Android开发 - ActivityLifecycleCallbacks使用方法初探-优快云博客

ActivityLifecycleCallbacks是什么？

Application通过此接口提供了一套回调方法，用于让开发者对Activity的生命周期事件进行集中处理。

为什么用ActivityLifecycleCallbacks？

以往若需监测Activity的生命周期事件代码，你可能是这样做的，重写每一个Acivity的onResume()，然后作统计和处理：

   
    
   
@Override
protected void onResume() {
  super.onResume();
  //TODO 处理和统计代码
  Log.v(TAG, "onResume");
  Logger.v(TAG, "onResume");
  Logging.v(TAG, "onResume");
  ...
}

ActivityLifecycleCallbacks接口回调可以简化这一繁琐过程，在一个类中作统一处理

ActivityLifecycleCallbacks怎么用？

android.app.Application.ActivityLifecycleCallbacks
要求API 14+ （Android 4.0+）

继承Application

   
    
    public class BaseApplication extends Application

在AndroidManifest里起用自定义Application

   
    
    <application android:name=".global.BaseApplication"

重写Application的onCreate()方法，或在Application的无参构造方法内，调用Application.registerActivityLifecycleCallbacks()方法，并实现ActivityLifecycleCallbacks接口

   
    
   
public void onCreate() {
  super.onCreate();
  this.registerActivityLifecycleCallbacks(new ActivityLifecycleCallbacks() {
 
    @Override
    public void onActivityStopped(Activity activity) {
        Logger.v(activity, "onActivityStopped");
    }
 
    @Override
    public void onActivityStarted(Activity activity) {
        Logger.v(activity, "onActivityStarted");
    }
 
    @Override
    public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
        Logger.v(activity, "onActivitySaveInstanceState");
    }
 
    @Override
    public void onActivityResumed(Activity activity) {
        Logger.v(activity, "onActivityResumed");
    }
 
    @Override
    public void onActivityPaused(Activity activity) {
        Logger.v(activity, "onActivityPaused");
    }
 
    @Override
    public void onActivityDestroyed(Activity activity) {
        Logger.v(activity, "onActivityDestroyed");
    }
 
    @Override
    public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
        Logger.v(activity, "onActivityCreated");
    }
  });
};

运行结果(Logcat日志)

   
    
   
10-21 14:32:57.722: V/WelcomeActivity(8085): onActivityCreated
10-21 14:32:57.762: V/WelcomeActivity(8085): onActivityStarted
10-21 14:32:57.762: V/WelcomeActivity(8085): onActivityResumed
10-21 14:32:59.164: V/WelcomeActivity(8085): onActivityPaused
10-21 14:32:59.194: V/MainActivity(8085): onActivityCreated
10-21 14:32:59.224: V/MainActivity(8085): onActivityStarted
10-21 14:32:59.224: V/MainActivity(8085): onActivityResumed
10-21 14:32:59.735: V/WelcomeActivity(8085): onActivityStopped
10-21 14:32:59.735: V/WelcomeActivity(8085): onActivityDestroyed
10-21 14:33:06.502: V/MainActivity(8085): onActivityPaused
10-21 14:33:06.612: V/MainActivity(8085): onActivityStopped
10-21 14:33:06.612: V/MainActivity(8085): onActivityDestroyed

ActivityLifecycleCallbacks的拓展用法

本次初探仅尝试使用Log日志工具作简要测试，如需满足较复杂的统计或调试需求时，此法可能会大大减少插入代码量，提高效率
API仅在14+版本上提供此接口回调，Android 4.0以下系统如何使用？
API仅针对上述几个Activity的生命周期事件留出了接口回调，可能已无法满足日益过渡为使用Fragment的今日需求，如何在更大范围内应用LifecycleCallbacks？