java - 当我单击recyclerView时如何从Firestore中获取数据？

Question

我已经从Firestore检索数据到RecyclerView。当用户单击RecyclerView的任何项目时，他将进入Click Post活动。在点击发布活动中，应显示回收站项目的海报图像和描述。我怎么做？



以下是MainActivity的代码。

public class HomeActivity extends AppCompatActivity {    

private RecyclerView postList;
FirebaseAuth firebaseAuth;
StorageReference storageReference;
FirebaseFirestore db;
DocumentReference documentReference;
private String userid;        

 @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_home);

    firebaseAuth = FirebaseAuth.getInstance();
    userid = firebaseAuth.getCurrentUser().getUid();
    FirebaseFirestore db = FirebaseFirestore.getInstance();
    documentReference = db.collection("posts").document();

    postList = (RecyclerView) findViewById(R.id.all_user_post_list);
    postList.setHasFixedSize(true);
    LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
    linearLayoutManager.setReverseLayout(true);
    linearLayoutManager.setStackFromEnd(true);
    postList.setLayoutManager(linearLayoutManager);}

private void DisplayAllUsersPosts() {

    FirebaseFirestore db = FirebaseFirestore.getInstance();
    Query query = db.collection("posts");

    FirestoreRecyclerOptions<Posts> options = new FirestoreRecyclerOptions.Builder<Posts>()
            .setQuery(query, Posts.class)
            .build();

    FirestoreRecyclerAdapter adapter = new FirestoreRecyclerAdapter<Posts, PostsViewHolder>(options) {


        @Override
        protected void onBindViewHolder(@NonNull PostsViewHolder holder, int position, @NonNull Posts model) {
            holder.setTime(model.getTime());
            holder.setDate(model.getDate());
            holder.setDescription(model.getDescription());
            holder.setPostimage(model.getPostimage());
            holder.setProfileimage(model.getProfileimage());
            holder.setFullname(model.getFullname());


            holder.mView.setOnClickListener(new View.OnClickListener(){
                    @Override
                    public void onClick(View v){

                    Intent clickPostIntent = new Intent(HomeActivity.this, ClickPostActivity.class);
             clickPostIntent.putExtra("image", model.getPostimage());
            clickPostIntent.putExtra("description", model.getDescription());
                    startActivity(clickPostIntent);
                    }


                });

        }

        @Override
        public PostsViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            View view = LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.all_posts_layout, parent, false);

            return new PostsViewHolder(view);
        }

    };
    adapter.startListening();
    postList.setAdapter(adapter);

}


public static class PostsViewHolder extends RecyclerView.ViewHolder{
    View mView;

    String userid;

    public PostsViewHolder(View itemView){
        super(itemView);
        mView = itemView;

        userid=FirebaseAuth.getInstance().getCurrentUser().getUid();

    }


    public  void  setTime(String time){
        TextView PostTime = (TextView) mView.findViewById(R.id.post_time);
        PostTime.setText(""+ time);
    }

    public  void  setDate(String date){
        TextView PostDate = (TextView) mView.findViewById(R.id.post_date);
        PostDate.setText(" "+date);
    }


    public  void  setDescription(String description){
        TextView PostDescription = (TextView) mView.findViewById(R.id.click_post_description);
        PostDescription.setText(description);
    }

    public  void  setPostimage(String postimage){
        ImageView PostImage = (ImageView) mView.findViewById(R.id.click_post_image);
        Picasso.get().load(postimage).into(PostImage);
    }

    public  void  setProfileimage(String profileimage){
        CircleImageView image = (CircleImageView) mView.findViewById(R.id.post_profile_image);
        Picasso.get().load(profileimage).into(image);
    }
    public  void  setFullname(String fullname){
        TextView username = (TextView) mView.findViewById(R.id.post_user_name);
        username.setText(fullname);
    }


}

以下是点击后活动的代码

public class ClickPostActivity extends AppCompatActivity {

    private Toolbar mToolbar;
FirebaseAuth firebaseAuth;
StorageReference storageReference;
FirebaseFirestore db;
private String userid;
private ImageView postImage;
private TextView postDescription;
private Button deletePostButton;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_click_post);

    firebaseAuth = FirebaseAuth.getInstance();
    userid = firebaseAuth.getCurrentUser().getUid();
    FirebaseFirestore db = FirebaseFirestore.getInstance();

    postImage = (ImageView) findViewById(R.id.click_post_image);
    postDescription = (TextView) findViewById(R.id.click_post_description);
    deletePostButton = (Button) findViewById(R.id.deletepost);

    DocumentReference docRef = db.collection("posts").document();

    docRef.addSnapshotListener(new EventListener<DocumentSnapshot>() {
        @Override
        public void onEvent(@Nullable DocumentSnapshot documentSnapshot, @Nullable FirebaseFirestoreException e) {
            if(documentSnapshot.exists()){
                String postimage = documentSnapshot.getString("postimage");
                String description = documentSnapshot.getString("description");

                Picasso.get().load(postimage).into(postImage);
                postDescription.setText(description);
            }
        }
    });



}

}

Answer 1

在创建新活动之前，获取包含图像和描述的文档，并将它们传递给活动。应该是这样的：

            holder.mView.setOnClickListener(new View.OnClickListener(){
                @Override
                public void onClick(View v){

                  DocumentReference docRef = db.collection("posts").document();

                  docRef.addSnapshotListener(new EventListener<DocumentSnapshot>() {
                  @Override
                  public void onEvent(@Nullable DocumentSnapshot documentSnapshot, @Nullable FirebaseFirestoreException e) {
                      if(documentSnapshot.exists()){
                          String postimage = documentSnapshot.getString("postimage");
                          String description = documentSnapshot.getString("description");

                             Intent clickPostIntent = new Intent(HomeActivity.this, ClickPostActivity.class);
                             clickPostIntent.putExtra("image", postimage);
                             clickPostIntent.putExtra("description", description);
                             startActivity(clickPostIntent);
                      }
                 }
                 });
                }
            });

在ClickPost活动中：

public class ClickPostActivity extends AppCompatActivity {

private Toolbar mToolbar;
FirebaseAuth firebaseAuth;
StorageReference storageReference;
FirebaseFirestore db;
private String userid;
private ImageView postImage;
private TextView postDescription;
private Button deletePostButton;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_click_post);

    firebaseAuth = FirebaseAuth.getInstance();
    userid = firebaseAuth.getCurrentUser().getUid();
    FirebaseFirestore db = FirebaseFirestore.getInstance();

    postImage = (ImageView) findViewById(R.id.click_post_image);
    postDescription = (TextView) findViewById(R.id.click_post_description);
    deletePostButton = (Button) findViewById(R.id.deletepost);

    Bundle bundle = getIntent().getExtras();
    String image = bundle.getString("image");
    String description = bundle.getString("description");

    Picasso.get().load(image).into(postImage);
    postDescription.setText(description);
}