我无法从Firebase检索数据并在recyclerView上查看它
这是我在Firebase上的数据库enter image description here
没有问题出现，但是在我的跑步中没有显示这是我的跑步enter image description here
这是我的代码，我尝试了所有不知道是什么问题对我有帮助
public class account_preview extends AppCompatActivity {
private ArrayList<outflow>outflows;
private RecyclerView recyclerView;
RecyclerAdapter adapter;
DatabaseReference myRef;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_account_preview);
FirebaseDatabase database = FirebaseDatabase.getInstance();
myRef =
database.getReference("user_account/(username)/bank_accounts/1");
adapter = new RecyclerAdapter(outflows, account_preview.this);
recyclerView = (RecyclerView) findViewById(R.id.RecyclerView);
recyclerView.setHasFixedSize(true);
LinearLayoutManager llm = new LinearLayoutManager(this);
recyclerView.setLayoutManager(llm);
llm.setOrientation(LinearLayoutManager.VERTICAL);
onStart();
new GetDataFromFirebase().
executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
// Read from the database
recyclerView.setAdapter(adapter);
}
@Override
protected void onStart() {
super.onStart();
myRef.child("outflow").child("1").addValueEventListener(new
ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
outflows=new ArrayList<outflow>();
for (DataSnapshot dataSnapshot1:
dataSnapshot.getChildren()){
outflow values =
dataSnapshot1.getValue(outflow.class);
outflows.add(values);}
adapter.notifyDataSetChanged();
}
@Override
public void onCancelled(DatabaseError error) {
// Failed to read value
System.out.println("Failed to read value." +
error.toException());
}
});
}
private class GetDataFromFirebase extends
AsyncTask<Void,Void,Boolean>{
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected Boolean doInBackground(Void... voids) {
return false;
}
@Override
protected void onPostExecute(Boolean aBoolean) {
super.onPostExecute(aBoolean);
}
}
}
public class RecyclerAdapter extends
RecyclerView.Adapter<RecyclerAdapter.ViewHolder>{
private Context context;
private ArrayList<outflow> values;
public RecyclerAdapter(ArrayList<outflow> values, account_preview
context) {
this.values = values;
this.context = context;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
{
return new ViewHolder(LayoutInflater.from(parent.getContext())
.inflate(R.layout.list_outflows, parent, false));
}
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.name.setText( values.get(position).getCategory());
holder.c.setText((int) values.get(position).getAmount());
}
@Override
public int getItemCount() {
int arr = 0;
try{
if(values.size()==0){
arr = 0;
}
else{
arr=values.size();
}
}catch (Exception e){
}
return arr;
}
public class ViewHolder extends RecyclerView.ViewHolder {
private TextView name,c;
ViewHolder(View itemView) {
super(itemView);
name = (TextView) itemView.findViewById(R.id.totaloutflow);
c=(TextView)itemView.findViewById(R.id.total);
}
}
}
公共类流出{
private double amount;
private String date;
private String time;
private String attachment;
private String category;
private String location;
private String vendor;
private int rate;
public outflow(double amount, String date, String time, String attachment, String category, String location, String vendor) {
this.amount = amount;
this.date = date;
this.time = time;
this.attachment = attachment;
this.category = category;
this.location = location;
this.vendor = vendor;
}
public double getAmount() {
return amount;
}
public void setAmount(double amount) {
this.amount = amount;
}
public String getDate() {
return date;
}
public void setDate(String date) {
this.date = date;
}
public String getTime() {
return time;
}
public void setTime(String time) {
this.time = time;
}
public String getAttachment() {
return attachment;
}
public void setAttachment(String attachment) {
this.attachment = attachment;
}
public String getCategory() {
return category;
}
public void setCategory(String category) {
this.category = category;
}
public String getLocation() {
return location;
}
public void setLocation(String location) {
this.location = location;
}
public String getVendor() {
return vendor;
}
public void setVendor(String vendor) {
this.vendor = vendor;
}
public int getRate() {
return rate;
}
public void setRate(int rate) {
this.rate = rate;
}
}
activity_account_preview.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<android.support.v7.widget.RecyclerView
android:id="@+id/RecyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>
</android.support.constraint.ConstraintLayout>
list_outflows.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".account_preview">
<android.support.design.widget.BottomNavigationView
