Java FirebaseRecyclerAdapter未在我的RecyclerView布局中显示数据
请注意,有很多这样的问题,但没有一个适合我。 我一直试图在回收器视图中显示数据,但它没有显示数据,也没有抛出任何错误 这是我的密码 我已经包括了最新版本的Firebase依赖项和最新版本的Firebase UI数据库 依赖项版本Java FirebaseRecyclerAdapter未在我的RecyclerView布局中显示数据,java,android,firebase,firebase-realtime-database,firebaseui,Java,Android,Firebase,Firebase Realtime Database,Firebaseui,请注意,有很多这样的问题,但没有一个适合我。 我一直试图在回收器视图中显示数据,但它没有显示数据,也没有抛出任何错误 这是我的密码 我已经包括了最新版本的Firebase依赖项和最新版本的Firebase UI数据库 依赖项版本 // Firebase implementation 'com.google.firebase:firebase-auth:19.2.0' implementation 'com.google.firebase:firebase-database:19.2.1' imp
// Firebase
implementation 'com.google.firebase:firebase-auth:19.2.0'
implementation 'com.google.firebase:firebase-database:19.2.1'
implementation 'com.google.firebase:firebase-storage:19.1.1'
// Firebase UI
implementation 'com.firebaseui:firebase-ui-database:6.0.2'
这是电影课
Films.java
package com.dipeshpatil.in;
public class Films {
public String name, year;
public Films(String name, String year) {
this.name = name;
this.year = year;
}
public Films() {
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getYear() {
return year;
}
public void setYear(String year) {
this.year = year;
}
}
这是ViewHolder类FilmsViewHolder.java
package com.dipeshpatil.in;
import android.view.View;
import android.widget.TextView;
import androidx.recyclerview.widget.RecyclerView;
public class FilmsViewHolder extends RecyclerView.ViewHolder {
public TextView mFilmName;
public TextView mFilmYear;
public FilmsViewHolder(View itemView){
super(itemView);
mFilmName = itemView.findViewById(R.id.user_single_name);
mFilmYear = itemView.findViewById(R.id.user_single_status);
}
}
public class FilmsActivity extends AppCompatActivity {
private RecyclerView mFilmsList;
private DatabaseReference mFilmsDatabase;
private FirebaseRecyclerOptions<Films> options;
private FirebaseRecyclerAdapter<Films, FilmsViewHolder> adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_films);
mFilmsList = findViewById(R.id.films_list);
mFilmsList.setHasFixedSize(true);
mFilmsDatabase = FirebaseDatabase.getInstance().getReference().child("Films");
options = new FirebaseRecyclerOptions.Builder<Films>()
.setQuery(mFilmsDatabase, Films.class)
.build();
adapter = new FirebaseRecyclerAdapter<Films, FilmsViewHolder>(options) {
@Override
protected void onBindViewHolder(FilmsViewHolder filmsViewHolder, int i, Films films) {
filmsViewHolder.mFilmName.setText(films.getName());
filmsViewHolder.mFilmYear.setText(films.getYear());
}
@NonNull
@Override
public FilmsViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View mView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.users_single_layout, parent, false);
return new FilmsViewHolder(mView);
}
};
mFilmsList.setAdapter(adapter);
}
@Override
protected void onStart() {
super.onStart();
adapter.startListening();
}
@Override
protected void onStop() {
super.onStop();
adapter.stopListening();
}
}
这是我应该在回收器视图中显示数据的活动FilmsActivity.java
package com.dipeshpatil.in;
import android.view.View;
import android.widget.TextView;
import androidx.recyclerview.widget.RecyclerView;
public class FilmsViewHolder extends RecyclerView.ViewHolder {
public TextView mFilmName;
public TextView mFilmYear;
public FilmsViewHolder(View itemView){
super(itemView);
