android - Is there an onBackPressed() alternative for a service?

Question

I know that services cannot implement Back key press and I understand the rationale. But there is an app called SideBar (on Play Store) that reacts to back key presses. It is a service that adds a view as system overlay and removes the view when the back key is pressed. Can anybody explain how this is done?

Here is another app that does it well. I have scoured the web, but have not found a solution to this problem. Any ideas?

Answer 1

它可能是使用系统警报窗口完成的 - 因此该服务创建并管理一个添加到窗口管理器的窗口，该窗口管理器上设置了自定义回调。

Answer 2

这 是在服务中添加视图的好例子，如果你想在服务中使用监听器，你也可以使用。

我也在寻找服务中的监听器实现，终于找到了。

记得添加权限

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

并添加您的服务类

<application>
.
 .
  <service android:name=".YourServiceClass"></service>
 .
.
</application>

在 AndroidManifest.xml 中。