एंड्रॉइड में एक तंत्र है जो अपने प्रलेखन के अनुसार किसी एप्लिकेशन को सुरक्षित रूप से बंद करने के लिए है। अंतिम गतिविधि में जो बाहर है (आमतौर पर मुख्य गतिविधि जो पहली बार शुरू हुई थी जब आवेदन शुरू हुआ था) बस ऑनडेस्ट्रो () विधि में कुछ पंक्तियों को रखें। System.runFinalizersOnExit (true) पर कॉल यह सुनिश्चित करता है कि आवेदन के बाहर आने पर सभी वस्तुओं को अंतिम रूप दिया जाएगा और कचरा एकत्र किया जाएगा। यदि आप चाहें तो आप android.os.Process.killProcess (android.os.Process.myPid ()) के माध्यम से किसी एप्लिकेशन को जल्दी से मार सकते हैं। ऐसा करने का सबसे अच्छा तरीका एक सहायक कक्षा में निम्नलिखित की तरह एक विधि है और फिर जब भी ऐप को मारना होगा, तब इसे कॉल करें। उदाहरण के लिए रूट गतिविधि की विध्वंस विधि (यह मानते हुए कि ऐप इस गतिविधि को कभी नहीं मारता):
इसके अलावा एंड्रॉयड के एक आवेदन को सूचित नहीं करेगी गृह महत्वपूर्ण घटना है, तो आप पास आवेदन नहीं कर सकते जब घर कुंजी दबाया जाता है। Android स्वयं के लिए होम कुंजी ईवेंट को सुरक्षित रखता है ताकि एक डेवलपर अपने एप्लिकेशन को छोड़ने से उपयोगकर्ताओं को रोक न सके। हालाँकि आप गृह कुंजी के साथ निर्धारित कर सकते हैं कि एक सहायक वर्ग में एक ध्वज को सही करने के लिए एक ध्वज सेट करके दबाया जाता है जो मानता है कि गृह कुंजी दबाया गया है, फिर ध्वज को झूठी में तब परिवर्तित करना जब कोई घटना घटित होती है, जिससे पता चलता है कि गृह कुंजी दबाया नहीं गया था और फिर गतिविधि के onStop () विधि में दबाए गए गृह कुंजी को देखने के लिए जाँच ।
किसी भी मेनू के लिए और मेनू द्वारा शुरू की गई गतिविधियों में गृह कुंजी को संभालने के लिए मत भूलना । वही SEARCH कुंजी के लिए जाता है । नीचे उदाहरण के लिए कुछ उदाहरण दिए गए हैं:
यहां एक रूट एक्टिविटी का एक उदाहरण दिया गया है जो नष्ट होने पर एप्लिकेशन को मारता है:
package android.example;
/**
* @author Danny Remington - MacroSolve
*/
public class HomeKey extends CustomActivity {
public void onDestroy() {
super.onDestroy();
/*
* Kill application when the root activity is killed.
*/
UIHelper.killApp(true);
}
}
यहां एक अमूर्त गतिविधि है जिसे गृह कुंजी को संभालने के लिए बढ़ाया जा सकता है, जो इसे विस्तारित करती है:
package android.example;
/**
* @author Danny Remington - MacroSolve
*/
import android.app.Activity;
import android.view.Menu;
import android.view.MenuInflater;
/**
* Activity that includes custom behavior shared across the application. For
* example, bringing up a menu with the settings icon when the menu button is
* pressed by the user and then starting the settings activity when the user
* clicks on the settings icon.
*/
public abstract class CustomActivity extends Activity {
public void onStart() {
super.onStart();
/*
* Check if the app was just launched. If the app was just launched then
* assume that the HOME key will be pressed next unless a navigation
* event by the user or the app occurs. Otherwise the user or the app
* navigated to this activity so the HOME key was not pressed.
*/
UIHelper.checkJustLaunced();
}
public void finish() {
/*
* This can only invoked by the user or the app finishing the activity
* by navigating from the activity so the HOME key was not pressed.
*/
UIHelper.homeKeyPressed = false;
super.finish();
}
public void onStop() {
super.onStop();
/*
* Check if the HOME key was pressed. If the HOME key was pressed then
* the app will be killed. Otherwise the user or the app is navigating
* away from this activity so assume that the HOME key will be pressed
* next unless a navigation event by the user or the app occurs.
*/
UIHelper.checkHomeKeyPressed(true);
}
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.settings_menu, menu);
/*
* Assume that the HOME key will be pressed next unless a navigation
* event by the user or the app occurs.
*/
UIHelper.homeKeyPressed = true;
return true;
}
public boolean onSearchRequested() {
/*
* Disable the SEARCH key.
