【发布时间】:2020-05-13 13:18:49
【问题描述】:
我想在 Recyclerview 中显示数据。这一直有效,直到滚动时到达列表的末尾。问题是我可以在没有任何数据的情况下无休止地向下滚动。如果我想再次向上滚动,这些行会以很大的空间显示。
如果有人能帮助我,那就太好了!
这是片段显示数据的代码:
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
import java.util.List;
public class UserAbrechAdapter extends RecyclerView.Adapter<UserAbrechAdapter.ViewHolder> {
List<Abrechnung> abrechnung;
Context mContext;
public UserAbrechAdapter(Context context, ArrayList<Abrechnung> list) {
mContext = context;
abrechnung = list;
}
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(mContext).inflate(R.layout.adapter_abrech, parent, false);
ViewHolder viewHolder = new ViewHolder(view);
return viewHolder;
}
@Override
public void onBindViewHolder(@NonNull final ViewHolder holder, int position) {
holder.item_betrag.setText(String.valueOf(abrechnung.get(position).getBetrag()));
holder.item_datum.setText(abrechnung.get(position).getDatum());
holder.item_partner.setText(abrechnung.get(position).getTransaktionspartner());
holder.item_typ.setText(abrechnung.get(position).getTyp());
}
@Override
public int getItemCount() {
return abrechnung.size();
}
public static class ViewHolder extends RecyclerView.ViewHolder {
private TextView item_typ, item_betrag, item_datum, item_partner;
public ViewHolder(@NonNull View itemView) {
super(itemView);
item_typ = itemView.findViewById(R.id.typ);
item_betrag = itemView.findViewById(R.id.wert);
item_datum = itemView.findViewById(R.id.datum);
item_partner = itemView.findViewById(R.id.partner);
}
}
}
这是片段布局的 XML 代码:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/hintergrund">
<TextView
android:id="@+id/betrag"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_marginTop="52dp"
android:fontFamily="@font/segoeui_standard"
android:text="@string/user_geld_Betrag"
android:textColor="@color/weiße_schrift"
android:textSize="20sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.498"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/bestellung"
android:layout_width="wrap_content"
android:layout_height="31dp"
android:layout_marginStart="44dp"
android:layout_marginTop="52dp"
android:fontFamily="@font/segoeui_standard"
android:text="@string/user_typ_transaktion"
android:textColor="@color/weiße_schrift"
android:textSize="20sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/datum"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="52dp"
android:layout_marginEnd="32dp"
android:fontFamily="@font/segoeui_standard"
android:text="@string/user_datum_transaktion"
android:textColor="@color/weiße_schrift"
android:textSize="20sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0" />
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/recyclerview_scroll"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintTop_toBottomOf="@+id/betrag"
app:layout_constraintVertical_bias="0.051"
tools:layout_editor_absoluteX="0dp">
</androidx.recyclerview.widget.RecyclerView>
</androidx.constraintlayout.widget.ConstraintLayout>
这是订单项的 XML:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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:layout_width="match_parent"
android:layout_height="match_parent"
>
<TextView
android:id="@+id/typ"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="24dp"
android:gravity="center"
android:text="TextView"
app:layout_constraintBottom_toTopOf="@+id/partner"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="@+id/wert"
app:layout_constraintVertical_bias="0.85" />
<TextView
android:id="@+id/partner"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="25dp"
android:gravity="center"
android:text="TextView"
app:layout_constraintStart_toStartOf="@+id/typ"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/wert"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:text="TextView"
app:layout_constraintBottom_toTopOf="@+id/partner"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="@+id/datum"
app:layout_constraintVertical_bias="1.0" />
<TextView
android:id="@+id/datum"
android:layout_width="wrap_content"
android:layout_height="30dp"
android:layout_marginTop="4dp"
android:layout_marginEnd="24dp"
android:text="TextView"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
【问题讨论】:
-
你的数据库是什么类型的?
-
我使用的是 Firebase,它不是实时数据库
标签: java android firebase android-recyclerview google-cloud-firestore