Service with Overlay - catch back button press

问题

How can i do that?

Current solution

I launch a transparent activity, that catches the back press, forwards it to my service and closes itself afterwards. But this activity will be visible in the current running activities and therefore it's not a very beautiful solution.

Solutions seen

I've seen an app that does catch the back press in a service - without an activity that catches the back press. If I show the current running activities, there is nothing from this app.

Question

How can this be done? I've read so many threads that say, this is not possible, but I can see, that there are apps that achieve that somehow...

回答1:

I think I found out how it works... DON'T USE WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE in your overlays views + overwrite the dispatchKeyEvent of your view:

 @Override
public boolean dispatchKeyEvent(KeyEvent event)
{
    if (event.getKeyCode() == KeyEvent.KEYCODE_BACK)
    {
        // handle back press
        // if (event.getAction() == KeyEvent.ACTION_DOWN)
        return true;
    }
    return super.dispatchKeyEvent(event);
}

回答2:

I found solution for this issue,It's working good.

public class MyFooterService extends Service{
View myview;
WindowManager wm;
FrameLayout wrapper;
public MyFooterService() {

}
 @Override
public void onCreate() {
    Log.d(TAG, "onCreate called");
    LayoutInflater li = (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);
    wm = (WindowManager) getSystemService(WINDOW_SERVICE);
    final WindowManager.LayoutParams params = new WindowManager.LayoutParams(
            WindowManager.LayoutParams.MATCH_PARENT,
            90,  //height of ur layout
            WindowManager.LayoutParams.TYPE_PHONE,
            0,
            PixelFormat.TRANSLUCENT);

    params.gravity = Gravity.BOTTOM ;
    params.x = 0;
    params.y = 0;
   wrapper = new FrameLayout(this) {
        @Override
        public boolean dispatchKeyEvent(KeyEvent event) {
            if (event.getKeyCode()==KeyEvent.KEYCODE_BACK) {
              // handle the back button code;
             return true;
            }
          return super.dispatchKeyEvent(event);
        }
       //if pressed home key,
      public void onCloseSystemDialogs(String reason) {
            //The Code Want to Perform.
            System.out.println("System dialog " + reason);
            if (reason.equals("homekey")) {
                // handle home button 
            }
        }

     };
   myview = li.inflate(R.layout.my_footer, wrapper);   // here set into your own layout
   wm.addView(myview, params);

}
}

回答3:

If you have an overlay window attached in a WindowManager in your service, put your view the attribute setFocusableInTouchMode(true), and put a key listener. You'll receive key events, like in this example:

view.setFocusableInTouchMode(true);
view.setOnKeyListener(new View.OnKeyListener() {
    @Override
    public boolean onKey(View v, int keyCode, KeyEvent event) {
        if(keyCode == KeyEvent.KEYCODE_BACK) {
            stopSelf();
            return true;
        }
        return false;
    }
});

Edited, I didn't use good stackoverflow account

回答4:

You can catch the back button click event. For this you need to create container class of your OverlayView. For example: create class Overlay which will extends some ViewGroup class. Than, in the class, inflate your xml layout and add it to your Overlay.class ViewGroup. Than in Overlay.class override method dispatchKeyEvent(KeyEvent event). That's all!

class Overlay extends FrameLayout{
  
  public Overlay(@NonNull Context context) {
        super(new ContextThemeWrapper(context, R.style.AppTheme));

        initView();
    }
    
    private void initView() {
      //inflate your xml here
      //than do: this.addView(<inflated view>);
      //And in the end add your Overlay to WindowManager (in Service class of course).
    }
    
     @Override
    public boolean dispatchKeyEvent(KeyEvent event) {
        if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
            //do staff here
            // and return True!
            return true;
        }
        return super.dispatchKeyEvent(event);
    }
}

来源：https://stackoverflow.com/questions/31462119/service-with-overlay-catch-back-button-press