是否可以将一个对象从一个片段发送到另一个片段？

Question

我想从一个片段发送到另一个片段的对象是“post”。 DemandFragment 由一个列表视图组成，该列表视图由作为帖子对象的项目组成。

我需要将列表视图中的选定项目（在本例中为 postArrayList.get(position)）发送到 SelectedPostFragment。

我尝试过使用 bundle 但这不起作用...

有人知道如何解决这个问题吗？

需求片段：

public class DemandFragment extends Fragment {

ListView lv;
ArrayAdapter adapter;
ArrayList<Post> postArrayList;
private EditText editSearch;

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

    if(rootView != null){
        lv = (ListView) rootView.findViewById(R.id.listDemand);

        editSearch = (EditText) rootView.findViewById(R.id.search_post);

        lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                // clicked on item show post
                Post selectedPost = postArrayList.get(position);
                Bundle bundle = new Bundle();
                bundle.putParcelable("data", (Parcelable) selectedPost);
                FragmentManager fm = getActivity().getFragmentManager();
                Fragment fragment = new rang.afterflight.fragments.SelectedPostFragment();
                fragment.setArguments(bundle);
                fm.beginTransaction().replace(R.id.content_main, fragment).commit();
            }
        });
    }
    searchPost();
    return rootView;
}

public void searchPost(){
    editSearch.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            adapter.getFilter().filter(s);
        }

        @Override
        public void afterTextChanged(Editable s) {

        }
    });
}


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setHasOptionsMenu(true);

    ParseQuery<ParseObject> query = ParseQuery.getQuery("Post");

    postArrayList = new ArrayList<Post>();

    query.findInBackground(new FindCallback<ParseObject>() {
        public void done(List<ParseObject> postList, ParseException e) {
            if (e == null) {
                for (ParseObject object : postList) {
                    Post newPost = new Post();

                    newPost.setAirportParse((String) object.get("airport"));
                    newPost.setDateParse((String) object.get("date"));
                    newPost.setTimeParse((String) object.get("time"));
                    newPost.setPersonsParse((String) object.get("persons"));
                    newPost.setAddressParse((String) object.get("address"));
                    newPost.setFlightnrParse((String) object.get("address"));
                    newPost.setUsername((String) object.get("username"));
                    newPost.setImageFile((ParseFile) object.get("profilepic"));

                    postArrayList.add(newPost);
                }
                adapter = new ListViewAdapter(getActivity(), R.layout.item_cardview, postArrayList);
                lv.setAdapter(adapter);
            }
        }
    });
}

}

SelectedPostFragment：

public class SelectedPostFragment extends Fragment {
TextView airportPost, datePost, timePost, personsPost, addressPost,
        flightnrPost, postedbyPost, contactPost;


ImageView iv;

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

    airportPost = (TextView) rootView.findViewById(R.id.airport_post);
    datePost = (TextView) rootView.findViewById(R.id.date_post);
    timePost = (TextView) rootView.findViewById(R.id.time_post);
    personsPost = (TextView) rootView.findViewById(R.id.persons_post);
    addressPost = (TextView) rootView.findViewById(R.id.address_post);
    flightnrPost = (TextView) rootView.findViewById(R.id.flightnr_post);
    postedbyPost = (TextView) rootView.findViewById(R.id.postedby_post);
    contactPost = (TextView) rootView.findViewById(R.id.contact_post);

    Post selectedPost = getArguments().getParcelable("object");
    String s = (String) selectedPost.get("airport");
    Log.d("AIRPORT NAME", s);

    return rootView;
}

}

帖子：

@ParseClassName("Post")
public class Post extends ParseObject implements Serializable {

    public Post(){
        super();
    }

    public String getId(){
        return getString("objectId");
    }

    public void setId(String id){
        put("objectId", id);
    }

    //////////

    public String getUsername(){
        return getString("username");
    }

    public void setUsername(String username){
        put("username", username);
    }



    public String getAirportParse(){
        return getString("airport");
    }

    public void setAirportParse(String airport){
        put("airport", airport);
    }

    //////////


    public String getDateParse(){
        return getString("date");
    }

    public void setDateParse(String date){
        put("date", date);
    }


    //////////


    public String getTimeParse(){
        return getString("time");
    }

    public void setTimeParse(String time){
        put("time", time);
    }


    //////////


    public String getPersonsParse(){
        return getString("persons");
    }

    public void setPersonsParse(String persons){
        put("persons", persons);
    }


    //////////


    public String getAddressParse(){
        return getString("address");
    }

    public void setAddressParse(String address){
        put("address", address);
    }

    public String getFlightnrParse(){
        return getString("flightnr");
    }

    public void setFlightnrParse(String flightnr){
        put("flightnr", flightnr);
    }


    public Bitmap getImageFile(){
        Bitmap bmp = null;
        ParseFile image = getParseFile("profilepic");
        if(image != null){
            try {
                byte[] data = image.getData();
                bmp = BitmapFactory.decodeByteArray(data, 0, data.length);
            } catch (ParseException e) {
                e.printStackTrace();
                }
        }
        return bmp;
    }

    public void setImageFile(ParseFile file) {
        if (file != null) {
            put("profilepic", file);
        }
    }
}

Answer 1

我相信您的 Post 类也需要实现 Parcelable 以及在带有 putParcelable() 的片段之间的捆绑中传递它。

查看：Parcelable。

这也是一个很棒的example。

基本实现：

public class Post extends ParseObject implements Serializable, Parcelable {
    ...

    public int describeContents() {
        return 0;
    }

    public void writeToParcel(Parcel out, int flags) {
        out.writeString(getId());
        out.writeSring(getUsername());
        ...
    }

    public static final Parcelable.Creator<Post> CREATOR
        = new Parcelable.Creator<Post>() {
            public Post createFromParcel(Parcel in) {
                return new Post(in);
            }

            public Post[] newArray(int size) {
                return new Post[size];
            }
    };

    private Post(Parcel in) {
        // Items must be read in the order they were written.
        setId(in.readString());
        setUsername(in.readString());
        ...
    }
}

试穿一下，希望对你有帮助。

Answer 2

将活动用作传输机制。

为要实现的活动创建一个接口，活动在实例化时将其传递给片段。每当您要传输数据时，请调用接口的回调。与它需要与之交互的片段进行协调，然后将您的数据发布到另一个将链接到片段的回调中。

如果所有这些都太复杂，那么只需使用 Otto 并享受随处发送事件，而不必担心在配置更改时分离/附加接口/侦听器。