Android性能优化第(九)篇---App启动速度优化之启动页设计

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在上篇文章Android性能优化第(八)篇---App启动速度优化之耗时检测处理说了应用启动的拦路虎在哪里,最后给出了优化思路,如果经过第一轮的优化之后,还是不满意的话,一般我们是做个启动页,因为启动页一般View的数量比较少,业务逻辑比较简单,启动就不太费劲。

一、设计思路

  • 常规启动页设计思路

通常点击桌面就会执行,Application中的逻辑,这部分的逻辑优化技巧在上篇介绍过,然后会跳入启动页SplashActivity,通常展示一个图片和logo,然后2或3秒后,并且SplashActivity里面可以去做一些MainActivity的数据的预加载,然后需要通过意图传到MainActivity。
优点:启动速度有所加快
缺点:最终还是要进入首页,在进入首页的时候,首页复杂的View渲染以及必须在UI线程执行的业务逻辑,仍然拖慢了启动速度。启动页简单执行快,首页复杂执行慢,前轻后重。

期待:能否在启动页的展示的同时,首页的View就能够被加载,首页的业务逻辑就能够被执行?

  • 优化的启动页的设计思路

为了在展示启动页的同时,也能渲染首页,把SplashActivity改成SplashFragment,应用程序的入口仍然是MainActivity,在MainActivity中先展示SplashFragment,当SplashFragment显示完毕后再将它remove,同时在SplashFragment的2S的友好时间内进行网络数据缓存,在窗口加载完毕后,我们加载activity_main的布局,考虑到这个布局有可能比较复杂,耽误View的解析时间,采用ViewStub的形式进行懒加载。这样一开始只要加载SplashFragment所展示的布局就Ok了。

二、实现

MainActivity .java

public class MainActivity extends FragmentActivity {

    private  MyHandler mHandler=new MyHandler(this);

    public static final String TAG="MainActivity";

    private ProgressBar mNetLoadingBar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Log.d(TAG,"onCreate");
        setContentView(R.layout.activity_main);
        final SplashFragment splashFragment = new SplashFragment();
        final ViewStub mainLayout = (ViewStub) findViewById(R.id.content_viewstub);
        //1、一上来首先显示启动页面
        FragmentManager supportFragmentManager = getSupportFragmentManager();
        if (supportFragmentManager != null) {
            FragmentTransaction fragmentTransaction = supportFragmentManager.beginTransaction();
            if (fragmentTransaction != null) {
                fragmentTransaction.replace(R.id.container, splashFragment);
                fragmentTransaction.commit();
            }
        }

        //2、如果主页有网络等耗时操作,可以现在就开始
        new Thread(new Runnable() {
            @Override
            public void run() {
                //耗时3500
                SystemClock.sleep(3000);
                mHandler.sendEmptyMessage(0);
            }
        }).start();

        //3、渲染完毕后,立刻加载主页布局
        getWindow().getDecorView().post(new Runnable() {
            @Override
            public void run() {
                Log.d(TAG," getWindow().getDecorView().post");
                View mainView = mainLayout.inflate();
                initView(mainView);
            }
        });

        //4、 启动页有动画,延迟一下,播放完动画,执行remove
        getWindow().getDecorView().post(new Runnable() {
            @Override
            public void run() {
                mHandler.postDelayed(new DelayRunnableImpl(MainActivity.this, splashFragment), 2000);
            }
        });
    }

    @Override
    protected void onResume() {
        super.onResume();
        Log.d(TAG,"onResume");
    }

    /**
     * 初始化主页View
     */
    private void initView(View pMainView) {
        if (pMainView != null) {
            mNetLoadingBar = (ProgressBar) pMainView.findViewById(R.id.progressbar);
            mNetLoadingBar.setVisibility(View.VISIBLE);
        }
    }


    private static class MyHandler extends Handler {

        private WeakReference<MainActivity> wRef;

        private MyHandler(MainActivity pActivity) {
            this.wRef = new WeakReference<MainActivity>(pActivity);
        }

        @Override
        public void handleMessage(Message msg) {
            MainActivity mainActivity = wRef.get();
            if (mainActivity != null) {
                mainActivity.mNetLoadingBar.setVisibility(View.GONE);
            }
        }
    }

    private class DelayRunnableImpl implements Runnable {
        WeakReference<Context> contextWref;
        WeakReference<Fragment> fragmentWref;

        private DelayRunnableImpl(Context pContext, Fragment pFragment) {
            this.contextWref = new WeakReference<>(pContext);
            this.fragmentWref = new WeakReference<>(pFragment);
        }

        @Override
        public void run() {
            FragmentActivity context = (FragmentActivity) contextWref.get();
            if (context != null) {
                FragmentManager supportFragmentManager = context.getSupportFragmentManager();
                if (supportFragmentManager != null) {
                    FragmentTransaction fragmentTransaction = supportFragmentManager.beginTransaction();
                    SplashFragment fragment = (SplashFragment) fragmentWref.get();
                    if (fragment != null) {
                        fragmentTransaction.remove(fragment);
                        fragmentTransaction.commit();
                    }
                }
            }
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (mHandler != null) {
            mHandler.removeCallbacksAndMessages(null);
        }
    }

}

SplashFragment .java

public class SplashFragment extends Fragment {

    public SplashFragment() {

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View ret = inflater.inflate(R.layout.fragment_splash, container, false);
        initView(ret);
        return ret;
    }

    private void initView(View ret) {
        if (ret != null) {
            ImageView imageView = (ImageView) ret.findViewById(R.id.laucher_logo);
            playAnimator(imageView);
        }
    }

    private void playAnimator(ImageView pView) {
        if (pView != null) {
            PropertyValuesHolder pvhA = PropertyValuesHolder.ofFloat("alpha", 1f, 0.7f, 0.1f);
            //  PropertyValuesHolder pvhR= PropertyValuesHolder.ofFloat("rotationX", 0.0F, 360.0F);
            ObjectAnimator.ofPropertyValuesHolder(pView, pvhA).setDuration(2000).start();
        }
    }
}

activity_mian.xml


<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="zhangwan.wj.com.myshare.activity.MainActivity">

    <ViewStub
        android:id="@+id/content_viewstub"
        android:layout="@layout/main_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <FrameLayout
        android:id="@+id/container"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</RelativeLayout>

fragment.xml

<FrameLayout 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"
    tools:context="zhangwan.wj.com.myshare.fragment.SplashFragment">

    <ImageView
        android:id="@+id/laucher_logo"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@drawable/launch" />

</FrameLayout>

main_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@drawable/migu_home"
        android:contentDescription="@string/app_name" />

    <ProgressBar
        android:id="@+id/progressbar"
        android:indeterminateDrawable="@drawable/progress_bar"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_gravity="center" />
</FrameLayout>

效果怎么样呢?

看一下启动时间

C:\Users\wangjing>adb shell am start -W zhangwan.wj.com.myshare/zhangwan.wj.com.myshare.activity.MainActivity
Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] cmp=zhangwan.wj.com.myshare/.activity.MainActivity }
Status: ok
Activity: zhangwan.wj.com.myshare/.activity.MainActivity
ThisTime: 683
TotalTime: 683
Complete

还是挺不错的吧。

参考链接:请不要滥用SharedPreference https://zhuanlan.zhihu.com/p/22913991
Please accept mybest wishes for your happiness and success !

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