小编vib*_*hor的帖子

我有一个以下布局的活动

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="horizontal" >

    <FrameLayout
        android:id="@+id/frameLayoutA"
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:layout_weight="1" >
    </FrameLayout>
    <FrameLayout
        android:id="@+id/frameLayoutB"
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:layout_weight="1" >
    </FrameLayout>
</LinearLayout>

在onCreate of activity中,我在frameLayoutA中加载Fragment_A,在frameLayoutB中加载Fragment_B.

public void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    fmA=(FrameLayout) findViewById(R.id.frameLayoutA);
    fmB=(FrameLayout) findViewById(R.id.frameLayoutB);

    fragA=new FragmentA();
    fragB=new FragmentB();
    fragC=new FragmentC();
    addFragmentsInActivity(R.id.frameLayoutA,fragA);
    addFragmentsInActivity(R.id.frameLayoutB,fragB);
}

public void addFragmentsInActivity(int id, Fragment fragment)
{
    FragmentManager fragmentManager = getFragmentManager();
    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
    fragmentTransaction.add(id, fragment);
    fragmentTransaction.commit();
}

使用菜单操作我想在frameLayoutA中加载Fragment_B,在frameLayoutB中加载Fragment_C.菜单操作是:

    removeFragmentsInActivity(R.id.frameLayoutB,fragB);
    addFragmentsInActivity(R.id.frameLayoutB,fragC);
    if(!fragB.isAdded()){
            Log.e("check", "fragB already removed from frameLayoutB");
        removeFragmentsInActivity(R.id.frameLayoutB,fragB);
        addFragmentsInActivity(R.id.frameLayoutA,fragB);
    }
    else{
        Log.e("check", "fragB …