android - ClassCastException android.widget.FrameLayout$LayoutParams 到 android.support.v4.widget.DrawerLayout$LayoutParams

Question

我正在开发适用于 Android 的抽屉导航。根据我的要求，我是在抽屉导航中显示项目的 GridView 和 ListView 。我在布局 xml 文件中创建了一个线性布局，并将两个小部件( GridView 和 ListView )放置在线性布局中。

当我运行该文件时，我收到以下错误:

java.lang.RuntimeException: 无法启动 Activity ComponentInfo{com.example.navigationdrawer3/com.example.navigationdrawer3.MainActivity}: java.lang.ClassCastException: android.widget.FrameLayout$LayoutParams 无法转换为android.support.v4.widget.DrawerLayout$LayoutParams

以下是我的 java、logcat 和 NavigationDrawer 布局文件:

MainActivity.java

public class MainActivity extends Activity {

     private DrawerLayout mDrawerLayout;
        private ListView mDrawerList;
        private ActionBarDrawerToggle mDrawerToggle;

        private CharSequence mDrawerTitle;
        //@SuppressWarnings("unused")
        private CharSequence mTitle;
        private String[] mGalaxyTitles;

        private GridView mDrawerGrid;

        private LinearLayout mDrawerLinear;

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

        mTitle = mDrawerTitle = getTitle();
        mGalaxyTitles = getResources().getStringArray(R.array.items_array);
        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mDrawerList = (ListView) findViewById(R.id.left_drawer);

        mDrawerGrid = (GridView)findViewById(R.id.gridview);

        mDrawerLinear =(LinearLayout)findViewById(R.id.linearLayout);

        mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);

        mDrawerGrid.setAdapter(new ImageAdapter(MainActivity.this));

        mDrawerList.setAdapter(new ArrayAdapter<String>(this,
                R.layout.drawer_list_item, mGalaxyTitles));

        mDrawerList.setOnItemClickListener(new DrawerItemClickListener());

        getActionBar().setDisplayHomeAsUpEnabled(true);
        getActionBar().setHomeButtonEnabled(true);      

        mDrawerToggle = new ActionBarDrawerToggle(
                this,                  
                mDrawerLayout,         
                R.drawable.ic_drawer,  
                R.string.drawer_open,  
                R.string.drawer_close  
                ) {
            public void onDrawerClosed(View view) {
                getActionBar().setTitle(mDrawerTitle);
                invalidateOptionsMenu(); 
            }

            public void onDrawerOpened(View drawerView) {
                getActionBar().setTitle(mDrawerTitle);
                invalidateOptionsMenu(); 
            }
        };
        mDrawerLayout.setDrawerListener(mDrawerToggle);

        if (savedInstanceState == null) {
            selectItem(0);
        }

    }

    class DrawerItemClickListener implements ListView.OnItemClickListener {

        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position,
                long id) {
            // TODO Auto-generated method stub

switch(position){

            case 0:
               menu0(); 
                return;
            case 1:
               menu1(); 
                return;
            case 2:
                menu2(); 
                 return;
            case 3:
               menu3(); 
                return;
            case 4:
               menu4(); 
                return;
            case 5:
               menu5(); 
                return;
            case 6:
               menu6(); 
                return;
            case 7:
               menu7(); 
                return;
            case 8:
               menu8(); 
                return;
        }

        }


        protected void menu0() {
            Intent Main0 = new Intent(MainActivity.this, Page0.class);
            startActivity(Main0);
               return;
        }

        protected void menu1() {
            Intent Main1 = new Intent(MainActivity.this, Page1.class);
            startActivity(Main1);
               return;
        }

        protected void menu2() {
              Intent Main2 = new Intent(MainActivity.this, Page2.class);
              startActivity(Main2);
           return;
    }
        protected void menu3() {
            Intent Main3 = new Intent(MainActivity.this, Page3.class);
            startActivity(Main3);
               return;
        }

        protected void menu4() {
            Intent Main4 = new Intent(MainActivity.this, Page4.class);
            startActivity(Main4);
               return;
        }

        protected void menu5() {
            Intent Main5 = new Intent(MainActivity.this, Page5.class);
            startActivity(Main5);
               return;
        }

        protected void menu6() {
            Intent Main6 = new Intent(MainActivity.this, Page6.class);
            startActivity(Main6);
               return;
        }

        protected void menu7() {
            Intent Main7 = new Intent(MainActivity.this, Page7.class);
            startActivity(Main7);
               return;
        }

        protected void menu8() {
            Intent Main8 = new Intent(MainActivity.this, Page8.class);
            startActivity(Main8);
               return;
        }

