ActivityLifeCycleCallbacks
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？
在自定义的Application中的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");
}
});
};
Log:
V/OneActivity: onActivityCreated
V/OneActivity: onActivityStarted
V/OneActivity: onActivityResumed
V/OneActivity: onActivityPaused
V/MainActivity: onActivityCreated
V/MainActivity: onActivityStarted
V/MainActivity: onActivityResumed
V/OneActivity: onActivityStopped
V/OneActivity: onActivityDestroyed
V/MainActivity: onActivityPaused
V/MainActivity: onActivityStopped
V/MainActivity: onActivityDestroyed
注意
ActivityLifeCycleCallbacks在API>=14上才可以调用。
兼容API<14
- 自己写一个ActivityLifeCycleCallbacks接口：
public interface ActivityLifecycleCallbacks{
public void onActivityStopped(Activity activity);
public void onActivityStarted(Activity activity);
public void onActivitySaveInstanceState(Activity activity, Bundle outState);
public void onActivityResumed(Activity activity);
public void onActivityPaused(Activity activity);
public void onActivityDestroyed(Activity activity);
public void onActivityCreated(Activity activity, Bundle savedInstanceState);
}
- 在Application中实现接口：
public class MyApplication extends Application implements my.package.ActivityLifecycleCallbacks{
@Override
public void onCreate() {
super.onCreate();
}
@Override
public void onActivityStopped(Activity activity) {
Log.i("Tracking Activity Stopped", activity.getLocalClassName());
}
@Override
public void onActivityStarted(Activity activity) {
Log.i("Tracking Activity Started", activity.getLocalClassName());
}
@Override
public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
Log.i("Tracking Activity SaveInstanceState", activity.getLocalClassName());
}
@Override
public void onActivityResumed(Activity activity) {
Log.i("Tracking Activity Resumed", activity.getLocalClassName());
}
@Override
public void onActivityPaused(Activity activity) {
Log.i("Tracking Activity Paused", activity.getLocalClassName());
}
@Override
public void onActivityDestroyed(Activity activity) {
Log.i("Tracking Activity Destroyed", activity.getLocalClassName());
}
@Override
public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
Log.i("Tracking Activity Created", activity.getLocalClassName());
}
}
- 写基类：
public class BaseActivity extends Activity {
protected MyApplication nMyApplication;
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
nMyApplication = (MyApplication) getApplication();
nMyApplication.onActivityCreated(this, savedInstanceState);
}
protected void onResume() {
// TODO Auto-generated method stub
nMyApplication.onActivityResumed(this);
super.onResume();
}
@Override
protected void onPause() {
// TODO Auto-generated method stub
nMyApplication.onActivityPaused(this);
super.onPause();
}
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
nMyApplication.onActivityDestroyed(this);
super.onDestroy();
}
@Override
protected void onStart() {
nMyApplication.onActivityStarted(this);
super.onStart();
}
@Override
protected void onStop() {
nMyApplication.onActivityStopped(this);
super.onStop();
}
@Override
protected void onSaveInstanceState(Bundle outState) {
nMyApplication.onActivitySaveInstanceState(this, outState);
super.onSaveInstanceState(outState);
}
}
- 所有的类集成这个基类：
public class MainActivity extends BaseActivity{
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}
