Firebase recyclerViewAdpter无法正常工作

时间：2016-11-03 18:28:18

标签： android firebase firebase-realtime-database firebaseui

在我的博客应用程序中发布详细信息Activity我添加了评论列表，其中包含简单的RecyclerView适配器工作正常，但我无法添加删除按钮以进行评论，因此移至 FireBase < / strong> RecyclerView现在我有很多问题

  1. 它没有实时更新
  2. 当我评论在我关闭编辑文本框时没有弹出编辑文本布局时，它会显示我的评论
  3. 当我写评论并点击评论按钮时它没有显示评论但是当我在写完三四行后同时写第二条评论时，前一条评论弹出，编辑文本机器人隐藏在键盘下面为什么会发生这种情况< / LI>

    活动代码： 

    mCommentsRecycler.setLayoutManager(mlinearLayoutManager);


}
@Override
public void onStart() {
 super.onStart();

 // Add value event listener to the post
 // [START post_value_event_listener]
 ValueEventListener postListener = new ValueEventListener() {
  @Override
  public void onDataChange(DataSnapshot dataSnapshot) {
   // Get Post object and use the values to update the UI
   Post post = dataSnapshot.getValue(Post.class);
   // [START_EXCLUDE]
   // mAuthorView.setText(post.author);
   mTitleView.setText(post.title);
   mBodyView.setText(post.body);
   final String formImage = String.valueOf(post.postDetailPic);
   // [END_EXCLUDE]
   if (formImage.length() > 0) {
    Picasso.with(getApplicationContext()).load(formImage)
     .networkPolicy(NetworkPolicy.OFFLINE)
     .into(postPic, new Callback() {
      @Override
      public void onSuccess() {

      }

      @Override
      public void onError() {
       //Try again online if cache failed
       Picasso.with(getApplicationContext())
        .load(formImage)
        //.error(R.drawable.ic_warning_black_24dp)
        .into(postPic, new Callback() {
         @Override
         public void onSuccess() {

         }

         @Override
         public void onError() {
          Log.v("Picasso", "Could not fetch image");
         }
        });
      }
     });

   }

  }

  @Override
  public void onCancelled(DatabaseError databaseError) {
   // Getting Post failed, log a message
   Log.w(TAG, "loadPost:onCancelled", databaseError.toException());
   // [START_EXCLUDE]
   Toast.makeText(PostDetailActivity.this, "Failed to load post.",
    Toast.LENGTH_SHORT).show();
   // [END_EXCLUDE]
  }
 };
 mPostReference.addValueEventListener(postListener);
 // [END post_value_event_listener]

 // Keep copy of post listener so we can remove it when app stops
 mPostListener = postListener;


 // Listen for comments
 mAdapter = new CommentAdepter(Comment.class, CommentViewHolder.class, R.layout.item_comment, mCommentsReference, this);
 mCommentsRecycler.setAdapter(mAdapter);


}


@Override
public void onStop() {
 super.onStop();

 // Remove post value event listener
 if (mPostListener != null) {
  mPostReference.removeEventListener(mPostListener);
 }

 // Clean up comments listener
 mAdapter.cleanup();
}

@Override
public void onClick(View v) {
 int i = v.getId();
 if (i == R.id.button_post_comment) {
  postComment();
 }
}


private void postComment() {
 FirebaseUser mUser = FirebaseAuth.getInstance().getCurrentUser();
 assert mUser != null;
 final String uid = mUser.getUid();
 final DatabaseReference commentDb = FirebaseDatabase.getInstance().getReference().child("Users").child(uid);
 commentDb.addListenerForSingleValueEvent(new ValueEventListener() {
  @Override
  public void onDataChange(DataSnapshot dataSnapshot) {
   // Get user information
   User user = dataSnapshot.getValue(User.class);
   String authorName = user.name;
   String commentUserPic = user.ProfilePic;


   // Create new comment object
   String commentText = mCommentField.getText().toString();

   HashMap < String, Object > dateCreated; {

    //Otherwise make a new object set to ServerValue.TIMESTAMP
    dateCreated = new HashMap < String, Object > ();
    dateCreated.put("timeStamp", ServerValue.TIMESTAMP);

   }
   HashMap < String, Boolean > commenter_id; {
    commenter_id = new HashMap < String, Boolean > ();
    commenter_id.put(getUid(), true);
   }
   Comment comment = new Comment(uid, authorName, commentText, commentUserPic, dateCreated, commenter_id);

   // Push the comment, it will appear in the list
   mCommentsReference.push().setValue(comment);


   // Clear the field
   mCommentField.setText(null);

  }

  @Override
  public void onCancelled(DatabaseError databaseError) {

  }

 });

}

private String getUid() {
 return FirebaseAuth.getInstance().getCurrentUser().getUid();
}


private static class CommentViewHolder extends RecyclerView.ViewHolder {

 public CommentViewHolder(View itemView) {
  super(itemView);

  authorView = (TextView) itemView.findViewById(R.id.comment_author);
  bodyView = (TextView) itemView.findViewById(R.id.comment_body);
  postingTime = (TextView) itemView.findViewById(R.id.comment_post_time);
  rm_comment = (Button) itemView.findViewById(R.id.remove_comment);


