Question

我正在尝试在Android Studio中创建导航菜单。但是我总是在listview声明中得到NullPointerException，或者类似于this。

这是我的代码。

主要活动

public class Java_Main扩展了ActionBarActivity {

ActionBarDrawerToggle toggle;
DrawerLayout drawerLayoutCekmece;
ListView liste;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

   Toolbar toolbar = (Toolbar) findViewById(R.id.toolbarMain);
    toolbar.setBackgroundColor(Color.GREEN);
    setSupportActionBar(toolbar);

    drawerLayoutCekmece  = (DrawerLayout) findViewById(R.id.drawer12);


    liste = (ListView) drawerLayoutCekmece.findViewById(R.id.listeDrawer);
    liste.setAdapter(new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,getResources().getStringArray(R.array.gunler)));

    liste.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            drawerLayoutCekmece.closeDrawer(liste);
        }
    });

    toggle = new ActionBarDrawerToggle(this,drawerLayoutCekmece , toolbar , R.string.string_pazartesi , R.string.string_sali)
    {
        @Override
        public void onDrawerClosed(View drawerView) {
            super.onDrawerClosed(drawerView);
            invalidateOptionsMenu();
            syncState();
        }

        @Override
        public void onDrawerOpened(View drawerView) {
            super.onDrawerOpened(drawerView);
            invalidateOptionsMenu();
            syncState();
        }
    };

    drawerLayoutCekmece.setDrawerListener(toggle);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setHomeButtonEnabled(true);}

activity_main.xml中

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
 <RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <include layout="@layout/my_toolbar"
    android:id="@+id/toolbarMain"
    />
     <include
         layout="@layout/layout_drawer"
         android:id="@+id/drawer12"/>
    <RelativeLayout
         android:layout_width="match_parent"
        android:layout_height="match_parent">
         <TextView
        android:id="@+id/textViewProgram"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/spinnerGunler"
        android:layout_marginBottom="20dp"
        android:layout_marginTop="15dp"
        android:lineSpacingExtra="2dp"
        android:textSize="20dp" />
    <Spinner
        android:id="@+id/spinnerGunler"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:entries="@array/gunler"
        android:layout_alignParentLeft="true" />
 </RelativeLayout>

和layout_drawer.xml

<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="400px" android:id="@+id/drawer" android:layout_height="800px">
    <FrameLayout android:layout_width="match_parent"
        android:layout_height="match_parent">
 <ListView
        android:layout_width="wrap_content" android:layout_height="wrap_content"
        android:entries="@array/gunler"
        android:id="@+id/listeDrawer"/>
</FrameLayout>
</android.support.v4.widget.DrawerLayout>

感谢您的帮助。抱歉英语不好。

创建导航抽屉时出现Android异常

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