Question

我用Viewpager创建了一个tablayout.Tablayout有三个3片段'Photo'，'Video'，'Docs'。每个片段都有一个gridview。在“照片”片段中，图像作为缩略图加载到gridview，“视频”片段视频以缩略图的形式加载到gridview，依此类推。当图像加载到“照片”片段中的Gridview时，之后当应用程序被杀死并再次打开时，Gridview已经失去了它没有上传图像的状态。我知道这种情况正在发生，因为onCreateView正在再次创建整个UI。但是如何在它被杀之前保存碎片的状态？这是代码..

//加载viewpager的MainFragment

    public class MainFragment extends Fragment {
static FragmentManager fManager;
static ViewPager viewPager;
View view;
static ViewPagerAdapter adapter;

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

    view = inflater.inflate(R.layout.activity_main, container, false);
    viewPager = (ViewPager) view.findViewById(R.id.viewpager);
    viewPager.setOffscreenPageLimit(1);
    fManager = getChildFragmentManager();
    adapter = new ViewPagerAdapter(fManager);
    viewPager.setAdapter(adapter);
    return view;
}

public static MainFragment newInstance() {
    MainFragment fragment = new MainFragment();
    Bundle args = new Bundle();
    fragment.setArguments(args);
    return fragment;
}
    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
    List<Fragment> listOfFragments = getChildFragmentManager().getFragments();

    if (listOfFragments.size() >= 1) {
        for (Fragment fragment : listOfFragments) {
            if (fragment instanceof PhotoFragment) {
                fragment.onActivityResult(requestCode, resultCode, data);
            }
           else if (fragment instanceof VideoFragment) {
                fragment.onActivityResult(requestCode, resultCode, data);
            }

        }
    }
    super.onActivityResult(requestCode, resultCode, data);
}
    }

// Photo Fragment

    public class PhotoFragment extends Fragment {

private GridView gridView;
private View view;
private Dialog dialog = null;
private ImageView btnCamera;
TextView btnCameradialog, btnGalleryDialog;
private final int CLICK_PHOTO = 1;
private final int SELECT_PHOTO = 2;
private Uri imageUri;
private String path, picturePath, pathlist;
private List<PictureBeans> pictureDisplayList = null;
private ImageAdapter adapter;
private TextView textViewtitle;
private boolean isVisibleToUser = false;


public PhotoFragment() {
    // Required empty public constructor
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    if(isVisibleToUser == false) {
        view = inflater.inflate(R.layout.fragment_photo, container, false);

        initUI();
        setListener();


    }
        return view;
}

private void initUI() {

    btnCamera = (ImageView) view.findViewById(R.id.fabPicture);

    gridView = (GridView) view.findViewById(R.id.grid_view_photoFragment);

    pictureDisplayList = new ArrayList<>();
}


private void setListener() {
    btnCamera.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            showappwindow();
        }
    });

    gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Intent i = new Intent(getActivity(), FullImageActivity.class);
            i.putExtra("id", position);
            i.putExtra("path", pictureDisplayList.get(position).getPicturePath().toString());
            startActivity(i);
        }
    });
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) {
    super.onActivityResult(requestCode, resultCode, imageReturnedIntent);
    switch (requestCode) {
        case SELECT_PHOTO:
            if (resultCode == Activity.RESULT_OK) {
                try {
                    imageUri = imageReturnedIntent.getData();
                    path = Util.getRealPathFromURI(getActivity(), imageUri);
                    Log.v("Uri", "" + imageUri);
                    picturePath = path.toString();
                    Log.e("Picture Path in Frag ", "" + picturePath);
                    PictureBeans bean = new PictureBeans();
                    bean.setPicturePath(picturePath);
                    pictureDisplayList.add(bean);
                    Log.e("List size", "" + pictureDisplayList.size());

                    addToAdapter(pictureDisplayList);

                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
            break;

        case CLICK_PHOTO:
            if (resultCode == Activity.RESULT_OK) {

                try {
                    imageUri = imageReturnedIntent.getData();
                    path = Util.getRealPathFromURI(getActivity(), imageUri);
                    Log.e("PATH",""+path);
                    picturePath = path.toString();
                    PictureBeans bean = new PictureBeans();
                    bean.setPicturePath(picturePath);
                    pictureDisplayList.add(bean);

                    addToAdapter(pictureDisplayList);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
            break;
    }
}

private void addToAdapter(List<PictureBeans> pictureDisplayList) {

    adapter = new ImageAdapter(getActivity(), pictureDisplayList);
    gridView.setAdapter(adapter);
}

// Pop Up window Code
public void showappwindow() {
    dialog = new Dialog(getActivity(), R.style.mydialogstyle);
    dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
    dialog.setContentView(R.layout.dialog_photo);

    textViewtitle = (TextView) dialog.findViewById(R.id.tvTitle);
    textViewtitle.setText("Upload Image");

    btnCameradialog = (TextView) dialog.findViewById(R.id.btnCameradialog);
    btnGalleryDialog = (TextView) dialog.findViewById(R.id.btnGalleryDialog);
    dialog.show();

    btnCameradialog.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
            getParentFragment().startActivityForResult(cameraIntent, CLICK_PHOTO);
            dialog.dismiss();
        }
    });

    btnGalleryDialog.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent photoPickerIntent = new Intent(Intent.ACTION_PICK);
            photoPickerIntent.setType("image/*");
            getParentFragment().startActivityForResult(photoPickerIntent, SELECT_PHOTO);
            dialog.dismiss();
        }
    });
}
    }

//适配器

    public class ViewPagerAdapter extends FragmentStatePagerAdapter {
final int PAGE_COUNT = 3;
private PhotoFragment photoFragment;
private VideoFragment videoFragment;
private ThreeFragment threeFragment;
private String[] titles = new String[]{"Photo", "Video", "Documents"};

public ViewPagerAdapter(FragmentManager manager) {
    super(manager);
}

@Override
public Fragment getItem(int position) {
    Bundle bundle = new Bundle();
    bundle.putInt("request.code", position + 1);
    switch (position) {

        case 0:
            photoFragment = new PhotoFragment();
            return photoFragment;

        case 1:
            videoFragment = new VideoFragment();
            return videoFragment;

        case 2:
            threeFragment = new ThreeFragment();
            return threeFragment;
    }
    return null;
}

@Override
public int getCount() {
    return PAGE_COUNT;
}

@Override
public CharSequence getPageTitle(int position) {
    return titles[position];
}
    }

Answer 1

你可以在onDestroyView（）方法中保存片段状态，与Fragment一起使用参数

应用程序被杀死后如何在Viewpager中保存片段的状态

1 个答案: