退出 App ( ActivityLifecycleCallbacks )

最完美的退出 APP 的方式是储存所有已打开的 Activity, 在退出的时候销毁

储存所有已打开的 Activity 最简单的方式就是在 App 里注册 ActivityLifecycleCallbacks, 通过 onActivityCreated 方法提供的 Activity 来存储, 通过 onActivityDestroyed 来销毁

代码如下:

import android.app.Activity
import android.app.Application
import android.os.Bundle
class App : Application() {
    override fun onCreate() {
        super.onCreate()
        registerActivityLifecycleCallbacks(activityLifecycleCallbacksImp)
    }
    class ActivityLifecycleCallbacksImp : Application.ActivityLifecycleCallbacks{
        private val acts = arrayListOf<Activity>()
        override fun onActivityCreated(activity: Activity, savedInstanceState: Bundle?) {
            acts.add(activity)
        }
        override fun onActivityDestroyed(activity: Activity) {
            acts.remove(activity)
        }
        fun exitApp() {
            acts.forEach { 
                it.finish()
            }
        }
        override fun onActivityStarted(activity: Activity) = Unit
        override fun onActivityResumed(activity: Activity) = Unit
        override fun onActivityPaused(activity: Activity) = Unit
        override fun onActivityStopped(activity: Activity) = Unit
        override fun onActivitySaveInstanceState(activity: Activity, outState: Bundle) = Unit
    }
    companion object {
        val activityLifecycleCallbacksImp by lazy {
            ActivityLifecycleCallbacksImp()
        }
        fun exitApp() {
            activityLifecycleCallbacksImp.exitApp()
        }
    }
}

使用方式:

// kotlin
App.exitApp()
// java
App.Companion.exitApp();