1

根据标题,当我尝试调用getDrawablesList()setupUI()在我的ImageSectionFragment().

getDrawablesList()setupUI()在一个单独的项目中进行了测试,onCreate()它们工作得非常好。

我怀疑这与我在FragmentActivity.

任何帮助将不胜感激。

public class MainActivity extends FragmentActivity {
    SectionsPagerAdapter mSectionsPagerAdapter;
    ViewPager mViewPager;
    public String SERVERIP;
    private TCPClient mTcpClient;
    private ArrayList<String> arrayList;
    private ImageView selectedImageView;
    private ImageView leftArrowImageView;
    private ImageView rightArrowImageView;
    private Gallery gallery;
    private int selectedImagePosition = 0;
    private List<Drawable> drawables;
    private GalleryImageAdapter galImageAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_page);
        arrayList = new ArrayList<String>();
        Bundle extras = getIntent().getExtras();
        SERVERIP = extras.getString("key");
        // Create the adapter that will return a fragment for each of the three
        // primary sections of the app.
        mSectionsPagerAdapter = new SectionsPagerAdapter(
                getSupportFragmentManager());

        // Set up the ViewPager with the sections adapter.
        mViewPager = (ViewPager) findViewById(R.id.pager);
        mViewPager.setAdapter(mSectionsPagerAdapter);

        if (SERVERIP == "null") {
            Log.d("MainActivity.java", "Continue without connection selected");
        }

        else {
            new connectTask().execute("");
        }
    }

    /**
     * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
     * one of the sections/tabs/pages.
     */
    public class SectionsPagerAdapter extends FragmentPagerAdapter {

        public SectionsPagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int position) {
            // getItem is called to instantiate the fragment for the given page.
            // Return a DummySectionFragment (defined as a static inner class
            // below) with the page number as its lone argument.
            /*
             * Fragment fragment = new DummySectionFragment(); Bundle args = new
             * Bundle(); args.putInt(DummySectionFragment.ARG_SECTION_NUMBER,
             * position + 1); fragment.setArguments(args); return fragment;
             */
            Fragment fragment = new Fragment();
            if (position == 0) {
                fragment = new DummySectionFragment();
            }

            else if (position == 1) {
                fragment = new ImageSectionFragment();
            }

            return fragment;
        }

        @Override
        public int getCount() {
            // Show 3 total pages.
            return 3;
        }

        @Override
        public CharSequence getPageTitle(int position) {
            Locale l = Locale.getDefault();
            switch (position) {
            case 0:
                return getString(R.string.title_section1).toUpperCase(l);
            case 1:
                return getString(R.string.title_section2).toUpperCase(l);
            case 2:
                return getString(R.string.title_section3).toUpperCase(l);
            }
            return null;
        }
    }

    /**
     * A dummy fragment representing a section of the app, but that simply
     * displays dummy text.
     */
    public static class DummySectionFragment extends Fragment {
        /**
         * The fragment argument representing the section number for this
         * fragment.
         */
        public DummySectionFragment() {

        }

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

    public static class ImageSectionFragment extends Fragment {
        /**
         * The fragment argument representing the section number for this
         * fragment.
         */
        MainActivity ma = new MainActivity();
        public ImageSectionFragment() {

        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_imagepage,container, false);
            ma.getDrawablesList();
            ma.setupUI();
            return rootView;
        }


    }

    private void setupUI() {

        selectedImageView = (ImageView) findViewById(R.id.selected_imageview);
        leftArrowImageView = (ImageView) findViewById(R.id.left_arrow_imageview);
        rightArrowImageView = (ImageView) findViewById(R.id.right_arrow_imageview);
        gallery = (Gallery) findViewById(R.id.gallery);

        leftArrowImageView.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {

                if (selectedImagePosition > 0) {
                    --selectedImagePosition;

                }

                gallery.setSelection(selectedImagePosition, false);
            }
        });

        rightArrowImageView.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {

                if (selectedImagePosition < drawables.size() - 1) {
                    ++selectedImagePosition;

                }

                gallery.setSelection(selectedImagePosition, false);

            }
        });

        gallery.setOnItemSelectedListener(new OnItemSelectedListener() {

            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {

                selectedImagePosition = pos;

                if (selectedImagePosition > 0 && selectedImagePosition < drawables.size() - 1) {

                    leftArrowImageView.setImageDrawable(getResources().getDrawable(R.drawable.arrow_left_enabled));
                    rightArrowImageView.setImageDrawable(getResources().getDrawable(R.drawable.arrow_right_enabled));

                } else if (selectedImagePosition == 0) {

                    leftArrowImageView.setImageDrawable(getResources().getDrawable(R.drawable.arrow_left_disabled));

                } else if (selectedImagePosition == drawables.size() - 1) {

                    rightArrowImageView.setImageDrawable(getResources().getDrawable(R.drawable.arrow_right_disabled));
                }

                changeBorderForSelectedImage(selectedImagePosition);
                setSelectedImage(selectedImagePosition);
            }

            @Override
            public void onNothingSelected(AdapterView<?> arg0) {

            }

        });

        galImageAdapter = new GalleryImageAdapter(this, drawables);

        gallery.setAdapter(galImageAdapter);

        if (drawables.size() > 0) {

            gallery.setSelection(selectedImagePosition, false);

        }

        if (drawables.size() == 1) {

            rightArrowImageView.setImageDrawable(getResources().getDrawable(R.drawable.arrow_right_disabled));
        }