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }


     @Override
        public void setTitle(CharSequence title) {
            mTitle = title;
            getActionBar().setTitle(mDrawerTitle);
        }

       @Override
        public boolean onPrepareOptionsMenu(Menu menu) {
           //boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
           //boolean drawerOpen2 = mDrawerLayout.isDrawerOpen(mDrawerGrid);
           boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerLayout);
            menu.findItem(R.id.action_settings).setVisible(!drawerOpen);
            //menu.findItem(R.id.action_settings).setVisible(!drawerOpen2);
            return super.onPrepareOptionsMenu(menu);
        }

       @Override
        public boolean onOptionsItemSelected(MenuItem item) {
            if (mDrawerToggle.onOptionsItemSelected(item)) {
                return true;
            }

            switch(item.getItemId()) {
            case R.id.action_settings:
                setting();

                return true;

            case R.id.about:
                about();

                return true;
            default:
                return super.onOptionsItemSelected(item);
            }
        }

     private void about() {
        // TODO Auto-generated method stub

         Intent Main1 = new Intent(MainActivity.this, About.class);
            startActivity(Main1);
               return;

    }


    private void setting() {
        // TODO Auto-generated method stub
        Intent Main1 = new Intent(MainActivity.this, Setting.class);
        startActivity(Main1);
           return;

    }


    private void selectItem(int position) {


            Fragment fragment = new GalaxyFragment();
            Bundle args = new Bundle();
            args.putInt(GalaxyFragment.ARG_GALAXY_NUMBER, position);
            fragment.setArguments(args);

            FragmentManager fragmentManager = getFragmentManager();
            fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();


            mDrawerList.setItemChecked(position, true);
            setTitle(mGalaxyTitles[position]);
            mDrawerLayout.closeDrawer(mDrawerLayout);
            //mDrawerLayout.closeDrawer(mDrawerGrid);
        }

     class GalaxyFragment extends Fragment{

        public static final String ARG_GALAXY_NUMBER = "galaxy_number";

         public GalaxyFragment() {

            }

            @Override
            public View onCreateView(LayoutInflater inflater, ViewGroup container,
                    Bundle savedInstanceState) {
                View rootView = inflater.inflate(R.layout.about, container, false);           

                return rootView;
            }

     }


     //Gridview BaseAdapter class

     class ImageAdapter extends BaseAdapter{
            Context context;

        ImageAdapter(Context context){
                this.context = context;
            }


            @Override
            public int getCount() {
                // TODO Auto-generated method stub
                return mThumbIds.length;
            }

            @Override
            public Object getItem(int arg0) {
                // TODO Auto-generated method stub
                return null;
            }

            @Override
            public long getItemId(int arg0) {
                // TODO Auto-generated method stub
                return 0;
            }

            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                // TODO Auto-generated method stub
                ImageView imageView;

                if(convertView == null){
                    imageView = new ImageView(context);
                     imageView.setLayoutParams(new GridView.LayoutParams(25, 25));
                     imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
                     imageView.setPadding(8, 8, 8, 8);
                }else {
                    imageView = (ImageView) convertView;
                }
                imageView.setImageResource(mThumbIds[position]);
                return imageView;
            }

             // references to our images
            private Integer[] mThumbIds = {
                    R.drawable.sample_2, R.drawable.sample_3,
                    R.drawable.sample_4, R.drawable.sample_5,
            };

        }

}

activity_main.xml

<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" 
    android:id="@+id/drawer_layout">

     <FrameLayout
        android:id="@+id/content_frame"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >
    </FrameLayout>

      <LinearLayout
         android:id="@+id/linearLayout"
         android:layout_width="320dp"
         android:layout_height="match_parent"
         android:orientation="vertical" 
         android:layout_gravity="left"
        android:choiceMode="singleChoice"
        android:divider="@android:color/transparent"
        android:dividerHeight="0dp"
        android:background="#111">        


