[android] How to exit from the application and show the home screen?

I have an application where on the home page I have buttons for navigation through the application.

On that page I have a button "EXIT" which when clicked should take the user to the home screen on the phone where the application icon is.

How can I do that?

It is not recommended to exit your Android Application. See this question for more details.

The user can always quit your app through the home button or in the first activity through the back button.

If you want to exit from your application. Then use this code inside your button pressed event. like:

public void onBackPressed()
{
    moveTaskToBack(true);
    android.os.Process.killProcess(android.os.Process.myPid());
    System.exit(1);
}

(I tried previous answers but they lacks in some points. For example if you don't do a return; after finishing activity, remaining activity code runs. Also you need to edit onCreate with return. If you doesn't run super.onCreate() you will get a runtime error)

Say you have MainActivity and ChildActivity.

Inside ChildActivity add this:

Intent intent = new Intent(ChildActivity.this, MainActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
intent.putExtra("EXIT", true);
startActivity(intent);
return true;

Inside MainActivity's onCreate add this:

@Override
public void onCreate(Bundle savedInstanceState) {

    mContext = getApplicationContext();

    super.onCreate(savedInstanceState);

    if (getIntent().getBooleanExtra("EXIT", false)) {
        finish();
        return;
    }
    // your current codes
    // your current codes
}

May be you can try something like this

Suppose in our application, we have a number of activities(say ten) and we need to exit directly from this activity. What we can do is, create an intent and go to the root activity and set flag in the intent as

intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

also, add some extra like boolean to the intent

intent.putExtra("EXIT", true);

Then in root activity, check the value of the boolean and according to that call finish(), in the onCreate() of the root activity

if (getIntent().getBooleanExtra("EXIT", false)) {
 finish();
}

if you want to exit application put this code under your function

public void yourFunction()
{
finishAffinity();   
moveTaskToBack(true);

}



//For an instance, if you want to exit an application on double click of a 
//button,then the following code can be used.
@Override
public boolean onKeyDown(int keyCode, KeyEvent event)  {
    if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 2) {
        // do something on back.
        From Android 16+ you can use the following:

        finishAffinity();
        moveTaskToBack(true);
    }

    return super.onKeyDown(keyCode, event);
}

Add following lines after finish(); in onDestroy():

android.os.Process.killProcess(android.os.Process.myPid());
super.onDestroy();

Maybe my code can hepls (Main_Activity.java):

    @Override
    protected void onDestroy() {
        super.onDestroy();
        this.finish();
        exit(0);
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event)  {
        switch(keyCode)    {
            case KeyEvent.KEYCODE_BACK:
                AlertDialog.Builder builder = new AlertDialog.Builder(this);
                builder.setTitle("My application").setMessage("Keep playing?").setIcon(R.drawable.icon);
                // Go to backgroung
                builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) { moveTaskToBack(true); }
                });
                // Exit from app calling protected void onDestroy()
                builder.setNegativeButton("CLOSE APPLICATION", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) { onDestroy(); }
                });
                // Close this dialog
                builder.setNeutralButton("CANCEL", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) { dialog.cancel(); }
                });
                AlertDialog dialog = builder.create();
                dialog.show();
                return true;
        }
        return false;
    }

first finish your application using method finish();

and then add below lines in onDestroy for Removing Force close

android.os.Process.killProcess(android.os.Process.myPid());
super.onDestroy();

System.exit(0);

Is probably what you are looking for. It will close the entire application and take you to the home Screen.

When u call finish onDestroy() of that activity will be called and it will go back to previous activity in the activity stack... So.. for exit do not call finish();

Some Activities actually you don't want to open again when back button pressed such Splash Screen Activity, Welcome Screen Activity, Confirmation Windows. Actually you don't need this in activity stack. you can do this using=> open manifest.xml file and add a attribute

android:noHistory="true"

to these activities.

<activity
    android:name="com.example.shoppingapp.AddNewItems"
    android:label="" 
    android:noHistory="true">
</activity>

OR

Sometimes you want close the entire application in certain back button press. Here best practice is open up the home window instead of exiting application. For that you need to override onBackPressed() method. usually this method open up the top activity in the stack.

@Override
public void onBackPressed(){
Intent a = new Intent(Intent.ACTION_MAIN);
a.addCategory(Intent.CATEGORY_HOME);
a.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(a);

}

OR

In back button pressed you want to exit that activity and also you also don't want to add this in activity stack. call finish() method inside onBackPressed() method. it will not make close the entire application. it will go for the previous activity in the stack.

