mainactivity is as follows:
Copy Code code as follows:
Package cn.testnbackpressed;
Import Android.os.Bundle;
Import android.view.KeyEvent;
Import android.app.Activity;
/**
* Demo Description:
* Handle the Back key press event
*
* Precautions:
* The following two ways not to use together
*/
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:
Attention
* super.onbackpressed () automatically calls the finish () method to close
* Current activity.
* To block the back keyboard, note that the line code can
*/
@Override
public void onbackpressed () {
Super.onbackpressed ();
System.out.println ("Press the Back Key onbackpressed ()");
}
/**
* Monitor the Back key press event, Method 2:
Attention
* The return value indicates whether the event can be fully handled
* Returns false here, so the event continues to propagate.
* The return value here depends on the circumstances of the specific project.
*/
@Override
public boolean onKeyDown (int keycode, keyevent event) {
if ((keycode = = Keyevent.keycode_back)) {
System.out.println ("Press the Back Key OnKeyDown ()");
return false;
}else {
Return Super.onkeydown (KeyCode, event);
}
}
@Override
protected void OnDestroy () {
Super.ondestroy ();
SYSTEM.OUT.PRINTLN ("Executive OnDestroy ()");
}
}
Main.xml is as follows:
Copy Code code 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= "two ways to handle the back key"
Android:layout_centerinparent= "true"
Android:textsize= "20sp"
/>
</RelativeLayout>