android:id="@+id/navigation"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:background="#27233A"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:menu="@menu/navigation" />
<TextView
android:id="@+id/textView"
android:layout_width="84dp"
android:layout_height="44dp"
android:layout_marginEnd="36dp"
android:layout_marginStart="8dp"
android:padding="5dp"
android:text="(التاريخ)"
android:textColor="#000000"
android:textSize="20dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintStart_toStartOf="parent"
tools:layout_editor_absoluteY="64dp"
tools:ignore="MissingConstraints" />
<Button
android:id="@+id/button"
android:layout_width="251dp"
android:layout_height="61dp"
android:layout_marginBottom="24dp"
android:layout_marginEnd="8dp"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:background="#9FB4C7"
android:text="حذف الحساب"
android:textColor="#ffffff"
android:textSize="30dp"
app:layout_constraintBottom_toTopOf="@+id/navigation"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.437"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView" />
<android.support.design.widget.FloatingActionButton
android:id="@+id/floatingActionButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="12dp"
android:layout_marginEnd="8dp"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginStart="8dp"
android:background="#D6C9C9"
android:clickable="true"
app:backgroundTint="#D6C9C9"
app:layout_constraintBottom_toTopOf="@+id/navigation"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.976"
app:layout_constraintStart_toStartOf="parent"
app:srcCompat="@android:drawable/ic_input_add" />
<android.support.v7.widget.CardView
android:id="@+id/card_view"
android:layout_width="392dp"
android:layout_height="64dp"
android:layout_margin="2.5dp"
android:layout_marginBottom="8dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="184dp"
app:cardBackgroundColor="@color/lightgrey"
app:cardCornerRadius="4dp"
app:layout_constraintBottom_toTopOf="@+id/button"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView"
app:layout_constraintVertical_bias="1.0"
tools:ignore="MissingConstraints">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:layout_weight="0.30"
android:orientation="vertical">
<TextView
android:id="@+id/totaloutflow"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="4dp"
android:text="الفواتير"
android:textColor="@color/colorPrimaryDark"
android:textSize="25sp" />
<TextView
android:id="@+id/total"
android:layout_width="388dp"
android:layout_height="wrap_content"
android:layout_marginLeft="4dp"
android:layout_marginStart="4dp"
android:text="ريال سعودي"
android:textSize="15sp"
android:textStyle="bold" />
</LinearLayout>
</android.support.v7.widget.CardView>
</android.support.constraint.ConstraintLayout>
答案 0 :(得分：0)
Firebase拥有自己的RecyclerView适配器，因此请更好地使用它。
public FirebaseRecyclerAdapter<taskdata, ShowDataViewHolder> getmFirebaseAdapter() {
return mFirebaseAdapter;
}
public void setmFirebaseAdapter(FirebaseRecyclerAdapter<taskdata, ShowDataViewHolder> mFirebaseAdapter) {
this.mFirebaseAdapter = mFirebaseAdapter;
}
//View Holder For Recycler View
public static class ShowDataViewHolder extends RecyclerView.ViewHolder {
private final TextView image_title ;
public ShowDataViewHolder(final View itemView)
{
super(itemView);
image_title = itemView.findViewById(R.id.taskname);
}
private void Image_Title(String title)
{
image_title.setText(title);
}
}
@Override
public void onStart() {
super.onStart();
FirebaseAuth mauth = FirebaseAuth.getInstance();
String userod = mauth.getCurrentUser().getUid();
myref = FirebaseDatabase.getInstance().getReference("Yourself").child(userod).child("task");
setmFirebaseAdapter(new FirebaseRecyclerAdapter<taskdata, ShowDataViewHolder>(
taskdata.class, R.layout.taskitem, ShowDataViewHolder.class, myref.orderByValue()) {
public void populateViewHolder(final ShowDataViewHolder viewHolder, taskdata model, final int position) {
viewHolder.Image_Title(model.getTaskname());
}
});
recyclerView.setAdapter(getmFirebaseAdapter());
myref.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
if(dataSnapshot.getValue() == null){
Toast.makeText(getContext(),"No Bookmarks added yet!",Toast.LENGTH_SHORT).show();
}else {
mFirebaseAdapter.notifyItemChanged(0);
mFirebaseAdapter.notifyDataSetChanged();
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
mFirebaseAdapter.notifyItemInserted(taskdata2.size()-1);
}
如果您需要有关代码的更多帮助，请访问我的github-https://github.com/afreakyelf/Yourself/blob/master/app/src/main/java/com/example/rajat/yourself/taskadapterhome.java
答案 1 :(得分：0)
要解决此问题，请在构造函数中添加以下代码行：
public RecyclerAdapter(List<outflow> list, account_preview context) {
this.list = list
this.context = context
}