如何将数据从活动传递到正在运行的服务 [英] how to pass data from activity to running service
问题描述
我想定期将数据发送到服务器,为此我使用后台Service
,但是我想在数据更新时发送,并且我在Activity
和Activity
传递到正在运行的Service
.使用Intent
时,在启动Service
时只能发送一次数据.
I want to send data to the server periodically, I'm using background Service
for that, but I want to send when the data got updated, and updated data I'm getting in Activity
and the Service
is running in background.. so how can i pass data to running Service
from Activity
. Using Intent
I can send data only one time while starting the Service
.
Intent serviceIntent= new Intent(DriverActivity.this,demoService.class);
serviceIntent.putExtra("token", token);
startService(serviceIntent);
推荐答案
阅读本文 https://developer.android.com/guide/components/bound-services.html
例如,您可以使用Messanger
public class MessengerService extends Service {
/** Command to the service to display a message */
static final int MSG_SAY_HELLO = 1;
/**
* Handler of incoming messages from clients.
*/
class IncomingHandler extends Handler {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_SAY_HELLO:
Toast.makeText(getApplicationContext(), "hello!", Toast.LENGTH_SHORT).show();
break;
default:
super.handleMessage(msg);
}
}
}
/**
* Target we publish for clients to send messages to IncomingHandler.
*/
final Messenger mMessenger = new Messenger(new IncomingHandler());
/**
* When binding to the service, we return an interface to our messenger
* for sending messages to the service.
*/
@Override
public IBinder onBind(Intent intent) {
Toast.makeText(getApplicationContext(), "binding", Toast.LENGTH_SHORT).show();
return mMessenger.getBinder();
}
}
在Activity
或Fragment
中,您可以通过以下方式发送数据:
And in your Activity
or Fragment
you can send data in this way:
public class ActivityMessenger extends Activity {
/** Messenger for communicating with the service. */
Messenger mService = null;
/** Flag indicating whether we have called bind on the service. */
boolean mBound;
/**
* 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;
}
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;
}
};
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_SAY_HELLO, 0, 0);
try {
mService.send(msg);
} catch (RemoteException e) {
e.printStackTrace();
}
}
@Override
protected 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);
}
@Override
protected void onStop() {
super.onStop();
// Unbind from the service
if (mBound) {
unbindService(mConnection);
mBound = false;
}
}
}
如果您不知道如何使用Message
传递数据,请查看此答案 https://stackoverflow.com/a/17929775
If you don't know how to pass data with Message
look at this answer https://stackoverflow.com/a/17929775
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