公共静态变量和Android Activity生命周期管理 [英] Public static variables and Android activity life cycle management

问题描述

根据文档，Android 操作系统可以终止后台堆栈后面的活动.

According to the documentation the Android OS can kill the activity at the rear of the backstack.

例如，假设我有一个应用程序并打开主活动(我们称之为活动 A).在这个公共活动类中，我声明并初始化了一个公共静态变量(我们称之为foo").在活动 A 的 onCreate() 方法中，我更改了foo"的值.用户从活动 A 开始我的应用程序中称为活动 B 的另一个活动.活动 B 中使用变量foo".然后在用户导航到其他应用程序中的其他活动后暂停活动 B.最终，在发生内存短缺后，Activity A 和 Activity B 可以被杀死.在用户导航回我的应用程序后，它会重新启动(实际上是重新创建")活动 B.

So, say for example I have an app and open the Main Activity (let's call it Activity A). In this public activity class I declare and initialize a public static variable (let's call it "foo"). In Activity A's onCreate() method I then change the value of "foo." From Activity A the user starts another activity within my app called Activity B. Variable "foo" is used in Activity B. Activity B is then paused after the user navigates to some other activities in other apps. Eventually, after a memory shortage occurs, Activity A then Activity B can be killed. After the user navigates back to my app it restarts (actually "recreates") activity B.

发生了什么:

1. 此时变量foo"是否具有在活动 A 的 onCreate() 方法运行时为其设置的值?

1. Will variable "foo" at this point have the value that was set to it when Activity A's onCreate() method ran?

变量foo"不存在?

变量foo"存在，但现在是初始化值而不是活动 A 的 onCreate() 方法中设置的值?

Variable "foo" exists and but is now the initialized value and not the value set in Activity A's onCreate() method ?

推荐答案

如果进程被终止，那么所有静态变量将被重新初始化为它们的默认值.

If the process is killed then all static variables will be reinitialized to their default values.

因此您在活动 A 中设置的任何值都不会持久

So whatever value you have set in Activity A will not persist

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