Application監聽activity的生命週期

在Application裏監聽activity的生命週期變化，代碼如下：

package com.test.proj;

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



public class MyLifecycleHandler implements Application.ActivityLifecycleCallbacks {
    private static int mVisible;
    private static int mForeground;

    @Override
    public void onActivityCreated(Activity activity, Bundle savedInstanceState) {

    }

    @Override
    public void onActivityStarted(Activity activity) {
        ++mVisible;

        if (isApplicationVisible()){

        }
    }

    @Override
    public void onActivityResumed(Activity activity) {
        ++mForeground;

    }

    @Override
    public void onActivityPaused(Activity activity) {
        --mForeground;

    }

    @Override
    public void onActivityStopped(Activity activity) {
        --mVisible;

        if (!isApplicationVisible()){

        }
    }

    @Override
    public void onActivityDestroyed(Activity activity) {

    }

    @Override
    public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
    }

    public static boolean isApplicationVisible() {
        return mVisible > 0;
    }

    public static boolean isApplicationInForeground() {
        // 當所有 Activity 的狀態中處於 mForeground 的大於 0 狀態的，即可認爲有Activity處於前臺狀態中
        return mForeground > 0;
    }
}

在app的application的onCreate裏註冊一下就可以了

public class MyApplication extends Application {



    @Override
    public void onCreate() {
        super.onCreate();

        registerActivityLifecycleCallbacks(new MyLifecycleHandler());

    }
}

就可以了。