Android中ActivityLifecycleCallbacks監聽Activity們的生命週期
阿新 • • 發佈：2018-12-31
如果你還在Activity的宣告周期函式（onCreate、onStart）列印log來看activity的宣告週期，那麼你就out了！
今天樓主叫你用ActivityLifecycleCallbacks來監聽activity們的宣告週期。
接下來上程式碼：
AndroidManifest.xml：
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.lxxcaroline.applicationtest"> <application android:name="com.example.lxxcaroline.test.MyApplication" android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme"> <activity android:name=".MainActivity" android:label="@string/app_name"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <activity android:name=".SecondActivity" android:label="secondActivity"> </activity> </application> </manifest>
MainActivity.java：
package com.example.lxxcaroline.applicationtest; import android.content.Intent; import android.os.Bundle; import android.support.v7.app.ActionBarActivity; import android.util.Log; import android.view.View; import android.widget.Button; public class MainActivity extends ActionBarActivity { private static final String TAG="ApplicationTest"; private Button button; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Log.d(TAG,"MainActivity is created successfully."); button=(Button)findViewById(R.id.btn); button.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent=new Intent(MainActivity.this,SecondActivity.class); startActivity(intent); } }); } }
SecondActivity.java：
activity_main.xml：package com.example.lxxcaroline.applicationtest; import android.app.Activity; import android.os.Bundle; /** * Created by LxxCaroline on 2015/5/4. */ public class SecondActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.layout); } }
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".MainActivity">
<Button
android:id="@+id/btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="button"/>
</RelativeLayout>
layout.xml：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".MainActivity">
<TextView
android:text="@string/hello_world"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>MyApplication.java：
package com.example.lxxcaroline.test;
import android.app.Activity;
import android.app.Application;
import android.os.Bundle;
import android.util.Log;
import com.example.lxxcaroline.applicationtest.MainActivity;
import com.example.lxxcaroline.applicationtest.SecondActivity;
/**
* Created by LxxCaroline on 2015/5/3.
*/
public class MyApplication extends Application {
private static final String TAG = "MyApplication";
//宣告一個監聽Activity們生命週期的介面
private ActivityLifecycleCallbacks activityLifecycleCallbacks = new ActivityLifecycleCallbacks() {
/**
* application下的每個Activity宣告週期改變時，都會觸發以下的函式。
*/
@Override
public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
//如何區別引數中activity代表你寫的哪個activity。
if (activity.getClass() == MainActivity.class)
Log.d(TAG, "MainActivityCreated.");
else if(activity.getClass()== SecondActivity.class)
Log.d(TAG, "SecondActivityCreated.");
}
@Override
public void onActivityStarted(Activity activity) {
Log.d(TAG, "onActivityStarted.");
}
@Override
public void onActivityResumed(Activity activity) {
Log.d(TAG, "onActivityResumed.");
}
@Override
public void onActivityPaused(Activity activity) {
Log.d(TAG, "onActivityPaused.");
}
@Override
public void onActivityStopped(Activity activity) {
Log.d(TAG, "onActivityStopped.");
}
@Override
public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
}
@Override
public void onActivityDestroyed(Activity activity) {
Log.d(TAG, "onActivityDestroyed.");
}
};
/**
* onCreate是一個回撥介面，android系統會在應用程式啟動的時候，在任何應用程式元件（activity、服務、
* 廣播接收器和內容提供者）被建立之前呼叫這個介面。
* 需要注意的是，這個方法的執行效率會直接影響到啟動Activity等的效能，因此此方法應儘快完成。
* 最後在該方法中，一定要記得呼叫super.onCreate()，否則應用程式將會報錯。
*/
@Override
public void onCreate() {
super.onCreate();
//註冊自己的Activity的生命週期回撥介面。
registerActivityLifecycleCallbacks(activityLifecycleCallbacks);
}
@Override
public void onTerminate() {
//登出這個介面。
unregisterActivityLifecycleCallbacks(activityLifecycleCallbacks);
super.onTerminate();
}
}
跑起來的log，步驟：進入程式，點選首頁的按鈕，進入第二個頁面，然後依次返回到桌面上，log如下：
05-04 10:28:03.489 24885-24885/com.example.lxxcaroline.applicationtest D/MyApplication﹕ MainActivityCreated.
05-04 10:28:03.639 24885-24885/com.example.lxxcaroline.applicationtest D/ApplicationTest﹕ MainActivity is created successfully.
05-04 10:28:03.639 24885-24885/com.example.lxxcaroline.applicationtest D/MyApplication﹕ onActivityStarted.
05-04 10:28:03.649 24885-24885/com.example.lxxcaroline.applicationtest D/MyApplication﹕ onActivityResumed.
05-04 10:28:33.361 24885-24885/com.example.lxxcaroline.applicationtest D/MyApplication﹕ onActivityPaused.
05-04 10:28:33.391 24885-24885/com.example.lxxcaroline.applicationtest D/MyApplication﹕ SecondActivityCreated.
05-04 10:28:33.411 24885-24885/com.example.lxxcaroline.applicationtest D/MyApplication﹕ onActivityStarted.
05-04 10:28:33.411 24885-24885/com.example.lxxcaroline.applicationtest D/MyApplication﹕ onActivityResumed.
05-04 10:28:33.781 24885-24885/com.example.lxxcaroline.applicationtest D/MyApplication﹕ onActivityStopped.
05-04 10:28:36.835 24885-24885/com.example.lxxcaroline.applicationtest D/MyApplication﹕ onActivityPaused.
05-04 10:28:36.875 24885-24885/com.example.lxxcaroline.applicationtest D/MyApplication﹕ onActivityStarted.
05-04 10:28:36.875 24885-24885/com.example.lxxcaroline.applicationtest D/MyApplication﹕ onActivityResumed.
05-04 10:28:37.205 24885-24885/com.example.lxxcaroline.applicationtest D/MyApplication﹕ onActivityStopped.
05-04 10:28:37.205 24885-24885/com.example.lxxcaroline.applicationtest D/MyApplication﹕ onActivityDestroyed.
05-04 10:28:38.627 24885-24885/com.example.lxxcaroline.applicationtest D/MyApplication﹕ onActivityPaused.
05-04 10:28:39.177 24885-24885/com.example.lxxcaroline.applicationtest D/MyApplication﹕ onActivityStopped.
05-04 10:28:39.177 24885-24885/com.example.lxxcaroline.applicationtest D/MyApplication﹕ onActivityDestroyed.