Android 监听各个Acitivity的生命周期

在Application注册对该应用Activity的监听

package com.example.test.app;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.Application;
import android.os.Bundle;

public class MyApplication extends Application
{
@SuppressLint("NewApi") @Override
public void onCreate()
{
super.onCreate();
registerActivityLifecycleCallbacks(new ActivityLifecycleCallbacks()
{

@Override
public void onActivityStopped(Activity activity)
{
System.out.println("======>>>>>>" + activity.getClass().getCanonicalName() + " onActivityStopped");
}

@Override
public void onActivityStarted(Activity activity)
{
System.out.println("======>>>>>>" + activity.getClass().getCanonicalName() + " onActivityStarted");

}

@Override
public void onActivitySaveInstanceState(Activity activity, Bundle outState)
{
System.out.println("======>>>>>>" + activity.getClass().getCanonicalName() + " onActivitySaveInstanceState");

}

@Override
public void onActivityResumed(Activity activity)
{
System.out.println("======>>>>>>" + activity.getClass().getCanonicalName() + " onActivityResumed");

}

@Override
public void onActivityPaused(Activity activity)
{
System.out.println("======>>>>>>" + activity.getClass().getCanonicalName() + " onActivityPaused");

}

@Override
public void onActivityDestroyed(Activity activity)
{
System.out.println("======>>>>>>" + activity.getClass().getCanonicalName() + " onActivityDestroyed");

}

@Override
public void onActivityCreated(Activity activity, Bundle savedInstanceState)
{
System.out.println("======>>>>>>" + activity.getClass().getCanonicalName() + " onActivityCreated");
}
});
}
}

两个Activity

package com.example.test;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;

public class MainActivity extends Activity
{

@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
startActivity(new Intent(this, SecondActivity.class));
}
}

package com.example.test;

import android.app.Activity;
import android.os.Bundle;

public class SecondActivity extends Activity
{
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
}
}

打开应用MainActivity然后进入SecondActivity,生命周期的监听打印如下:

03-21 15:09:53.225: I/System.out(4289): ======>>>>>>com.example.test.MainActivity onActivityCreated
03-21 15:09:53.245: I/System.out(4289): ======>>>>>>com.example.test.MainActivity onActivityStarted
03-21 15:09:53.245: I/System.out(4289): ======>>>>>>com.example.test.MainActivity onActivityResumed
03-21 15:09:53.275: I/System.out(4289): ======>>>>>>com.example.test.MainActivity onActivityPaused
03-21 15:09:53.315: I/System.out(4289): ======>>>>>>com.example.test.SecondActivity onActivityCreated
03-21 15:09:53.315: I/System.out(4289): ======>>>>>>com.example.test.SecondActivity onActivityStarted
03-21 15:09:53.315: I/System.out(4289): ======>>>>>>com.example.test.SecondActivity onActivityResumed
03-21 15:09:53.590: I/System.out(4289): ======>>>>>>com.example.test.MainActivity onActivitySaveInstanceState
03-21 15:09:53.590: I/System.out(4289): ======>>>>>>com.example.test.MainActivity onActivityStopped

可以在通过监听各个Activity做一些统计性的工作，比如多少个Activity处于resume状态，统计Acitivity使用情况等。再比如每个Activity在每个onCreate时候将其放进集合，在要退出程序的时候，通过扫描集合，挨个finish()

square leakcanary工具即使用onActivityDestroyed回调+weakRefence+refrenceQueue判断Activity有没有泄露。（PS：这个是听别人说的，想想确实能做到）