    <GridView 
        android:id="@+id/gridview"
        android:layout_width="280dp"
        android:layout_height="match_parent"
        android:stretchMode="columnWidth"
        android:numColumns="auto_fit"/>
       <!--  android:gravity="center"   --> 
    <ListView
        android:id="@+id/left_drawer"
        android:layout_width="240dp"
        android:layout_height="match_parent"
        />

   </LinearLayout>     

</android.support.v4.widget.DrawerLayout>

logcat

07-30 06:15:57.203: W/dalvikvm(853): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
07-30 06:15:57.213: E/AndroidRuntime(853): FATAL EXCEPTION: main
07-30 06:15:57.213: E/AndroidRuntime(853): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.navigationdrawer3/com.example.navigationdrawer3.MainActivity}: java.lang.ClassCastException: android.widget.FrameLayout$LayoutParams cannot be cast to android.support.v4.widget.DrawerLayout$LayoutParams
07-30 06:15:57.213: E/AndroidRuntime(853):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
07-30 06:15:57.213: E/AndroidRuntime(853):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
07-30 06:15:57.213: E/AndroidRuntime(853):  at android.app.ActivityThread.access$600(ActivityThread.java:141)
07-30 06:15:57.213: E/AndroidRuntime(853):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
07-30 06:15:57.213: E/AndroidRuntime(853):  at android.os.Handler.dispatchMessage(Handler.java:99)
07-30 06:15:57.213: E/AndroidRuntime(853):  at android.os.Looper.loop(Looper.java:137)
07-30 06:15:57.213: E/AndroidRuntime(853):  at android.app.ActivityThread.main(ActivityThread.java:5041)
07-30 06:15:57.213: E/AndroidRuntime(853):  at java.lang.reflect.Method.invokeNative(Native Method)
07-30 06:15:57.213: E/AndroidRuntime(853):  at java.lang.reflect.Method.invoke(Method.java:511)
07-30 06:15:57.213: E/AndroidRuntime(853):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
07-30 06:15:57.213: E/AndroidRuntime(853):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
07-30 06:15:57.213: E/AndroidRuntime(853):  at dalvik.system.NativeStart.main(Native Method)
07-30 06:15:57.213: E/AndroidRuntime(853): Caused by: java.lang.ClassCastException: android.widget.FrameLayout$LayoutParams cannot be cast to android.support.v4.widget.DrawerLayout$LayoutParams
07-30 06:15:57.213: E/AndroidRuntime(853):  at android.support.v4.widget.DrawerLayout.isDrawerView(DrawerLayout.java:809)
07-30 06:15:57.213: E/AndroidRuntime(853):  at android.support.v4.widget.DrawerLayout.closeDrawer(DrawerLayout.java:1012)
07-30 06:15:57.213: E/AndroidRuntime(853):  at com.example.navigationdrawer3.MainActivity.selectItem(MainActivity.java:265)
07-30 06:15:57.213: E/AndroidRuntime(853):  at com.example.navigationdrawer3.MainActivity.onCreate(MainActivity.java:86)
07-30 06:15:57.213: E/AndroidRuntime(853):  at android.app.Activity.performCreate(Activity.java:5104)
07-30 06:15:57.213: E/AndroidRuntime(853):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
07-30 06:15:57.213: E/AndroidRuntime(853):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
07-30 06:15:57.213: E/AndroidRuntime(853):  ... 11 more

第 86 行代码行:

selectItem(0);

第 265 行的代码行:

mDrawerLayout.closeDrawer(mDrawerLayout);

我已尝试以多种方式更正此运行时错误，但未能更正。任何人都可以为我的问题提出一个答案。

Answer 1

是什么为我解决了这个问题:

在MainActivity中，为LinearLayout添加一个新的字段，并在onCreate()中给它赋值(这部分就像emaleavil suggested ):

private LinearLayout linearLayout;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // ...
    linearLayout = (LinearLayout) findViewById(R.id.linearLayout);
}

然后在selectItem()中，调用closeDrawer()时，只需传入linearLayout作为参数即可:

drawerLayout.closeDrawer(linearLayout);