Call method when home button pressed

问题

I have this method in one of my Android Activities:

@Override
public boolean onKeyDown(int keyCode, KeyEvent event)
{
    if(keyCode == KeyEvent.KEYCODE_BACK)
    {
        Log.d(\"Test\", \"Back button pressed!\");
    }
    else if(keyCode == KeyEvent.KEYCODE_HOME)
    {
        Log.d(\"Test\", \"Home button pressed!\");
    }
    return super.onKeyDown(keyCode, event);
}

But, even though the KEYCODE_HOME is valid, the log method never fires. This works for the back button though. Does anyone know why this is and how to get this to work?

回答1:

The Home button is a very dangerous button to override and, because of that, Android will not let you override its behavior the same way you do the BACK button.

Take a look at this discussion.

You will notice that the home button seems to be implemented as a intent invocation, so you'll end up having to add an intent category to your activity. Then, any time the user hits home, your app will show up as an option. You should consider what it is you are looking to accomplish with the home button. If its not to replace the default home screen of the device, I would be wary of overloading the HOME button, but it is possible (per discussion in above thread.)

回答2:

It took me almost a month to get through this. Just now I solved this issue. In your activity's onPause() you have to include the following if condition:

    if (this.isFinishing()){
        //Insert your finishing code here
    }

The function isFinishing() returns a boolean. True if your App is actually closing, False if your app is still running but for example the screen turns off.

Hope it helps!

回答3:

The HOME button cannot be intercepted by applications. This is a by-design behavior in Android. The reason is to prevent malicious apps from gaining control over your phone (If the user cannot press back or home, he might never be able to exit the app). The Home button is considered the user's "safe zone" and will always launch the user's configured home app.

The only exception to the above is any app configured as home replacement. Which means it has the following declared in its AndroidManifest.xml for the relevant activity:

<intent-filter>
   <action android:name="android.intent.action.MAIN" />
   <category android:name="android.intent.category.HOME" />
   <category android:name="android.intent.category.DEFAULT" />
</intent-filter>

When pressing the home button, the current home app's activity's onNewIntent will be called.

回答4:

I found that when I press the button HOME the onStop() method is called.You can use the following piece of code to monitor it:

@Override
    protected void onStop() 
    {
        super.onStop();
        Log.d(tag, "MYonStop is called");
        // insert here your instructions
    }

回答5:

KeyEvent.KEYCODE_HOME can NOT be intercepted.

It would be quite bad if it would be possible.

(Edit): I just see Nicks answer, which is perfectly complete ;)

回答6:

Using BroadcastReceiver

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // something
    // for home listen
    InnerRecevier innerReceiver = new InnerRecevier();
    IntentFilter intentFilter = new IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
    registerReceiver(innerReceiver, intentFilter);

}



// for home listen
class InnerRecevier extends BroadcastReceiver {

    final String SYSTEM_DIALOG_REASON_KEY = "reason";
    final String SYSTEM_DIALOG_REASON_HOME_KEY = "homekey";

    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (Intent.ACTION_CLOSE_SYSTEM_DIALOGS.equals(action)) {
            String reason = intent.getStringExtra(SYSTEM_DIALOG_REASON_KEY);
            if (reason != null) {
                if (reason.equals(SYSTEM_DIALOG_REASON_HOME_KEY)) {
                    // home is Pressed
                }
            }
        }
    }
}

回答7:

I have a simple solution on handling home button press. Here is my code, it can be useful:

public class LifeCycleActivity extends Activity {


boolean activitySwitchFlag = false;

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) 
{
    if(keyCode == KeyEvent.KEYCODE_BACK)
    {
        activitySwitchFlag = true;
        // activity switch stuff..
        return true;
    }
    return false;
}

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
}

@Override 
public void onPause(){
    super.onPause();
    Log.v("TAG", "onPause" );
    if(activitySwitchFlag)
        Log.v("TAG", "activity switch");
    else
        Log.v("TAG", "home button");
    activitySwitchFlag = false;
}

public void gotoNext(View view){
    activitySwitchFlag = true;
    startActivity(new Intent(LifeCycleActivity.this, NextActivity.class));
}

}

As a summary, put a boolean in the activity, when activity switch occurs(startactivity event), set the variable and in onpause event check this variable..

回答8:

use onPause() method to do what you want to do on home button.

回答9:

I also struggled with HOME button for awhile. I wanted to stop/skip a background service (which polls location) when user clicks HOME button.

here is what I implemented as "hack-like" solution;

keep the state of the app on SharedPreferences using boolean value

on each activity

onResume() -> set appactive=true

onPause() -> set appactive=false

and the background service checks the appstate in each loop, skips the action

IF appactive=false

it works well for me, at least not draining the battery anymore, hope this helps....

来源：https://stackoverflow.com/questions/4783960/call-method-when-home-button-pressed

标签

android

button

android-sdk-1.6