@Override
public void onBackPressed() {
  finish();
}

I tried exiting application using following code snippet, this it worked for me. Hope this helps you. i did small demo with 2 activities

first activity

public class MainActivity extends Activity implements OnClickListener{
    private Button secondActivityBtn;
    private SharedPreferences pref;
    private SharedPreferences.Editor editer;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        secondActivityBtn=(Button) findViewById(R.id.SecondActivityBtn);
        secondActivityBtn.setOnClickListener(this);

        pref = this.getSharedPreferences("MyPrefsFile", MODE_PRIVATE);
        editer = pref.edit();

        if(pref.getInt("exitApp", 0) == 1){
            editer.putInt("exitApp", 0);
            editer.commit();
            finish();
        }
    }
    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.SecondActivityBtn:
            Intent intent= new Intent(MainActivity.this, YourAnyActivity.class);
            startActivity(intent);
            break;
        default:
            break;
        }
    }
}

your any other activity

public class YourAnyActivity extends Activity implements OnClickListener {
    private Button exitAppBtn;
    private SharedPreferences pref;
    private SharedPreferences.Editor editer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_any);

        exitAppBtn = (Button) findViewById(R.id.exitAppBtn);
        exitAppBtn.setOnClickListener(this);

        pref = this.getSharedPreferences("MyPrefsFile", MODE_PRIVATE);
        editer = pref.edit();
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.exitAppBtn:
            Intent main_intent = new Intent(YourAnyActivity.this,
                    MainActivity.class);
            main_intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
            startActivity(main_intent);
            editer.putInt("exitApp",1);
            editer.commit();
            break;
        default:
            break;
        }
    }
}

Here's what i did:

SomeActivity.java

 @Override
    public void onBackPressed() {
            Intent newIntent = new Intent(this,QuitAppActivity.class);
            newIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP|Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);
            startActivity(newIntent);
            finish();
    }

QuitAppActivity.java

@Override
protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      finish();
}

Basically what you did is cleared all activities from the stack and launch QuitAppActivity, that will finish the task.

There is another option, to use the FinishAffinity method to close all the tasks in the stack related to the app.

See: https://stackoverflow.com/a/27765687/1984636

I did it with observer mode.

Observer interface

public interface Observer {
public void update(Subject subject);
}

Base Subject

public class Subject {
private List<Observer> observers = new ArrayList<Observer>();

public void attach(Observer observer){
    observers.add(observer);
}

public void detach(Observer observer){
    observers.remove(observer);
}

protected void notifyObservers(){
    for(Observer observer : observers){
        observer.update(this);
    }
}
}

Child Subject implements the exit method

public class ApplicationSubject extends Subject {
public void exit(){
    notifyObservers();
}
}

MyApplication which your application should extends it

public class MyApplication extends Application {

private static ApplicationSubject applicationSubject;

public ApplicationSubject getApplicationSubject() {
            if(applicationSubject == null) applicationSubject = new ApplicationSubject();
    return applicationSubject;
}

}

Base Activity

public abstract class BaseActivity extends Activity implements Observer {

public MyApplication app;

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    app = (MyApplication) this.getApplication();
    app.getApplicationSubject().attach(this);
}

@Override
public void finish() {
    // TODO Auto-generated method stub
            app.getApplicationSubject().detach(this);
    super.finish();
}

/**
 * exit the app
 */
public void close() {
    app.getApplicationSubject().exit();
};

@Override
public void update(Subject subject) {
    // TODO Auto-generated method stub
    this.finish();
}

}

let's test it

public class ATestActivity extends BaseActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    close(); //invoke 'close'
}
}

This works well for me.
Close all the previous activities as follows:

    Intent intent = new Intent(this, MainActivity.class);
    intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
    intent.putExtra("Exit me", true);
    startActivity(intent);
    finish();

Then in MainActivity onCreate() method add this to finish the MainActivity

    setContentView(R.layout.main_layout);

    if( getIntent().getBooleanExtra("Exit me", false)){
        finish();
        return; // add this to prevent from doing unnecessary stuffs
    }

100% works fine. this is code for Exit your app onClick (Method)

    Button exit = (Button)findViewById(R.id.exitbutton);

    exit.setOnClickListener(new View.OnClickListener() {

        @Override

        public void onClick(View view) {

            finish();
            android.os.Process.killProcess(android.os.Process.myPid());
            System.exit(1);
            Toast.makeText(getApplicationContext(), "Closed Completely and Safely", Toast.LENGTH_LONG).show();

        }
    });

If you want to end an activity you can simply call finish(). It is however bad practice to have an exit button on the screen.

You can just add moveTaskToBack(true) in your exit button's onClickedListener to minimize the application.

Hope it helps.