*/
return false;
}
}
यहां एक मेनू स्क्रीन का उदाहरण दिया गया है जो गृह कुंजी को संभालती है :
/**
* @author Danny Remington - MacroSolve
*/
package android.example;
import android.os.Bundle;
import android.preference.PreferenceActivity;
/**
* PreferenceActivity for the settings screen.
*
* @see PreferenceActivity
*
*/
public class SettingsScreen extends PreferenceActivity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.layout.settings_screen);
}
public void onStart() {
super.onStart();
/*
* This can only invoked by the user or the app starting the activity by
* navigating to the activity so the HOME key was not pressed.
*/
UIHelper.homeKeyPressed = false;
}
public void finish() {
/*
* This can only invoked by the user or the app finishing the activity
* by navigating from the activity so the HOME key was not pressed.
*/
UIHelper.homeKeyPressed = false;
super.finish();
}
public void onStop() {
super.onStop();
/*
* Check if the HOME key was pressed. If the HOME key was pressed then
* the app will be killed either safely or quickly. Otherwise the user
* or the app is navigating away from the activity so assume that the
* HOME key will be pressed next unless a navigation event by the user
* or the app occurs.
*/
UIHelper.checkHomeKeyPressed(true);
}
public boolean onSearchRequested() {
/*
* Disable the SEARCH key.
*/
return false;
}
}
यहाँ एक सहायक वर्ग का उदाहरण दिया गया है जो ऐप में गृह कुंजी को संभालता है :
package android.example;
/**
* @author Danny Remington - MacroSolve
*
*/
/**
* Helper class to help handling of UI.
*/
public class UIHelper {
public static boolean homeKeyPressed;
private static boolean justLaunched = true;
/**
* Check if the app was just launched. If the app was just launched then
* assume that the HOME key will be pressed next unless a navigation event
* by the user or the app occurs. Otherwise the user or the app navigated to
* the activity so the HOME key was not pressed.
*/
public static void checkJustLaunced() {
if (justLaunched) {
homeKeyPressed = true;
justLaunched = false;
} else {
homeKeyPressed = false;
}
}
/**
* Check if the HOME key was pressed. If the HOME key was pressed then the
* app will be killed either safely or quickly. Otherwise the user or the
* app is navigating away from the activity so assume that the HOME key will
* be pressed next unless a navigation event by the user or the app occurs.
*
* @param killSafely
* Primitive boolean which indicates whether the app should be
* killed safely or quickly when the HOME key is pressed.
*
* @see {@link UIHelper.killApp}
*/
public static void checkHomeKeyPressed(boolean killSafely) {
if (homeKeyPressed) {
killApp(true);
} else {
homeKeyPressed = true;
}
}
/**
* Kill the app either safely or quickly. The app is killed safely by
* killing the virtual machine that the app runs in after finalizing all
* {@link Object}s created by the app. The app is killed quickly by abruptly
* killing the process that the virtual machine that runs the app runs in
* without finalizing all {@link Object}s created by the app. Whether the
* app is killed safely or quickly the app will be completely created as a
* new app in a new virtual machine running in a new process if the user
* starts the app again.
*
* <P>
* <B>NOTE:</B> The app will not be killed until all of its threads have
* closed if it is killed safely.
* </P>
*
* <P>
* <B>NOTE:</B> All threads running under the process will be abruptly
* killed when the app is killed quickly. This can lead to various issues
* related to threading. For example, if one of those threads was making
* multiple related changes to the database, then it may have committed some
* of those changes but not all of those changes when it was abruptly
* killed.
* </P>
*
* @param killSafely
* Primitive boolean which indicates whether the app should be
* killed safely or quickly. If true then the app will be killed
* safely. Otherwise it will be killed quickly.
*/
public static void killApp(boolean killSafely) {
if (killSafely) {
/*
* Notify the system to finalize and collect all objects of the app
* on exit so that the virtual machine running the app can be killed
* by the system without causing issues. NOTE: If this is set to
* true then the virtual machine will not be killed until all of its
* threads have closed.
*/
System.runFinalizersOnExit(true);
/*
* Force the system to close the app down completely instead of
* retaining it in the background. The virtual machine that runs the
* app will be killed. The app will be completely created as a new
* app in a new virtual machine running in a new process if the user
* starts the app again.
*/
System.exit(0);
} else {
/*
* Alternatively the process that runs the virtual machine could be
* abruptly killed. This is the quickest way to remove the app from
* the device but it could cause problems since resources will not
* be finalized first. For example, all threads running under the
* process will be abruptly killed when the process is abruptly
* killed. If one of those threads was making multiple related
* changes to the database, then it may have committed some of those
* changes but not all of those changes when it was abruptly killed.
*/
android.os.Process.killProcess(android.os.Process.myPid());
}
}
}