Monitoring and processing of return keys in Android apps

Mainactivity as follows:

Package com.testnbackpressed; Import Android.os.Bundle; Import android.view.KeyEvent; Import android.app.Activity;     /** * Demo Description: * Handling back Key Press event * * NOTE: * The following two ways not to use * * * public class Mainactivity extends Activity {@Override         protected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate);     Setcontentview (R.layout.main);     /** * Monitor the Back key press event, Method 1: * Note: * super.onbackpressed () will automatically call the finish () method to close * Current activity.         * To block the back keyboard, comment on the line code */@Override public void onbackpressed () {super.onbackpressed ();            System.out.println ("Press back Key onbackpressed ()");    }/** * listens to the back key press event, Method 2: * Note: * The return value indicates whether the event can be fully processed * returns false here, so the event will continue to propagate.    * The return value here is subject to availability in the specific project. */@Override public boolean onKeyDown (int keycode, keyevent event) {if (keycode = = Keyevent.keycode_back               ) {System.out.println ("Press back Key OnKeyDown ()"); RetuRN false;         }else {return Super.onkeydown (KeyCode, event);         }} @Override protected void OnDestroy () {Super.ondestroy ();     SYSTEM.OUT.PRINTLN ("Executive OnDestroy ()"); }       }

Main.xml as follows:

<relativelayout      xmlns:android= "http://schemas.android.com/apk/res/android"     xmlns:tools= "http// Schemas.android.com/tools "     android:layout_width=" match_parent "     android:layout_height=" Match_parent "     >        <textview         android:layout_width= "wrap_content"         android:layout_height= "Wrap_content"         android:text= "         android:layout_centerinparent=" true "android:textsize=" for the two processing methods of the back key "         20sp"    />    </RelativeLayout>

　　

Monitoring and processing of return keys in Android apps