiceActivity extends Service{

ListView lvl;
private PendingIntent pendingIntent;
int count=1;
Long stm;
@Override
public void onCreate() {
    // TODO Auto-generated method stub
    super.onCreate();
    Toast.makeText(getApplicationContext(), "Service Created", Toast.LENGTH_SHORT).show();

}

@Override
public Context getApplicationContext() {
    // TODO Auto-generated method stub
    return super.getApplicationContext();
}

@Override
public void onStart(Intent intent, int startId) {
    // TODO Auto-generated method stub
    super.onStart(intent, startId);
    Toast.makeText(getApplicationContext(), "Service Started", Toast.LENGTH_SHORT).show();  

    Notification notification=new Notification(R.drawable.ic_launcher, "Service " + count++, System.currentTimeMillis());

    Intent inte=new Intent(getApplicationContext(), ServiceActivity.class);

    PendingIntent penIn=PendingIntent.getActivity(getApplicationContext(), 0, inte, 0);

    notification.setLatestEventInfo(getApplicationContext(), "Service ", "Service is running", penIn);

    startForeground(20, notification);      
}   
    public int onStartCommand(Intent intent, int flags, int startId) {

           stm=System.currentTimeMillis()+ 5*1000; 
            while (System.currentTimeMillis()< stm) {

                Intent ii=new Intent(getApplicationContext(), ServiceSecondActivity.class);
                ii.putExtra("name", "abc");
                ii.putExtra("message", "Number"+ count++);
                ii.putExtra("TimeStamp", "TimeStamp :"+stm);
                ii.setAction("demo.example.app_5_1_15.CUSTOM_INTENT");
                sendBroadcast(ii);
            }   

@Override
public void onDestroy() {
    // TODO Auto-generated method stu
    stopForeground(true);
    stopSelf();

    super.onDestroy();
    Toast.makeText(getApplicationContext(), "Service Stopped", Toast.LENGTH_SHORT).show();
}
}

2）班级wchich扩展服务

public class ServiceSecondActivity extends BroadcastReceiver{

@Override
public void onReceive(Context context, Intent intent) {

    CharSequence csName=intent.getCharSequenceExtra("name");
    CharSequence csMsg=intent.getCharSequenceExtra("message");
    CharSequence csTime=intent.getCharSequenceExtra("TimeStamp");

    Toast.makeText(context, "msg : "+csName + " : " + csMsg +" : " + csTime, Toast.LENGTH_SHORT).show();
}
}

3）扩展BroadcastReceiver的类

FATAL EXCEPTION: main
java.lang.NullPointerException
at android.app.ContextImpl.stopServiceAsUser(ContextImpl.java:1389)
at android.app.ContextImpl.stopService(ContextImpl.java:1359)
at android.content.ContextWrapper.stopService(ContextWrapper.java:455)
at demo.example.app_5_1_15.ServiceActivity.onClick(ServiceActivity.java:120)
at android.view.View.performClick(View.java:4202)
at android.view.View$PerformClick.run(View.java:17340)
at android.os.Handler.handleCallback(Handler.java:725)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5039)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
at dalvik.system.NativeStart.main(Native Method)

错误日志

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Answer 1

（我不懂英文。） 1.我不知道，但如果您想发送数据，可以使用Message in android。 2.服务是singelton所以我可以通过再次启动来阻止它，但不同的意图是单独停止它。

按钮：

Intent ii = new Intent(getApplicationContext(),
            StartServiceActivity.class);
            ii.putExtras("stop",1);
startService(ii);

在您的服务中：

public int onStartCommand(Intent intent, int flags, int startId) {
if (intent.hasExtra("stop") ) {
    //stop it now
    stopForeground(true);
    stopSelf();
}else{
//.............
}

}

无法在Android中停止服务，无法在ListView中显示已接收的消息

1 个答案: