问题
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?
回答1:
Android's design does not favor exiting an application by choice, but rather manages it by the OS. You can bring up the Home application by its corresponding Intent:
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
回答2:
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();
}
回答3:
System.exit(0);
Is probably what you are looking for. It will close the entire application and take you to the home Screen.
回答4:
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
}
回答5:
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();
回答6:
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.
回答7:
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();
}
回答8:
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.
回答9:
(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
}
回答10:
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
回答11:
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();
回答12:
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.
回答13:
Add following lines after finish(); in onDestroy():
android.os.Process.killProcess(android.os.Process.myPid());
super.onDestroy();
回答14:
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;
}
}
}
回答15:
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'
}
}
回答16:
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);
}
回答17:
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();
}
});
回答18:
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);
}
来源：https://stackoverflow.com/questions/3226495/how-to-exit-from-the-application-and-show-the-home-screen