代码
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_contacts, container, false);
noUsersText = (TextView) rootView.findViewById(R.id.noUsersText);
mUsersList = (RecyclerView) rootView.findViewById(R.id.usersList);
mAuth = FirebaseAuth.getInstance();
currentUser = mAuth.getCurrentUser();
UID = mAuth.getCurrentUser().getUid();
mDatabaseReference = FirebaseDatabase.getInstance().getReference().child("Users");
mProgressDialogue = new ProgressDialog(getActivity());
mProgressDialogue.setMessage("Loading...");
mProgressDialogue.show();
mUsersList.setLayoutManager(new LinearLayoutManager(getActivity()));
FirebaseRecyclerOptions<AllUsers> options =
new FirebaseRecyclerOptions.Builder<AllUsers>()
.setQuery(mDatabaseReference, AllUsers.class)
.build();
firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<AllUsers, UsersViewHolder>(options) {
@Override
protected void onBindViewHolder(@NonNull UsersViewHolder holder, int position, @NonNull AllUsers model) {
holder.setName(model.getName());
holder.setStatus(model.getStatus());
final String userId = getRef(position).getKey();
holder.mView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference().child("Users").child(userId).child("Data");
rootRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
userName = dataSnapshot.child("Name").getValue().toString();
Intent intent = new Intent(getActivity(), Chat.class);
intent.putExtra("Recievers_Id", userId);
intent.putExtra("Recievers_Name", userName);
startActivity(intent);
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
});
}
@Override
public UsersViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.all_users_layout, parent, false);
return new UsersViewHolder(view);
}
};
mUsersList.setAdapter(firebaseRecyclerAdapter);
return rootView;
}
public static class UsersViewHolder extends RecyclerView.ViewHolder{
View mView;
public UsersViewHolder(View itemView) {
super(itemView);
mView = itemView;
}
public void setName(String name) {
TextView mDisplayName = (TextView) mView.findViewById(R.id.display_name);
mDisplayName.setText(name);
}
public void setStatus(String status) {
TextView mDisplayStatus = (TextView) mView.findViewById(R.id.display_status);
mDisplayStatus.setText(status);
}
}
@Override
public void onStart() {
super.onStart();
firebaseRecyclerAdapter.startListening();
}
@Override
public void onStop() {
super.onStop();
if(firebaseRecyclerAdapter != null) {
firebaseRecyclerAdapter.stopListening();
}
}
}
数据库 - https://ibb.co/kLNqxd
当我的数据库结构为Users/userid/'all the data'时，它运行正常。现在我又添加了一个名为Data的子项，它没有显示数据。有人可以帮帮我吗？
尝试以下2种方法后出错
Process: com.appmaster.akash.messageplus, PID: 15314
com.google.firebase.database.DatabaseException: Can't convert object of type java.lang.String to type com.appmaster.akash.messageplus.HomeScreen_Contacts$UserData
at com.google.android.gms.internal.zzear.zzb(Unknown Source)
at com.google.android.gms.internal.zzear.zza(Unknown Source)
at com.google.firebase.database.DataSnapshot.getValue(Unknown Source)
at com.firebase.ui.database.ClassSnapshotParser.parseSnapshot(ClassSnapshotParser.java:23)
at com.firebase.ui.database.ClassSnapshotParser.parseSnapshot(ClassSnapshotParser.java:14)
at com.firebase.ui.common.BaseCachingSnapshotParser.parseSnapshot(BaseCachingSnapshotParser.java:32)
at com.firebase.ui.common.BaseObservableSnapshotArray.get(BaseObservableSnapshotArray.java:45)
at com.firebase.ui.database.FirebaseRecyclerAdapter.getItem(FirebaseRecyclerAdapter.java:103)
at com.firebase.ui.database.FirebaseRecyclerAdapter.onBindViewHolder(FirebaseRecyclerAdapter.java:118)
at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6482)
at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6515)
at android.support.v7.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5458)
at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5724)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5563)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5559)
at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2229)
at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1556)
at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1516)
at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:608)
at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3693)
at android.support.v7.widget.RecyclerView.onMeasure(RecyclerView.java:3109)
at android.view.View.measure(View.java:18827)
at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:716)
at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:462)
at android.view.View.measure(View.java:18827)
at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1630)
at android.view.View.measure(View.java:18827)
at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:716)
at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:462)
at android.view.View.measure(View.java:18827)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5954)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:748)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:630)
at android.view.View.measure(View.java:18827)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5954)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:139)
at android.view.View.measure(View.java:18827)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5954)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:748)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:630)
at android.view.View.measure(View.java:18827)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5954)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
at android.view.View.measure(View.java:18827)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5954)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:748)
答案 0 :(得分：0)
要解决此问题，请更改以下代码行：
mDatabaseReference = FirebaseDatabase.getInstance().getReference().child("Users");
到
String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
mDatabaseReference = FirebaseDatabase.getInstance().getReference().child("Users").child(uid).child("Data");
答案 1 :(得分：0)
我最初的猜测是，您需要在班级中Data成员传递给FirebaseRecyclerAdapter。现在这个班级是AllUsers。因此，最简单的更改是为Data创建一个新类：
public class UserData {
public AllUsers Data;
}
所以这是一个简单的类，只有一个名为Data的公共字段，它匹配您在数据库中添加的Data属性。
使用以下内容将其连接到FirebaseRecyclerAdapter
mDatabaseReference = FirebaseDatabase.getInstance().getReference().child("Users");
FirebaseRecyclerOptions<UserData> options =
new FirebaseRecyclerOptions.Builder<UserData>()
.setQuery(mDatabaseReference, UserData.class)
.build();
firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<UserData, UsersViewHolder>(options) {
@Override
protected void onBindViewHolder(@NonNull UsersViewHolder holder, int position, @NonNull UserData model) {
holder.setName(model.Data.getName());
holder.setStatus(model.Data.getStatus());
...