Develop Reference

How to kill background Activity in Android studio

I have the MainActivity and the secon_Activity in Android Studio, from MainActivity I go to second_Activity using Intent, then in the second_Activity I want to finish that activity, I do it but the first activity remains in background, how can I do to end or kill both activities.
Here the MainActivity:
public class MainActivity extends AppCompatActivity {
Button send_button;
EditText send_text;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_first_activity);
send_button = (Button)findViewById(R.id.send_button_id);
send_text = (EditText)findViewById(R.id.send_text_id);
send_button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v){
String str = send_text.getText().toString();
Intent intent = new Intent(getApplicationContext(), Second_activity.class);
intent.putExtra("message_key", str);
startActivity(intent);
finish();
}
});
}
}
Here de second_Activity:
public class Second_activity extends AppCompatActivity {
TextView receiver_msg;
Button finish_button;
#Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second_activity);
receiver_msg = (TextView)findViewById(R.id.received_value_id);
finish_button = (Button)findViewById(R.id.finish_button_id);
Intent intent = getIntent();
String str = intent.getStringExtra("message_key");
receiver_msg.setText(str);
finish_button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v){
finish();
}
});
}
}

I've built a Kiosk app and from my searching you can't remove it from the "recent" apps.
You can how ever, use ActivityManager as follows:
ActivityManager am = (ActivityManager) Context.getSystemService(ACTIVITY_SERVICE);
am.moveTaskToFront(myAppId, 0);
am.killBackgroundProcesses(Activity_A_Package_Name);
Requires:
<uses-permission android:name="android.permission.KILL_BACKGROUND_PROCESSES" />
It should kill it, usually.

you can use System.exit(1) instead of finish()

How to close an activity from another activity Android

I am developing android app in which I have 2 activities. I want to close activity A from activity B on button press and recreate activity A. How to do it need help?

You can use sendBroadcast method, by this way you can close one or more activities.
In your ActivityB use this code:
public class ActivityA extends AppCompatActivity {
public static final String FINISH_ALERT = "finish_alert";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.registerReceiver(this.finishAlert, new IntentFilter(FINISH_ALERT));
}
BroadcastReceiver finishAlert = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
ActivityA.this.finish();
}
};
#Override
public void onDestroy() {
super.onDestroy();
this.unregisterReceiver(finishAlert);
}
}
and in your ActivityB call this command to finish it:
Intent i = new Intent(ActivityA.FINISH_ALERT);
this.sendBroadcast(i);

Close app in onBackPressed()'s MainActivity

I want my app to close when I press the back button on MainActivity. Currently when I press it on MainActivity, it returns to previous activity.

#Override
public void onBackPressed() {
YourActivity.this.finish();
}
It's worth noting that changing the default behavior is not a good idea.

You can use System.exit(0).
#Override
public void onBackPressed() {
System.exit(0);
}

Why would you want your app to not go back to previous activities?
If your MainActivity is started by an activity you don't want to go back to, its better to add flags to the intent that started MainActivity so the previous activity would not stay in the Task-stack.
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
If you dont want to do that, you must override the OnBackPress() to remove/finish the Tasks under the MainActivity in the stack.
This can be done with a LocalBroadcaster for example, even though its quite ugly.
In the activity you want to close:
BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
finish();
}
};
#Override
protected void onResume() {
super.onResume();
IntentFilter filter = new IntentFilter("Your filter");
LocalBroadcastManager.getInstance(this).registerReceiver(broadcastReceiver, filter);
}
#Override
protected void onDestroy() {
super.onDestroy();
LocalBroadcastManager.getInstance(this).unregisterReceiver(broadcastReceiver);
}
In your MainActivity:
#Override
public void onBackPressed() {
Intent intentBroadcast = new Intent("Your filter");
LocalBroadcastManager.getInstance(MainActivity.this).sendBroadcast(intentBroadcast);
finish();
}

Exiting an Android Application On back button

I have an application in which I have different activities. In 1 activity, I want that when the user presses the back button, I want the application to be closed and home screen is displayed
Code
public boolean onKeyDown(int keyCode, KeyEvent event)
{
//Handle the back button
if(keyCode == KeyEvent.KEYCODE_BACK)
{
//Ask the user if they want to quit
new AlertDialog.Builder(this)
.setIcon(android.R.drawable.ic_dialog_alert)
.setTitle("Exit")
.setMessage("Really Exit ?")
.setPositiveButton("Yes", new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dialog, int which)
{
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
}
})
.setNegativeButton("No", null)
.show();
return true;
}
else
{
return super.onKeyDown(keyCode, event);
}
}
When I run this and press the back button, the home screen is displayed, but when I run it for the second time, I get a console output as
ActivityManager: Warning: Activity not started, its current task has been brought to the front.
And the activity in which the back button is pressed gets displayed.
I think the application does not get killed and runs in background. Just to mention, this is not the starting activity of my application.
Can somebody help me, I am beginner.

Try this code :
#Override
public void onBackPressed()
{
moveTaskToBack(true);
}
Also check this Link

For each and every Intent you have used for going into other activity u have to follow this way for passing intent just pass flag to each intent as given below and after starting Activity using startActivity() u have to add finish() after that demo code as given below
Intent i=new Intent(firstActivity.this,secondActivity.class);
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
finish();

You cannot kill your application at your will. The android OS will do it when it wishes to free the resources allocated to it. You cannot actually implement the exit application concept in android. The user can simply navigate away from your Activity and return to it. If it has to be restarted from the first Activity or resumed where it left, is upto the android OS, not you.
Read this post to understand the philosophy of how android apps should be designed and why you wouldn't want to exit at your will:
Is quitting an application frowned upon?