 }

 public void setImage(String images) {
  this.imageDp = images;
  userPic = (ImageView) itemView.findViewById(R.id.comment_photo);
  Picasso.with(context).load(imageDp).into(userPic);
 }


 void bindToPost(Comment comment, View.OnClickListener starClickListener) {
  authorView.setText(comment.author);
  bodyView.setText(comment.text);
  setImage(comment.commentPic);
  setViewValue(comment.getTimestampCreatedLong());

  rm_comment.setOnClickListener(starClickListener);
 }

}




private class CommentAdepter extends FirebaseRecyclerAdapter < Comment, CommentViewHolder > {
 private Context mContext;
 private List < String > mCommentIds = new ArrayList < > ();
 private List < Comment > mComments = new ArrayList < > ();
 private String mkey;

 CommentAdepter(Class < Comment > CommentClass, Class < CommentViewHolder > viewHolderClass, int modelLayout, DatabaseReference ref, final Context context) {
  super(CommentClass, modelLayout, viewHolderClass, mCommentsReference);


  mContext = context;

  // Create child event listener
  // [START child_event_listener_recycler]
  ChildEventListener childEventListener = new ChildEventListener() {
   @Override
   public void onChildAdded(DataSnapshot dataSnapshot, String previousChildName) {
    Log.d(TAG, "onChildAdded:" + dataSnapshot.getKey());
    // A new comment has been added, add it to the displayed list
    Comment comment = dataSnapshot.getValue(Comment.class);
    // mkey = dataSnapshot.getKey();


    // [START_EXCLUDE]
    // Update RecyclerView
    mCommentIds.add(dataSnapshot.getKey());
    mComments.add(comment);
    notifyItemInserted(mComments.size() - 1);
    // [END_EXCLUDE]
   }

   @Override
   public void onChildChanged(DataSnapshot dataSnapshot, String previousChildName) {
    Log.d(TAG, "onChildChanged:" + dataSnapshot.getKey());

    // A comment has changed, use the key to determine if we are displaying this
    // comment and if so displayed the changed comment.
    Comment newComment = dataSnapshot.getValue(Comment.class);
    String commentKey = dataSnapshot.getKey();

    // [START_EXCLUDE]
    int commentIndex = mCommentIds.indexOf(commentKey);
    if (commentIndex > -1) {
     // Replace with the new data
     mComments.set(commentIndex, newComment);

     // Update the RecyclerView
     notifyItemChanged(commentIndex);
    } else {
     Log.w(TAG, "onChildChanged:unknown_child:" + commentKey);
    }
    // [END_EXCLUDE]
   }

   @Override
   public void onChildRemoved(DataSnapshot dataSnapshot) {
    Log.d(TAG, "onChildRemoved:" + dataSnapshot.getKey());

    // A comment has changed, use the key to determine if we are displaying this
    // comment and if so remove it.
    String commentKey = dataSnapshot.getKey();


    // [START_EXCLUDE]
    int commentIndex = mCommentIds.indexOf(commentKey);
    if (commentIndex > -1) {
     // Remove data from the list
     mCommentIds.remove(commentIndex);
     mComments.remove(commentIndex);

     // Update the RecyclerView
     notifyItemRemoved(commentIndex);
    } else {
     Log.w(TAG, "onChildRemoved:unknown_child:" + commentKey);
    }
    // [END_EXCLUDE]
   }

   @Override
   public void onChildMoved(DataSnapshot dataSnapshot, String previousChildName) {
    Log.d(TAG, "onChildMoved:" + dataSnapshot.getKey());

    // A comment has changed position, use the key to determine if we are
    // displaying this comment and if so move it.
    Comment movedComment = dataSnapshot.getValue(Comment.class);
    String commentKey = dataSnapshot.getKey();

    // ...

   }

   @Override
   public void onCancelled(DatabaseError databaseError) {
    Log.w("PostDetailActivity", "postComments:onCancelled", databaseError.toException());
    Toast.makeText(mContext, "Failed to load comments.",
     Toast.LENGTH_SHORT).show();
   }


  };

  ref.addChildEventListener(childEventListener);
  // [END child_event_listener_recycler]

  // Store reference to listener so it can be removed on app stop
 }


 @Override
 public int getItemCount() {
  return mComments.size();
 }

 @Override
 protected void populateViewHolder(final CommentViewHolder viewHolder, final Comment model, final int position) {
  final DatabaseReference commentRef = getRef(position);
  final String commentKey = commentRef.getKey();

  if (model.commenter_id.containsKey(gUid())) {
   viewHolder.rm_comment.setVisibility(View.VISIBLE);
  }
  viewHolder.bindToPost(model, new View.OnClickListener() {
   @Override
   public void onClick(View view) {
    Toast.makeText(mContext, "clicked  " + commentKey, Toast.LENGTH_SHORT).show();
    mCommentsReference.child(commentKey).removeValue();

   }
  });
 }

}

private String gUid() {
 return FirebaseAuth.getInstance().getCurrentUser().getUid();
}

}

    如果你需要布局文件，请评论....

1 个答案:

答案 0 :(得分：0)

我添加了删除FirebaseRecyclerAdapter中的项目的功能，并且通常遵循此帖子中的建议：

how to implement a SetOnItemClickListener FirebaseRecyclerViewAdapter

我使用了第一个解决方案，在populateViewHolder（）中添加了一个ImageView.setOnClickListener（）调用。它对我来说很好。

我不太清楚上面的＃3问题是什么，但我遇到了一个问题，即数据在第一次被调用时没有填充。我在这篇文章中找到了我的解决方案，即确保将RecyclerView高度设置为match_parent：

FirebaseRecyclerAdapter - populateViewHolder is not populating the data for first time it runs?

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