Question

我使用片段来实现viewpager，viewpager也是一个片段，我正在实现一个后退按钮并点击它，片段返回到前一个片段，按下后退按钮，前一个片段再次加载并获取再次回应。我怎么能防止这种情况。我在下面添加了我的代码。

照片碎片： -

public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) 
    {           

    View view = inflater.inflate(R.layout.layout_photo, container, false);
    ButterKnife.inject(this, view);
    sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);
    editor = sharedPref.edit();
    if (sharedPref.contains("isViewPagerStarted")) {
    isViewPagerStarted = sharedPref.getBoolean("isViewPagerStarted",false);
    }

    Log.e("pagerstart", "" + isViewPagerStarted);
    if (isViewPagerStarted) {
        backButton.setVisibility(View.VISIBLE);
        Animation RightSwipe = AnimationUtils.loadAnimation(getActivity(),
                R.anim.slide_out_left);
        backButton.startAnimation(RightSwipe);

        backButton.setVisibility(View.INVISIBLE);
    } else {
        backButton.setVisibility(View.INVISIBLE);
    }

    editor.clear();
    editor.commit();

    // sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);
    //

    options = new DisplayImageOptions.Builder()
            .showImageForEmptyUri(R.drawable.plc_gallery).cacheOnDisk(true)
            .build();

    return view;
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onActivityCreated(savedInstanceState);

    mContext = getActivity();
    FontHelper.setFontFace(galleryHeader, FontType.FONT5);

    getGalleryInfo();
    onClickGridView();

}

private void onClickGridView() {
    gridView.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View v,
                int position, long id) {

            // String backStateName = fragment.getClass().getName();

            callViewPagerStarted();

            ViewPagerFragment viewPagerFragment = new ViewPagerFragment();
            Bundle bun = new Bundle();
            bun.putInt("position", position);
            bun.putStringArray("fullImage", imageUrls);
            // bun.putStringArray("desc", description);
            viewPagerFragment.setArguments(bun);
            transaction = getActivity().getSupportFragmentManager()
                    .beginTransaction();
            transaction.addToBackStack(null);
            transaction.replace(R.id.frameLayoutFragment,
                    viewPagerFragment, "viewFrag");

            transaction.commit();

            /*
             * // Send intent to SingleViewActivity Intent intent = new
             * Intent(getActivity(),ViewPagerActivity.class); // Pass image
             * index Bundle bundle=new Bundle();
             * bundle.putInt("position",position);
             * bundle.putStringArray("imageArray",imageUrls);
             * bundle.putStringArray("description",description);
             * intent.putExtras(bundle); startActivity(intent);
             */
        }

    });

}

public void callViewPagerStarted() {

    editor.putBoolean("isViewPagerStarted", true);
    editor.commit();

}

@Override
public void onResume() {
    // TODO Auto-generated method stub
    super.onResume();
    /* getGalleryInfo(); */
}

private void getGalleryInfo() {
    GetMesaGallery getTempleInfo = new GetMesaGallery();
    // getTempleInfo.setAppID("8eb24199-6838-43ac-b9ca-40031ab37e65");
    ProgresBar.start(mContext);

    ServiceManager.instance().enqueue(getTempleInfo, new ServiceListener() {

        @Override
        public void onComplete(Response arg0) {

            ProgresBar.stop();
            GetMesaGallerysResponse response = (GetMesaGallerysResponse) arg0;
            if (response.isValid()) {
                response.getImageDto();
                final ArrayList<ImageDto> galleryImageList = response
                        .getImageDto();
                thumbnailUrls = new String[galleryImageList.size()];
                // description = new String[galleryImageList.size()];
                imageUrls = new String[galleryImageList.size()];
                for (int i = 0; i < galleryImageList.size(); i++) {
                    try {
                        thumbnailUrls[i] = galleryImageList.get(i)
                                .getthumbnailURL();

                        /*
                         * description[i] = galleryImageList.get(i)
                         * .getdescription();
                         */
                        imageUrls[i] = galleryImageList.get(i).getimageURL();
                        loadGridView();
                    } catch (Exception e) {

                        e.printStackTrace();
                    }
                }

            } else {

            }

        }
    });

}

private void loadGridView() {

    try {

        GridViewAdapter adapter = new GridViewAdapter(getActivity(),
                thumbnailUrls);

        // Set the adapter to the gridview
        gridView.setAdapter(adapter);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

@Override
public void onSaveInstanceState(Bundle outState) {
    // Add variable to outState here
    super.onSaveInstanceState(outState);
}

ViewPager片段：

public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.layout_viewpager, container,
                false);
        ButterKnife.inject(this, view);

    backButton.setVisibility(View.VISIBLE);

    Animation RightSwipe = AnimationUtils.loadAnimation(getActivity(),
            R.anim.slide_in_right);
    backButton.startAnimation(RightSwipe);

    Log.e("insdie", "viewpager");

    return view;
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onActivityCreated(savedInstanceState);

    Bundle arguments = getArguments();
    position = arguments.getInt("position");
    Log.e("position", "" + position);
    fullImageUris = arguments.getStringArray("fullImage");
    txtDesc = arguments.getStringArray("desc");

    FontHelper.setFontFace(description, FontType.FONT6);
    description.setPaintFlags(description.getPaintFlags()
            | Paint.UNDERLINE_TEXT_FLAG);

    /*
     * List<Fragment> imageFragments = getFragments();
     */
    pageAdapter = new MyPagerAdapter(getActivity()
            .getSupportFragmentManager(), fullImageUris);

    mPager.setAdapter(pageAdapter);

    mIndicator.setViewPager_Text(mPager,description,txtDesc);
    mPager.setCurrentItem(position);
}

/*
 * @Override public void onResume() { // TODO Auto-generated method stub
 * super.onResume(); pageAdapter = new MyPagerAdapter(getActivity()
 * .getSupportFragmentManager(),fullImageUri);
 * mPager.setCurrentItem(position); mPager.setAdapter(pageAdapter);
 * mIndicator.setViewPager_Text(mPager, description, txtDesc); }
 */
@OnClick(R.id.left_arrow)
public void tapLeftArrow() {
    mPager.setCurrentItem(getItem(-1), true);
}

private int getItem(int i) {
    return mPager.getCurrentItem() + i;
}

@OnClick(R.id.right_arrow)
public void tapRightArrow() {
    mPager.setCurrentItem(getItem(+1), true);

}

@OnClick(R.id.imgBackBtn)
public void moveToPreviousFragment() {

    FragmentManager fm = getFragmentManager();
    if (fm.getBackStackEntryCount() > 0) {
        Log.i("MainActivity", "popping backstack");
        fm.popBackStack();

    } else {
        Log.i("MainActivity", "nothing on backstack, calling super");

    }
    // getActivity().onBackPressed();

}

Answer 1

我只是检查了我的片段的实例并解决了问题

public static PhotoFragment instance() {
        if (photoFragment == null) {
            photoFragment = new PhotoFragment();
        }
        return photoFragment;
    }

碎片再次被创建

1 个答案: