Click back button twice to exit the application
- agulevski10
- Nov 14, 2019
- 2 min read
This is simple example how to implement double-click on back button to exit the application. There will be a message alerting you that clicking again on back button will exit.
This is a standard Java code for executing this feature:
Java
private boolean doubleBackToExitPressedOnce = false; @Override public void onBackPressed() { if (doubleBackToExitPressedOnce) { super.onBackPressed(); return; } this.doubleBackToExitPressedOnce = true; Toast.makeText(this, "Press back again to exit", Toast.LENGTH_SHORT).show(); new Handler().postDelayed(new Runnable() { @Override public void run() { doubleBackToExitPressedOnce = false; } }, 2000); }
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private boolean doubleBackToExitPressedOnce = false;
@Override
public void onBackPressed() {
if (doubleBackToExitPressedOnce) {
super.onBackPressed();
return;
}
this.doubleBackToExitPressedOnce = true;
Toast.makeText(this, "Press back again to exit", Toast.LENGTH_SHORT).show();
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
doubleBackToExitPressedOnce = false;
}
}, 2000);
}
And here we use Java Lambda:
Java
@Override public void onBackPressed() { if (doubleBackToExitPressedOnce) { super.onBackPressed(); return; } this.doubleBackToExitPressedOnce = true; Toast.makeText(this, "Press back again to exit", Toast.LENGTH_SHORT).show(); new Handler().postDelayed(() -> doubleBackToExitPressedOnce = false, 2000); }
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@Override
public void onBackPressed() {
if (doubleBackToExitPressedOnce) {
super.onBackPressed();
return;
}
this.doubleBackToExitPressedOnce = true;
Toast.makeText(this, "Press back again to exit", Toast.LENGTH_SHORT).show();
new Handler().postDelayed(() -> doubleBackToExitPressedOnce = false, 2000);
}
And here is an example using Kotlin in Android:
class HomeActivity : AppCompatActivity() { private var doubleBackToExitPressedOnce: Boolean = false override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main2) } override fun onBackPressed() { if (doubleBackToExitPressedOnce) { super.onBackPressed() return } this.doubleBackToExitPressedOnce = true Toast.makeText(this, "Press back again to exit", Toast.LENGTH_SHORT).show() Handler().postDelayed({ doubleBackToExitPressedOnce = false }, 2000) } }
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class HomeActivity : AppCompatActivity() {
private var doubleBackToExitPressedOnce: Boolean = false
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main2)
}
override fun onBackPressed() {
if (doubleBackToExitPressedOnce) {
super.onBackPressed()
return
}
this.doubleBackToExitPressedOnce = true
Toast.makeText(this, "Press back again to exit", Toast.LENGTH_SHORT).show()
Handler().postDelayed({ doubleBackToExitPressedOnce = false }, 2000)
}
}
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