当应用程序移至背景时，如何更改活动，然后在恢复时再次更改活动？

Question

我的目标是使我的密码管理器应用程序的当前可见活动（例如Magenuactivity）在暂停应用程序时更改为空屏幕（因此，当应用程序在后台时，没有人可以看到密码），然后在恢复应用程序以供用户log时运行loginScreenactivity。返回。我使用 vokilam by vokilam来实现lifecycleobserver，而且我效果很好，但是我没有，但是我没有效果将意图传递给ApplifecyClelistener类的选项。我该如何克服这个问题？先感谢您。

applifecyclelistener.kt

import android.app.Application
import android.util.Log
import androidx.lifecycle.DefaultLifecycleObserver
import androidx.lifecycle.LifecycleOwner
import androidx.lifecycle.ProcessLifecycleOwner

class App : Application() {

    override fun onCreate() {
        super.onCreate()
        ProcessLifecycleOwner.get().lifecycle.addObserver(AppLifecycleListener())
    }
}

class AppLifecycleListener : DefaultLifecycleObserver {

    override fun onResume(owner: LifecycleOwner) {
        Log.i(null, "Resume")
    }

    override fun onStop(owner: LifecycleOwner) {
        Log.i(null, "Stop")
    }
}

mainmenuactivity.kt

class MainMenuActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setContentView(R.layout.activity_menu)

        supportActionBar?.hide()

        val goToPassGeneratorScreenButton = findViewById<Button>(R.id.goToPassGeneratorScreenButton)
        val goToPassCheckScreenButton = findViewById<Button>(R.id.goToPassCheckScreenButton)
        val addServicePasswordButton = findViewById<Button>(R.id.addServicePasswordButton)
        val updateServicePasswordButton = findViewById<Button>(R.id.updateServicePasswordButton)
        val updateMasterkKeyButton = findViewById<Button>(R.id.updateMasterKeyButton)

        goToPassGeneratorScreenButton.setOnClickListener {
            val intent = Intent(this, PassGeneratorActivity::class.java)
            startActivity(intent)
        }
        goToPassCheckScreenButton.setOnClickListener {
            val intent = Intent(this, PassViewerActivity::class.java)
            startActivity(intent)
        }

        addServicePasswordButton.setOnClickListener {
            val intent = Intent(this, PassCreatorActivity::class.java)
            startActivity(intent)
        }

        updateServicePasswordButton.setOnClickListener {
            val intent = Intent(this, PassEditorActivity::class.java)
            startActivity(intent)
        }

        updateMasterkKeyButton.setOnClickListener {
            val intent = Intent(this, MasterKeyEditorActivity::class.java)
            startActivity(intent)
        }
    }

    override fun onBackPressed() {
        moveTaskToBack(true)
    }

androidManifest.xml的片段

...
    <application
        android:name=".App"
...
    </application>