Android Layout nullpointerException

Question

我有一个非常奇怪的例外!首先我引用相对布局,然后我尝试获取其可见性状态,但活动崩溃并在getVisibilty()时抛出NullPointerException ; 我不知道为什么!,我花了很多时间试图找出问题,但我不能!,这是我的活动代码:

    setContentView(R.layout.main3d_activity);
    RelativeLayout optionLayout;
    optionLayout = (RelativeLayout) findViewById(R.id.main_optionLayout);
    int vis= optionLayout.getVisibility();

main3d_activity代码:

    <?xml version="1.0" encoding="utf-8"?> 
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/MainLayout"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <include
        android:id="@+id/include_headerbar"
        android:layout_width="fill_parent"
        android:layout_height="60dp"
        layout="@layout/headerbar_layout" />
    <include
        android:id="@+id/include_footerbar"
        android:layout_width="fill_parent"
        android:layout_height="60dp"
        android:layout_alignParentBottom="true"
        layout="@layout/footerbar_layout" />

    <ViewFlipper
        android:id="@+id/vf"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@+id/include_footerbar"
        android:layout_below="@+id/include_headerbar" >

        <include
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            layout="@layout/container_mainlayout" />

        <include
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            layout="@layout/living_layout" />

        <include
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            layout="@layout/bedroom_layout" />

        <include
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            layout="@layout/childrenbedroom_layout" />

        <include
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            layout="@layout/kitchen_layout" />

        <include
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            layout="@layout/dinningroom_layout" />

        <include
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            layout="@layout/corridor_layout" />

        <include
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            layout="@layout/roof_layout" />

        <include
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            layout="@layout/garden_layout" />

        <include
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            layout="@layout/garage_layout" />

        <include
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            layout="@layout/container_mainlayout" />
    </ViewFlipper>

    <include
        android:layout_width="300dp"
        android:layout_height="match_parent"
        android:layout_above="@+id/include_footerbar"
        android:layout_alignParentRight="true"
        android:layout_below="@+id/include_headerbar"
        layout="@layout/slidingdrawer_infolayout" />

    <include
        android:layout_width="300dp"
        android:layout_height="400dp"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        layout="@layout/slidingdrawer_roomslistlayout" />

    <include
        android:layout_width="350dp"
        android:layout_height="300dp"
        android:layout_above="@+id/include_footerbar"
        android:layout_alignParentRight="true"
        layout="@layout/logger_layout" />

    <include
        android:id="@+id/include_relativeMenu"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_below="@+id/include_headerbar"
        layout="@layout/options_menulayout" />

</RelativeLayout>

options_menuLayout xml代码:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/main_optionLayout"
android:layout_width="200dp"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:background="@drawable/main_headerbackground"
android:orientation="vertical"
android:visibility="invisible" >

<Button
    android:id="@+id/relativeMenuAllSensorsButton"
    android:layout_width="200dp"
    android:layout_height="50dp"
    android:layout_alignParentTop="true"
    android:background="@drawable/main_headerbackground"
    android:gravity="center_vertical|center_horizontal"
    android:text="Activation List"
    android:textColor="@android:color/white"
    android:textSize="18sp" />

<Button
    android:id="@+id/relativeMenuUsersButton"
    android:layout_width="200dp"
    android:layout_height="50dp"
    android:layout_below="@+id/relativeMenuAllSensorsButton"
    android:background="@drawable/main_headerbackground"
    android:gravity="center_vertical|center_horizontal"
    android:text="Users"
    android:textColor="@android:color/white"
    android:textSize="18sp" />

<Button
    android:id="@+id/relativeMenuPreferencesButton"
    android:layout_width="200dp"
    android:layout_height="50dp"
    android:layout_below="@+id/relativeMenuUsersButton"
    android:background="@drawable/main_headerbackground"
    android:gravity="center_vertical|center_horizontal"
    android:text="Settings"
    android:textColor="@android:color/white"
    android:textSize="18sp" />

我尝试清理项目,重建工作区甚至使用不同的模拟器,但同样的问题仍然存在!

Answer 1

在main3d_activity.xml你有:

<include
    android:id="@+id/include_relativeMenu"
    android:layout_width="200dp"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
     android:layout_below="@+id/include_headerbar"
    layout="@layout/options_menulayout" />

然后在options_menulayout.xml你有:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/main_optionLayout"

因此,当您包含id时,它看起来像是覆盖了id.去掉

    android:id="@+id/include_relativeMenu"

从包含,或搜索该ID而不是另一个.