Android系统叠加层未在我的应用外显示

Question

我需要在任何正在运行的应用程序之上显示系统覆盖窗口.它工作正常,但只有当我的应用程序的活动在前台时.这是我使用的代码:

params = new WindowManager.LayoutParams(
                    WindowManager.LayoutParams.WRAP_CONTENT,
                    WindowManager.LayoutParams.WRAP_CONTENT,
                    WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY,
                    WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE | 
                    WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE |
                    WindowManager.LayoutParams.FLAG_DIM_BEHIND |
                    WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON | 
                    WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED |
                    WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON |
                    WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD,
                    PixelFormat.TRANSLUCENT);

params.gravity = Gravity.CENTER | Gravity.TOP;
params.dimAmount = 0.3f;
wm = (WindowManager) ctx.getSystemService(Context.WINDOW_SERVICE);

    mainAlertView = View.inflate(ctx, R.layout.system_alert_view, null);

    wm.addView(mainAlertView, params);

添加到WindowManager的视图包含空的LinearLayout,我在运行时添加了子视图:

    mainAlertLayout.addView(childView);

清单xml已SYSTEM_ALERT_WINDOW定义权限:

<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>

当我的活动在前台运行时,这一切都很有效.只要我切换到任何其他应用程序或主屏幕,就不会显示叠加层.我调试了代码,它确实在运行wm.addView(),它没有抛出任何异常.我还玩过LayoutParams标志(删除了KEEP_SCREEN_ON和相关的等),但没有任何区别.

Android 4.4.2 fwiw

Answer 1

您需要创建一个service以便在应用程序关闭时保持系统覆盖(警报)显示.

创建一个简单的服务,我将调用as FloatingService,它将在调用时显示覆盖(警报)onStartCommand.返回START_STICKY以使服务在后台运行.

    public class FloatingService extends Service {
      private WindowManager windowManager;
      private View floatingView;

     WindowManager.LayoutParams params;
    @Override
     public IBinder onBind(Intent intent) {
        return null;
      }

     @Override
     public int onStartCommand(Intent intent, int flag, int startId){
      // show the alert her
      windowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
       // use your custom view here
        floatingView = View.inflate(getBaseContext(),R.layout.floating_layout,null);            //floatingView.setOnTouchListener(mOnTouchListener);
        params = new WindowManager.LayoutParams(
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.TYPE_PHONE,
                WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD,
                PixelFormat.TRANSLUCENT);
           params.gravity = Gravity.CENTER | Gravity.CENTER;
        // add the view to window manger
        windowManager.addView(floatingView, params);
      return START_STICKY;
     }
 }

向视图添加侦听器,以便在需要时关闭叠加层(警报)

      floatingView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                windowManager.removeView(floatingView);
                floatingView = null;
            }
        });

最后,在清单中注册服务

 <service android:name="com.example.app.services.FloatingService" />

和System Alert许可

 <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>