我尝试创建一个服务客户端应用程序（仍在学习这些）。我的应用程序从一开始就崩溃并且不让我做任何事情。任何想法如何解决？这是我的 2 个类和清单文件。
//////////////// 1. MainActivity.java ///////////////////
public class MainActivity extends Activity {
/** Messenger for communicating with the service. */
Messenger mService = null;
/** Flag indicating whether we have called bind on the service. */
boolean mBound;
/**
* Handler of incoming messages from service.
*/
static class IncomingHandler extends Handler {
private TextView mCallbackText;
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MessengerService.MSG_SET_VALUE:
mCallbackText.setText("Received from service: " + msg.arg1);
break;
default:
super.handleMessage(msg);
}
}
}
/**
* Target we publish for clients to send messages to IncomingHandler.
*/
final Messenger mMessenger = new Messenger(new IncomingHandler());
public void sayHello(View v) {
if (!mBound) return;
// Create and send a message to the service, using a supported 'what' value
Message msg = Message.obtain(null, MessengerService.MSG_REGISTER_CLIENT, 0, 0);
try {
msg.replyTo = mMessenger;
mService.send(msg);
} catch (RemoteException e) {
e.printStackTrace();
}
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
@Override
protected void onStart() {
super.onStart();
// Bind to the service
bindService(new Intent(this, MessengerService.class), mConnection,
Context.BIND_AUTO_CREATE);
mBound = true;
}
@Override
protected void onStop() {
super.onStop();
// Unbind from the service
if (mBound) {
unbindService(mConnection);
mBound = false;
}
}
/**
* Class for interacting with the main interface of the service.
*/
private ServiceConnection mConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName className, IBinder service) {
// This is called when the connection with the service has been
// established, giving us the object we can use to
// interact with the service. We are communicating with the
// service using a Messenger, so here we get a client-side
// representation of that from the raw IBinder object.
mService = new Messenger(service);
mBound = true;
/*try {
Message msg = Message.obtain(null,
MessengerService.MSG_REGISTER_CLIENT);
msg.replyTo = mMessenger;
mService.send(msg);
// Give it some value as an example.
msg = Message.obtain(null,
MessengerService.MSG_SET_VALUE, this.hashCode(), 0);
mService.send(msg);
} catch (RemoteException e) {
e.printStackTrace();
}*/
}
public void onServiceDisconnected(ComponentName className) {
// This is called when the connection with the service has been
// unexpectedly disconnected -- that is, its process crashed.
mService = null;
mBound = false;
}
};
}
//////////////// 2. MessengerService.java ////////////////////
public class MessengerService extends Service {
String ns = Context.NOTIFICATION_SERVICE;
NotificationManager mNM = (NotificationManager) getSystemService(ns);
/** Command to the service to display a message */
static final int MSG_SAY_HELLO = 1;
/** Command to the service to register a client */
static final int MSG_REGISTER_CLIENT = 1;
/** Command to the service to unregister a client */
static final int MSG_UNREGISTER_CLIENT = 2;
/** Command to the service to set a new value */
static final int MSG_SET_VALUE = 3;
static class IncomingHandler extends Handler {
private ArrayList<Messenger> mClients = new ArrayList<Messenger>();
private int mValue=0;
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_REGISTER_CLIENT:
mClients.add(msg.replyTo);
break;
case MSG_UNREGISTER_CLIENT:
mClients.remove(msg.replyTo);
break;
case MSG_SET_VALUE:
mValue = msg.arg1;
for (int i=mClients.size()-1; i>=0; i--) {
try {
mClients.get(i).send(Message.obtain(null,
MSG_SET_VALUE, mValue, 0));
} catch (RemoteException e) {
// The client is dead. Remove it from the list;
// we are going through the list from back to front
// so this is safe to do inside the loop.
mClients.remove(i);
}
}
break;
default:
super.handleMessage(msg);
}
}
}
final Messenger mMessenger = new Messenger(new IncomingHandler());
public void onCreate() {
mNM = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
// Display a notification about us starting.
showNotification();
//handleMessage(msg);
}
@Override
public void onDestroy() {
// Cancel the persistent notification.
mNM.cancel(R.string.remote_service_started);
// Tell the user we stopped.
Toast.makeText(this, R.string.remote_service_stopped, Toast.LENGTH_SHORT).show();
}
@Override
public IBinder onBind(Intent intent) {
Toast.makeText(getApplicationContext(), "Binding..", Toast.LENGTH_SHORT).show();
return mMessenger.getBinder();
}
private void showNotification() {
// Set icon, scrolling text, etc
int icon = R.drawable.asd;
CharSequence tickerText = "Hello!";
CharSequence text = getText(R.string.remote_service_started);
long when = System.currentTimeMillis();
Context context = getApplicationContext();
//Create notication with parameters
Notification.Builder nFN = new Notification.Builder(context)
.setTicker(tickerText)
.setWhen(when)
.setSmallIcon(icon)
.setContentTitle("Test Notifications")
.setContentText(text)
.setAutoCancel(true);
// The PendingIntent to launch our activity if the user selects this notification
PendingIntent contentIntent = PendingIntent.getActivity(this, 0, new Intent(this, MessengerService.class), 0);
nFN.setContentIntent(contentIntent);
// Send the notification.
Notification n = nFN.build();
mNM.notify(R.string.remote_service_started, n);
}
}
///////////////// 3. 清单/////////////////////// /////////
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.praktiki.services.messenger"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="16"
android:targetSdkVersion="15" />
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<service
android:name=".MessengerService"
android:process=":remote"
/>
<activity
android:name=".MainActivity"
android:label="@string/title_activity_main" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>