Add finish(); after that line startActivity(intent) it finish your activity.
Thanks

you need to include this class as such in your code.........
public abstract class AppBaseActivity extends Activity {
public static final String FINISH_ALL_ACTIVITIES_ACTIVITY_ACTION = "com.hrupin.FINISH_ALL_ACTIVITIES_ACTIVITY_ACTION";
private BaseActivityReceiver baseActivityReceiver = new BaseActivityReceiver();
public static final IntentFilter INTENT_FILTER = createIntentFilter();
private static IntentFilter createIntentFilter(){
IntentFilter filter = new IntentFilter();
filter.addAction(FINISH_ALL_ACTIVITIES_ACTIVITY_ACTION);
return filter;
}
protected void registerBaseActivityReceiver() {
registerReceiver(baseActivityReceiver, INTENT_FILTER);
}
protected void unRegisterBaseActivityReceiver() {
unregisterReceiver(baseActivityReceiver);
}
public class BaseActivityReceiver extends BroadcastReceiver{
#Override
public void onReceive(Context context, Intent intent) {
if(intent.getAction().equals(FINISH_ALL_ACTIVITIES_ACTIVITY_ACTION)){
finish();
}
}
}
protected void closeAllActivities(){
sendBroadcast(new Intent(FINISH_ALL_ACTIVITIES_ACTIVITY_ACTION));
}
}
Then you need to extend all other classes from this class just as in an example below:
public class FirstActivity extends AppBaseActivity implements OnClickListener {
/** Called when the activity is first created. */
private Button buttonOpenNextActivity;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.first);
registerBaseActivityReceiver();
buttonOpenNextActivity = (Button)findViewById(R.id.buttonOpenNextActivity);
buttonOpenNextActivity.setOnClickListener(this);
}
#Override
protected void onDestroy() {
super.onDestroy();
unRegisterBaseActivityReceiver();
}
#Override
public void onClick(View v) {
/* OPEN SECOND ACTIVITY.*/
startActivity(new Intent(this, SecondActivity.class));
}
}
Another class:
public class SecondActivity extends AppBaseActivity implements OnClickListener {
private Button buttonOpenNextActivity;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.second);
registerBaseActivityReceiver();
buttonOpenNextActivity = (Button)findViewById(R.id.buttonOpenNextActivity);
buttonOpenNextActivity.setOnClickListener(this);
}
#Override
protected void onDestroy() {
super.onDestroy();
unRegisterBaseActivityReceiver();
}
#Override
public void onClick(View v) {
/* OPEN THIRD ACTIVITY.*/
startActivity(new Intent(this, ThirdActivity.class));
}
}
Last Class:
public class ThirdActivity extends AppBaseActivity implements OnClickListener {
private Button buttonCloseAllActivities;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.third);
registerBaseActivityReceiver();
buttonCloseAllActivities = (Button)findViewById(R.id.buttonCloseAllActivities);
buttonCloseAllActivities.setOnClickListener(this);
}
#Override
protected void onDestroy() {
super.onDestroy();
unRegisterBaseActivityReceiver();
}
#Override
protected void onBackPressed() {
closeAllActivities();
super.onBackPressed();
}
}
Now when you press back button in third activity all other activities will also be finished altogether.
1/ dont forget to register the reciever in onCreate and unregister() it in ondestroy().

Your question is not clear dear.
As per my knowledge you should use broadCast Reciever for finishing the application and passing the intent to home Screen.
MoreOver Warning is nothing , before running your application just press Enter in your code or give sm space and den save it and re- run you appication.It will work fine....

if you want to exit your application on back press then you have to finish all the previous activities when you press the back button on that screen for this you should use the concept of BROADCAST RECIEVER ...... means you have broadcast an intent on that back press which will finish all the previous activities.

Multiple page switching in android eclipse

Consider i am using five screen pages for project "A".Each page is having switching between other pages sequentially one by one,my need is to do close all the page when i am clicking the button "exit" from the page five which is the last one.
I have used this below code,but the problem is only the last page is getting close others are not.
find my code below
Button extbtn = (Button)findViewById(R.id.but_Exit);
extbtn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent intent = new Intent();
setResult(RESULT_OK, intent);
finish();
} });
Thanks for your time!

Make all five activities extend a BaseActivity that registers a BroadcastReceiver at onCreate (and unregisters at onDestroy).
When extbtn is clicked, send a broadcast to all those BaseActivities to close themselves
for example, in your BaseActivity add:
public static final String ACTION_KILL_COMMAND = "ACTION_KILL_COMMAND";
public static final String ACTION_KILL_DATATYPE = "content://ACTION_KILL_DATATYPE";
private KillReceiver mKillReceiver;
#Override
protected void onCreate(Bundle savedInstanceState) {
...
...
mKillReceiver = new KillReceiver();
registerReceiver(mKillReceiver, IntentFilter.create(ACTION_KILL_COMMAND, ACTION_KILL_DATATYPE));
}
#Override
protected void onDestroy() {
super.onDestroy();
unregisterReceiver(mKillReceiver);
}
private final class KillReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
finish();
}
}
and at extbtn's onClick call:
extbtn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// send a broadcast that will finish activities at the bottom of the stack
Intent killIntent = new Intent(BaseActivity.ACTION_KILL_COMMAND);
killIntent.setType(BaseActivity.ACTION_KILL_DATATYPE);
sendBroadcast(killIntent);
Intent intent = new Intent();
setResult(RESULT_OK, intent);
finish();
}
});