    }

    private void changeBorderForSelectedImage(int selectedItemPos) {

        int count = gallery.getChildCount();

        for (int i = 0; i < count; i++) {

            ImageView imageView = (ImageView) gallery.getChildAt(i);
            imageView.setBackgroundDrawable(getResources().getDrawable(R.drawable.image_border));
            imageView.setPadding(3, 3, 3, 3);

        }

        ImageView imageView = (ImageView) gallery.getSelectedView();
        imageView.setBackgroundDrawable(getResources().getDrawable(R.drawable.selected_image_border));
        imageView.setPadding(3, 3, 3, 3);
    }

    private void getDrawablesList() {

        drawables = new ArrayList<Drawable>();
        drawables.add(getResources().getDrawable(R.drawable.natureimage1));
        drawables.add(getResources().getDrawable(R.drawable.natureimage2));
        drawables.add(getResources().getDrawable(R.drawable.natureimage3));
        drawables.add(getResources().getDrawable(R.drawable.natureimage4));
        drawables.add(getResources().getDrawable(R.drawable.natureimage5));
        drawables.add(getResources().getDrawable(R.drawable.natureimage6));
        drawables.add(getResources().getDrawable(R.drawable.natureimage7));
        drawables.add(getResources().getDrawable(R.drawable.natureimage8));
        drawables.add(getResources().getDrawable(R.drawable.natureimage9));
        drawables.add(getResources().getDrawable(R.drawable.natureimage10));
        drawables.add(getResources().getDrawable(R.drawable.natureimage11));
        drawables.add(getResources().getDrawable(R.drawable.natureimage12));
        drawables.add(getResources().getDrawable(R.drawable.natureimage13));
        drawables.add(getResources().getDrawable(R.drawable.natureimage14));
        drawables.add(getResources().getDrawable(R.drawable.natureimage15));

    }

    private void setSelectedImage(int selectedImagePosition) {

        BitmapDrawable bd = (BitmapDrawable) drawables.get(selectedImagePosition);
        Bitmap b = Bitmap.createScaledBitmap(bd.getBitmap(), (int) (bd.getIntrinsicHeight() * 0.9), (int) (bd.getIntrinsicWidth() * 0.7), false);
        selectedImageView.setImageBitmap(b);
        selectedImageView.setScaleType(ScaleType.FIT_XY);

    }

    public class connectTask extends AsyncTask<String, String, TCPClient> {

        @Override
        protected TCPClient doInBackground(String... message) {

            // we create a TCPClient object and
            mTcpClient = new TCPClient(new TCPClient.OnMessageReceived() {
                @Override
                // here the messageReceived method is implemented
                public void messageReceived(String message) {
                    // this method calls the onProgressUpdate
                    publishProgress(message);
                }
            });
            mTcpClient.run(SERVERIP);

            return null;
        }

        @Override
        protected void onProgressUpdate(String... values) {
            super.onProgressUpdate(values);

            // in the arrayList we add the messaged received from server
            arrayList.add(values[0]);
            // notify the adapter that the data set has changed. This means that
            // new message received
            // from server was added to the list

        }
    }
}

这是日志猫

07-16 14:21:48.664: E/AndroidRuntime(26188): FATAL EXCEPTION: main
07-16 14:21:48.664: E/AndroidRuntime(26188): java.lang.NullPointerException
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.content.ContextWrapper.getResources(ContextWrapper.java:81)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at com.fypj.mdm.MainActivity.getDrawablesList(MainActivity.java:273)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at com.fypj.mdm.MainActivity.access$0(MainActivity.java:270)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at com.fypj.mdm.MainActivity$ImageSectionFragment.onCreateView(MainActivity.java:160)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.support.v4.app.Fragment.performCreateView(Fragment.java:1460)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:911)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1088)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1444)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:461)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.support.v4.view.ViewPager.populate(ViewPager.java:1064)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.support.v4.view.ViewPager.populate(ViewPager.java:911)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1432)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.view.View.measure(View.java:15481)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5107)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.view.View.measure(View.java:15481)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.widget.LinearLayout.measureVertical(LinearLayout.java:833)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.widget.LinearLayout.onMeasure(LinearLayout.java:574)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.view.View.measure(View.java:15481)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5107)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2361)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.view.View.measure(View.java:15481)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1999)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1238)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1413)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1131)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4611)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.view.Choreographer.doCallbacks(Choreographer.java:555)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.view.Choreographer.doFrame(Choreographer.java:525)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.os.Handler.handleCallback(Handler.java:615)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.os.Handler.dispatchMessage(Handler.java:92)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.os.Looper.loop(Looper.java:137)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at android.app.ActivityThread.main(ActivityThread.java:4898)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at java.lang.reflect.Method.invokeNative(Native Method)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at java.lang.reflect.Method.invoke(Method.java:511)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1008)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:775)
07-16 14:21:48.664: E/AndroidRuntime(26188):    at dalvik.system.NativeStart.main(Native Method)
4

1 回答 1

1

你不能像这样实例化一个活动

 MainActivity ma = new MainActivity();

您需要做的是覆盖片段中的 onAttach(Activity) 并将活动分配给 ma

    Activity ma;

    public void onAttach (Activity activity){
         ma = activity;
    }

或者使用getActivity()方法在需要的地方获取 Activity

于 2013-07-16T07:17:05.183 回答