Question

我制作了一个简单的应用程序，显示校园周围发生的当地事件。每个活动都在Cardview中保存，看起来像this。红色方块是图标的占位符，用于显示此类事件。

我想更改ImageView（红色方块），具体取决于值子字符串的值。因此，如果孩子的字符串值＆＃34;类别＆＃34;是＆＃34;音乐＆＃34;，将显示音符图标而不是红色方块等。我知道我可以使用switch语句手动读取该子项的值，然后设置ImageView基于字符串值，但我不知道将它放在我的代码中的位置，或者这是否是最好的方法。您有什么推荐的吗？这是片段的代码：

    public class EventsFragment extends Fragment {
    public String postKey;


    public static class EventViewHolder extends RecyclerView.ViewHolder{
        public TextView eventTitle;
        public ImageView eventImage;
        public ImageView eventCategory;
        public TextView eventDate;
        View mView;

        public EventViewHolder(View v){
            super(v);
            mView = v;
            eventTitle = (TextView)mView.findViewById(R.id.title);
            eventImage = (ImageView)mView.findViewById(R.id.image);
            eventCategory = (ImageView)mView.findViewById(R.id.category);
            eventDate = (TextView)mView.findViewById(R.id.date);
        }

        public TextView getEventTitle() {
            return eventTitle;
        }

        public void setEventTitle(TextView eventTitle) {
            this.eventTitle = eventTitle;
        }
    }

    private DatabaseReference mFirebaseDatabaseReference;
    private FirebaseRecyclerAdapter<ModelClass, EventViewHolder>   mFirebaseAdapter;
    private RecyclerView mEventRecyclerView;
    private LinearLayoutManager mLinearLayoutManager;
    private static String TAG = "EventsFragment";
    public static final String DATA = "Data";

    //VARIABLES
    private RecyclerView mBlogList;
    private FirebaseDatabase database;
    private DatabaseReference ref;


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        final View v = inflater.inflate(R.layout.events_fragment,container,false);
        v.setTag(TAG);
//RV
        mEventRecyclerView = (RecyclerView)v.findViewById(R.id.events_list);
        //LLM
        mLinearLayoutManager = new LinearLayoutManager(getActivity());
        mEventRecyclerView.setLayoutManager(mLinearLayoutManager);
        //DB
        mFirebaseDatabaseReference = FirebaseDatabase.getInstance().getReference();
        mFirebaseAdapter = new FirebaseRecyclerAdapter<ModelClass, EventViewHolder>(
                ModelClass.class,
                R.layout.design_row,
                EventViewHolder.class,
                mFirebaseDatabaseReference.child(DATA))
        {
            @Override
            protected void populateViewHolder(EventViewHolder viewHolder, ModelClass model, final int position) {

                final String post_key = getRef(position).getKey();




                viewHolder.eventDate.setText(model.getDate());
                viewHolder.eventTitle.setText(model.getTitle());
                Picasso.with(getActivity().getApplicationContext())
                        .load(model.getImage())
                        .fit()
                        .into(viewHolder.eventImage);



                viewHolder.mView.setOnClickListener(new View.OnClickListener() {

                    @Override
                    public void onClick(View view) {



                        setPostKey(post_key);

                        mFirebaseDatabaseReference.child(DATA).child(post_key).addValueEventListener(new ValueEventListener() {

                            String post_info, post_title, post_image, post_category;

                            @Override
                            public void onDataChange(DataSnapshot snapshot) {
                                System.out.println(snapshot.getValue());
                                post_info = snapshot.child("info").getValue().toString();
                                post_title = snapshot.child("title").getValue().toString();
                                post_image = snapshot.child("image").getValue().toString();
                                post_category = snapshot.child("category").getValue().toString();

                                Bundle bundle = new Bundle();
                                bundle.putString("info", post_info);
                                bundle.putString("title", post_title);
                                bundle.putString("image", post_image);

                                FragmentManager fragM = getActivity().getSupportFragmentManager();
                                FragmentTransaction fragT = fragM.beginTransaction();

                                EventsExpandedFragment expand = new EventsExpandedFragment();
                                expand.setArguments(bundle);

                                fragT.replace(R.id.frame, expand);
                                fragT.addToBackStack("");
                                fragT.commit();


                            }

                            @Override
                            public void onCancelled(DatabaseError databaseError) {

                            }
                        });

                    }
                });
            }


        };

        mEventRecyclerView.setLayoutManager(mLinearLayoutManager);
        mEventRecyclerView.setAdapter(mFirebaseAdapter);

        return v;
    }

    public String getPostKey() {
        return postKey;
    }

    public void setPostKey(String postKey) {
        this.postKey = postKey;
    }






}

这是一个完整的截图供参考：

Answer 1

我认为你应该把switch语句放在populateViewHolder

上

@Override
protected void populateViewHolder(EventViewHolder viewHolder, ModelClass model, final int position) {

      switch (model.eventCategory) {
          case "eventType1": {
              //load your event category image
          }
          case "eventType2": {
              //load your event category image
          }
          default:
              break;
      }

      // other actions
}

这回答你的问题吗？

如何根据Firebase子字符串值为Cardview设置图标？

1 个答案: