以上所有的答案都非常好。但是存在内存泄漏的问题。 这个问题在Android社区通常被称为“泄露活动”。这到底是什么意思呢?

当配置发生变化时，比如方向变化，Android会销毁Activity并重新创建它。通常，垃圾收集器只会清除旧Activity实例的已分配内存，一切正常。

“泄漏一个活动”指的是垃圾收集器无法清除旧活动实例的已分配内存的情况，因为它被(强)引用于一个活动实例外的对象。每个Android应用程序都分配了特定数量的内存。当垃圾回收器不能释放未使用的内存时，应用程序的性能将逐渐下降，最终崩溃并出现OutOfMemory错误。

如何确定应用程序是否泄漏内存?最快的方法是在Android Studio中打开内存选项卡，并在改变方向时注意分配的内存。 如果分配的内存一直在增加而不减少，那么就有内存泄漏。

1.当用户改变方向时内存泄漏。

首先，你需要在布局资源splashscreen.xml文件中定义启动画面

启动画面活动的示例代码。

public class Splash extends Activity {
 // 1. Create a static nested class that extends Runnable to start the main Activity
    private static class StartMainActivityRunnable implements Runnable {
        // 2. Make sure we keep the source Activity as a WeakReference (more on that later)
        private WeakReference mActivity;

        private StartMainActivityRunnable(Activity activity) {
         mActivity = new WeakReference(activity);
        }

        @Override
        public void run() {
         // 3. Check that the reference is valid and execute the code
            if (mActivity.get() != null) {
             Activity activity = mActivity.get();
             Intent mainIntent = new Intent(activity, MainActivity.class);
             activity.startActivity(mainIntent);
             activity.finish();
            }
        }
    }

    /** Duration of wait **/
    private final int SPLASH_DISPLAY_LENGTH = 1000;

    // 4. Declare the Handler as a member variable
    private Handler mHandler = new Handler();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(icicle);
        setContentView(R.layout.splashscreen);

        // 5. Pass a new instance of StartMainActivityRunnable with reference to 'this'.
        mHandler.postDelayed(new StartMainActivityRunnable(this), SPLASH_DISPLAY_LENGTH);
    }

    // 6. Override onDestroy()
    @Override
    public void onDestroy() {
     // 7. Remove any delayed Runnable(s) and prevent them from executing.
     mHandler.removeCallbacksAndMessages(null);

     // 8. Eagerly clear mHandler allocated memory
     mHandler = null;
    }
}

欲了解更多信息，请点击此链接

这是完整的代码

SplashActivity.java

public class SplashActivity extends AppCompatActivity {

private final int SPLASH_DISPLAY_DURATION = 1000;

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


    new Handler().postDelayed(new Runnable(){
        @Override
        public void run() {

            Intent mainIntent = new Intent(SplashActivity.this,MainActivity.class);
            SplashActivity.this.startActivity(mainIntent);
            SplashActivity.this.finish();
        }
    }, SPLASH_DISPLAY_DURATION);
}}

在drawables中创建bg_splash.xml

<?xml version="1.0" encoding="utf-8"?><layer-list xmlns:android="http://schemas.android.com/apk/res/android">

<item
    android:drawable="@color/app_color"/>

<item>
    <bitmap
        android:gravity="center"
        android:src="@drawable/ic_in_app_logo_big"/>
</item></layer-list>

在styles.xml中创建一个自定义主题

<style name="SplashTheme" parent="Theme.AppCompat.NoActionBar">
    <item name="android:windowBackground">@drawable/bg_splash</item>
</style>

最后在AndroidManifest.xml中指定活动的主题

<activity
        android:name=".activities.SplashActivity"
        android:label="@string/app_name"
        android:screenOrientation="portrait"
        android:theme="@style/SplashTheme">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

欢呼。

另一种方法是使用CountDownTimer实现

@Override
public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.splashscreen);

 new CountDownTimer(5000, 1000) { //5 seconds
      public void onTick(long millisUntilFinished) {
          mTextField.setText("seconds remaining: " + millisUntilFinished / 1000);
      }

     public void onFinish() {
          startActivity(new Intent(SplashActivity.this, MainActivity.class));
          finish();
     }

  }.start();
}

     - Add in SplashActivity 

   public class SplashActivity extends Activity {

       private ProgressBar progressBar;
       int i=0;
       Context context;
       private GoogleApiClient googleApiClient;

       @Override
       protected void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
           setContentView(R.layout.activity_splash);
           context = this;

           new Handler().postDelayed(new Runnable() {
               @Override
               public void run() {
                   startActivity(new Intent(Splash.this, LoginActivity.class));
                   finish();
               }
           }, 2000);

       }

   }

  - Add in activity_splash.xml

   <RelativeLayout
   xmlns:android="http://schemas.android.com/apk/res/android"
       xmlns:tools="http://schemas.android.com/tools"
       xmlns:custom="http://schemas.android.com/apk/res-auto"
       android:background="@color/colorAccent"
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       tools:context=".Splash">

       <ImageView
           android:id="@+id/ivLogo"
           android:layout_width="match_parent"
           android:layout_height="match_parent"
           android:src="@mipmap/icon_splash"
           android:layout_centerHorizontal="true"
           android:layout_centerVertical="true"/>


       <ProgressBar
           android:id="@+id/circle_progress"
           style="?android:attr/progressBarStyleHorizontal"
           android:layout_width="fill_parent"
           android:layout_height="wrap_content"
           android:layout_alignParentBottom="true"
           android:layout_marginBottom="5dp"
           android:max="100"
           android:progressTint="@color/green"
           android:visibility="visible" />

   </RelativeLayout>

  - Add in AndroidManifest.xml

    <activity android:name="ex.com.SplashActivity">
               <intent-filter>
                   <action android:name="android.intent.action.MAIN" />

                   <category android:name="android.intent.category.LAUNCHER" />
               </intent-filter>
           </activity>

这是我所见过的关于启动画面的最好的帖子:http://saulmm.github.io/avoding-android-cold-starts

Saúl Molinero介绍了两种不同的启动画面选项:利用窗口背景动画进入初始屏幕和显示占位符UI(这是谷歌目前在大多数应用程序中使用的流行选择)。

每当我需要考虑冷启动时间和避免由于长启动时间而导致用户流失时，我都会参考这篇文章。

希望这能有所帮助!

Create an Activity SplashScreen.java public class SplashScreen extends Activity { protected boolean _active = true; protected int _splashTime = 3000; // time to display the splash screen in ms @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.splashscreen); Thread splashTread = new Thread() { @Override public void run() { try { int waited = 0; while (_active && (waited < _splashTime)) { sleep(100); if (_active) { waited += 100; } } } catch (Exception e) { } finally { startActivity(new Intent(SplashScreen.this, MainActivity.class)); finish(); } }; }; splashTread.start(); } } splashscreen.xml will be like this <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="600px" android:layout_height="1024px" android:background="#FF0000"> </RelativeLayout>