首先，我有两个活动：启动和MainActivity（只支持纵向）。在MainActivity，我有很多的片段用幻灯片菜单。我想保持当前片段，当用户离开MainActivity。这里是我的尝试：

First, I have two activities: Splash and MainActivity ( only support portrait). In MainActivity, I have many fragments use Slide menu. I want to keep current fragment when user leave MainActivity. Here is my try:

  int currentFragment  = 0;

  public void onCreate(Bundle savedInstanceState) {
  if (savedInstanceState != null) {
        currentFragment = savedInstanceState.getInt(CURRENT_FRAGMENT_KEY, 0);
        switchContent(currentFragment);
    } else {
          // change fragment by index
        switchContent(0);
    }
 }

  @Override
protected void onSaveInstanceState(Bundle outState) {
    outState.putInt(CURRENT_FRAGMENT_KEY, currentFragment);
    Log.d("onSaveInstanceState" ," current fragment" + currentFragment);
    super.onSaveInstanceState(outState);
}

我的清单：

   <activity
        android:name="com.appiphany.auskills.activity.SplashActivity"
        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=".activity.MainActivity" 
        android:screenOrientation="portrait" />    

一切都很好，当我建立我的应用程序与调试的关键：preSS Home键，然后再返回到应用程序，它打开previous片段。但是，当我建立在释放模式（用我的私钥，我不使用 ProGuard的）的MainActivity，preSS HOME键，然后打开应用程序再次，从SplashActivity 。我不知道这个奇怪的问题。我的事件试试这个，但它并不能帮助：

Everything is fine when I build my app with debug key: press Home button, then back to the app, it open previous fragment. But when I build on release mode (use my private key, I don't use proguard), press HOME button in MainActivity, then open app again, it starts from SplashActivity. I have no idea with this strange issue. I event try this one but it doesn't help:

   @Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);
    currentFragment = savedInstanceState.getInt(CURRENT_FRAGMENT_KEY, 0);
        switchContent(currentFragment);     
} 

有没有什么想法？

Is there any ideas?

更新：我发现了另一个奇怪的：当我从APK文件安装此问题只发生。安装后，手机会询问2个选项：完成或打开。如果我preSS 打开，这个问题发生了。当我杀了通过任务管理器应用程序，然后重新打开，它正常工作。

Update: I found another strange one: this issues only occurred when I install it from apk file. After install, phone will ask 2 options: Done or Open. If I press open, this issues happened. When I kill app by task manager, then open again, it work correctly.

推荐答案

问题已得到修复使用 FLAG_ACTIVITY_NEW_TASK 时，导航距离Splash主活动。我不知道为什么它可以在调试模式下工作（重现从APK像释放模式安装）。这是我的可行$ C $下任何人有同样的问题：

Issue has been fixed by using FLAG_ACTIVITY_NEW_TASK when navigate from Splash to Main activity. I just wonder why it can work in debug mode (Reproduce install from apk like release mode). Here is my workable code for anyone has same issues:

 Intent intent = new Intent(SplashActivity.this, MainActivity.class);
 intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
 finish();
 startActivity(intent);

更新：非常感谢大卫·瓦瑟，所以正确答案应该是这样的：

Update: many thanks to David Wasser, so the right answer should like this:

// SplashActivity
 if(!isTaskRoot()) {
    finish();
    return;
 }

参考：Re-launch活动的Home键，不过......只有第一次的