如何从Firebase RecyclerView中删除项目 [英] How to remove items from firebase RecyclerView
问题描述
我目前正在Firebase RecyclerView的帮助下进行添加朋友"，如果用户点击添加"按钮，他将被添加到数据库n中，则需要永久删除所窃听的项目..因此，如何实现通过firebase模型，因为我们没有要删除的任何数据列表.
I'm currently working on Adding Friends with the help of firebase RecyclerView in which if a user tap on ADD button, he is added in database n that tapped item is needed to be removed permanently.. so, how to achieve it through firebase model as we dont have any data list to remove from..
这是代码
@Override
public void onStart(){
super.onStart();
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(mContext);
EmailPref=prefs.getString("EmailPref", EmailPref);
if(EmailPref!=null){
final Firebase ref = new Firebase(constants.FIREBASE_URL+"rootssahaj/authGplus");
FirebaseRecyclerAdapter<FriendsData,FriendsViewHolder> adapter=new FirebaseRecyclerAdapter<FriendsData, FriendsViewHolder>(
FriendsData.class,
R.layout.chat_view_list,
FriendsViewHolder.class,
ref
) {
@TargetApi(Build.VERSION_CODES.KITKAT)
@Override
protected void populateViewHolder(FriendsViewHolder friendsViewHolder, FriendsData s, int position) {
String key = this.getRef(position).getKey();
Log.e("SahajLOG", "String Keyyy " + key + " n EmailPref" + EmailPref);
if (!Objects.equals(key, EmailPref)) {
friendsViewHolder.mName.setText(s.getUserNAME());
Picasso.with(context).load(s.getPicurl()).transform(new CircleTransform()).into(friendsViewHolder.mImageProfile);
String keylocal = key;
Log.e("pavan", "Populate AddF key" + keylocal+" " + position);
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(mContext);
prefs.getString("keylocal" + position, keylocal + position);
if (keylocal != null) {
prefs.edit().putString("keylocal" + position, keylocal + position).commit();
}
} else {
friendsViewHolder.mCardView.setVisibility(View.GONE);
//friendsViewHolder.setVisibility(View.GONE);
}
}
};
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
recyclerView.setItemAnimator(new SlideInLeftAnimator());
recyclerView.getItemAnimator().setAddDuration(1000);
recyclerView.getItemAnimator().setRemoveDuration(1000);
recyclerView.getItemAnimator().setMoveDuration(1000);
recyclerView.getItemAnimator().setChangeDuration(1000);
SlideInLeftAnimator animator = new SlideInLeftAnimator();
animator.setInterpolator(new OvershootInterpolator());
recyclerView.setItemAnimator(animator);
AlphaInAnimationAdapter alphaAdapter = new AlphaInAnimationAdapter(adapter);
alphaAdapter.setDuration(500);
alphaAdapter.setInterpolator(new OvershootInterpolator(.5f));
alphaAdapter.setFirstOnly(false);
recyclerView.setAdapter(new ScaleInAnimationAdapter(alphaAdapter));
}
}
public class FriendsViewHolder extends RecyclerView.ViewHolder{
ImageView mImageProfile;
android.widget.TextView mName;
private int mVisibility;
Boolean CallAdd=false;
Button mAdd;
String keylocal;
CardView mCardView;
public FriendsViewHolder(View itemView) {
super(itemView);
mCardView=(CardView)itemView.findViewById(R.id.cardView);
mImageProfile=(ImageView)itemView.findViewById(R.id.profilePICC);
mName=(android.widget.TextView)itemView.findViewById(R.id.NameUSER);
context = itemView.getContext();
mAdd=(Button)itemView.findViewById(R.id.addButton);
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
if(prefs.getBoolean("CallAdd", CallAdd)){
AddaddButton();
}
mAdd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(mContext);
EmailPref = prefs.getString("EmailPref", EmailPref);
keylocal=prefs.getString("keylocal"+getAdapterPosition(),keylocal+getAdapterPosition());
final Firebase mFirebaseRef = new Firebase(constants.FIREBASE_URL + "rootssahaj/authGplus/"+ EmailPref);
mFirebaseRef.child("friends").child(keylocal).setValue("true");
Log.e("pavan", "Chat Adapter " + EmailPref + keylocal + " final key: " + keylocal);
//remove(getAdapterPosition());
}
});
}
public void AddaddButton(){
if (mAdd.getVisibility() == View.INVISIBLE) {
mAdd.setVisibility(View.VISIBLE);
}
}
}
推荐答案
如果您查看此代码，则在以下情况下会从Firebase中删除注释: 单击便笺.如果您了解Firebase查询，这似乎很简单.一旦正确设置了RecyclerView适配器，这还将更新RecyclerView.您不需要数据列表，只需要删除要删除的数据(例如ID或密钥)的值即可.
If you look at this code, it removes a Note from Firebase when the Note is clicked. It seems straight forward if you understand a Firebase query. This will also update the RecyclerView once the RecyclerView adapter is setup correctly. You don't need a List of data, just the value of what you want to remove, like an ID or a key.
@Override
public void onLongClick(View v, int i) {
mquery.orderByChild("text")
.equalTo((String) notes.get(i).getName())
.addListenerForSingleValueEvent(new ValueEventListener() {
public void onDataChange(DataSnapshot dataSnapshot) {
if (dataSnapshot.hasChildren()) {
DataSnapshot firstChild = dataSnapshot.getChildren().iterator().next();
firstChild.getRef().removeValue();
}
}
public void onCancelled(FirebaseError firebaseError) {
}
});
FirebaseRecyclerAdapter.class中的一个片段，该片段从Firebase中删除了该值并更新了recyclerView:
The FirebaseRecyclerAdapter.class from https://github.com/mmazzarolo/firebase-recyclerview works.
I just copied and pasted, for the most part. This is an abstract class you can use to make a RecyclerView adapter for your Firebase database. All the code is on that GitHub repository for you. Here is a snippet from FirebaseRecyclerAdapter.class that removes the value from Firebase AND updates the recyclerView:
@Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
String key = dataSnapshot.getKey();
if (mKeys.contains(key)) {
int index = mKeys.indexOf(key);
T item = mItems.get(index);
mKeys.remove(index);
mItems.remove(index);
notifyItemRemoved(index);
itemRemoved(item, key, index);
}
}
更新:您可以在RecyclerView适配器的Viewholder中隐藏视图.在stackoverflow中查看以下答案在RecyclerView中隐藏视图
UPDATE: You can hide a view in the Viewholder of the RecyclerView adapter. look at these answers in stackoverflow Hiding views in RecyclerView
这篇关于如何从Firebase RecyclerView中删除项目的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
