ExpandableListView爲null

Question

我是新來的android和我一直在嘗試使用jfeinstein滑動菜單和可擴展列表。 我的問題是，我每次使用findViewById爲expandablelist

這裏時間越來越空是我的代碼

主要活動

protected void onCreate(Bundle savedInstanceState) { 
    try{ 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     this.app = (App) getApplication(); 
     app.menu = new SlidingMenu(app); 
     app.menu.setMode(SlidingMenu.LEFT); 
     app.menu.setTouchModeAbove(SlidingMenu.TOUCHMODE_FULLSCREEN); 
     app.menu.setFadeDegree(0.50f); 
     app.menu.attachToActivity(this, SlidingMenu.SLIDING_CONTENT); 
     app.menu.setShadowDrawable(R.drawable.shadow); 
     app.menu.setShadowWidthRes(R.dimen.shadow_width); 

     app.menu.setBehindOffsetRes(R.dimen.slidingmenu_offset); 
     app.menu.setEnabled(true); 

     app.adapter = new SlideMenuList(this, app, parent, child); 
     app.listView = (ExpandableListView) app.menu.findViewById(R.id.slide_list); 
     app.listView.setAdapter(app.adapter); 
     app.listView.setOnChildClickListener(app.adapter); 
     app.listView.setOnGroupExpandListener(app.adapter); 

     android.support.v7.app.ActionBar ac = getSupportActionBar(); 

     ac.setHomeButtonEnabled(true); 
     init(); 
    }catch(Exception e){ 
     e.printStackTrace(); 
    } 

activity_main.xml中

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:id="@+id/splash_screen" 
android:layout_width="fill_parent" 
android:layout_height="fill_parent" 
android:animateLayoutChanges="true" 
android:paddingBottom="@dimen/activity_vertical_margin" 
android:paddingLeft="@dimen/activity_horizontal_margin" 
android:paddingRight="@dimen/activity_horizontal_margin" 
android:paddingTop="@dimen/activity_vertical_margin" 
tools:context="com.jaggz.gurudawaraapp.MainActivity" > 


<FrameLayout 
    android:id="@+id/frame_container" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentBottom="true" 
    android:layout_alignParentLeft="true" 
    android:layout_alignParentRight="true" 
    android:layout_alignParentTop="true" > 

    </FrameLayout> 

</RelativeLayout> 

expandable_li st.xml

<?xml version="1.0" encoding="utf-8"?> 
<ExpandableListView xmlns:android="http://schemas.android.com/apk/res/android" 
android:id="@+id/slide_list" 
android:layout_width="match_parent" 
android:layout_height="match_parent" > 
</ExpandableListView> 

錯誤

11-23 15:24:28.187: W/System.err(13349): java.lang.NullPointerException 
11-23 15:24:28.187: W/System.err(13349): at com.jaggz.gurudwaraapp.MainActivity.onCreate(MainActivity.java:64) 
11-23 15:24:28.187: W/System.err(13349): at android.app.Activity.performCreate(Activity.java:5312) 
11-23 15:24:28.187: W/System.err(13349): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1111) 
11-23 15:24:28.187: W/System.err(13349): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2552) 
11-23 15:24:28.187: W/System.err(13349): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2653) 
11-23 15:24:28.187: W/System.err(13349): at android.app.ActivityThread.access$800(ActivityThread.java:156) 
11-23 15:24:28.187: W/System.err(13349): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1355) 
11-23 15:24:28.187: W/System.err(13349): at android.os.Handler.dispatchMessage(Handler.java:102) 
11-23 15:24:28.187: W/System.err(13349): at android.os.Looper.loop(Looper.java:157) 
11-23 15:24:28.187: W/System.err(13349): at android.app.ActivityThread.main(ActivityThread.java:5872) 
11-23 15:24:28.187: W/System.err(13349): at java.lang.reflect.Method.invokeNative(Native Method) 
11-23 15:24:28.187: W/System.err(13349): at java.lang.reflect.Method.invoke(Method.java:515) 
11-23 15:24:28.187: W/System.err(13349): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858) 
11-23 15:24:28.187: W/System.err(13349): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:674) 
11-23 15:24:28.187: W/System.err(13349): at dalvik.system.NativeStart.main(Native Method) 

請大家幫幫忙

Answer 1

試圖將expandable_list.xml的代碼進入你的activity_main.xml中

Answer 2

試試這個：

app.menu.setBehindOffsetRes(R.dimen.slidingmenu_offset); 
    app.menu.setEnabled(true); 

    app.adapter = new SlideMenuList(this, app, parent, child); 
    **app.listView = (ExpandableListView) app.menu.findViewById(R.id.slidingmenu_view);** 
    app.listView.setAdapter(app.adapter); 
    app.listView.setOnChildClickListener(app.adapter); 
    app.listView.setOnGroupExpandListener(app.adapter);