mFilmName = itemView.findViewById(R.id.user_single_name);
mFilmYear = itemView.findViewById(R.id.user_single_status);
}
}
public class FilmsActivity extends AppCompatActivity {
private RecyclerView mFilmsList;
private DatabaseReference mFilmsDatabase;
private FirebaseRecyclerOptions<Films> options;
private FirebaseRecyclerAdapter<Films, FilmsViewHolder> adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_films);
mFilmsList = findViewById(R.id.films_list);
mFilmsList.setHasFixedSize(true);
mFilmsDatabase = FirebaseDatabase.getInstance().getReference().child("Films");
options = new FirebaseRecyclerOptions.Builder<Films>()
.setQuery(mFilmsDatabase, Films.class)
.build();
adapter = new FirebaseRecyclerAdapter<Films, FilmsViewHolder>(options) {
@Override
protected void onBindViewHolder(FilmsViewHolder filmsViewHolder, int i, Films films) {
filmsViewHolder.mFilmName.setText(films.getName());
filmsViewHolder.mFilmYear.setText(films.getYear());
}
@NonNull
@Override
public FilmsViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View mView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.users_single_layout, parent, false);
return new FilmsViewHolder(mView);
}
};
mFilmsList.setAdapter(adapter);
}
@Override
protected void onStart() {
super.onStart();
adapter.startListening();
}
@Override
protected void onStop() {
super.onStop();
adapter.stopListening();
}
}
布局文件活动\u films.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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="wrap_content"
android:orientation="vertical"
tools:context=".FilmsActivity">
<androidx.recyclerview.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="16dp"
android:id="@+id/films_list" />
</LinearLayout>
com.google.firebase.database.DatabaseException:转换失败
java.lang.Long类型的值转换为字符串
首先,它应该是一个InvocationTargetException
[根据您的数据库结构,]当您尝试在模型中将长
转换为字符串时。尝试更新您的模型,如下所示:
public class Films {
public String name;
public int year;
....
}
然后,您应该将LayoutManager
设置为您的RecyclerView
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
mFilmsList.setLayoutManager(linearLayoutManager);
更新:在使用String.valueOf将int
设置为TextView之前,您必须更新您的onBindViewHolder
以将int
转换为String
@Override
protected void onBindViewHolder(FilmsViewHolder filmsViewHolder, int i, Films films) {
filmsViewHolder.mFilmName.setText(films.getName());
filmsViewHolder.mFilmYear.setText(String.valueOf(films.getYear()));
}
我认为当您从Firebase查询中得到响应时,通常会出现延迟。这可能就是正在发生的事情。初始化适配器时,“选项”列表仍然为空
您很可能需要使用线程同步来完成此操作。如果在onCreateViewHolder
和onBindViewHolder
中设置断点并在调试器中运行代码,它到达那些断点了吗?你为你的recyclerview设置了xml布局管理器了吗?@BlueJones我已经在帖子中添加了布局文件,现在请检查一下once@FrankvanPuffelen不,我还没有学会使用调试器,所以我一点也不知道。是的,你的回收视图中缺少布局管理器,可以添加xmlapp:layoutManager=“androidx.recyclerview.widget.LinearLayoutManager”
或按Md.Asaduzzaman在下面所述的编程方式。我做了如您所说的更改,现在正在抛出错误,应用程序正在崩溃。这是我收到的错误E/AndroidRuntime:FATAL EXCEPTION:main Process:com.dipeshpatil.in,PID:1880 android.content.res.Resources$NotFoundException:String resource ID#0x7d2位于android.content.res.Resources.getText(Resources.java:363)位于android.widget.TextView.setText(TextView.java:6484)位于com.dipeshpatil.in.FilmsActivity$1.onBindViewHolder(FilmsActivity.java:46)在com.dipeshpatil.in.FilmsActivity$1.onBindViewHolder(FilmsActivity.java:41)
使用String.valueOf(films.getYear())
insideonBindViewHolder
谢谢你,它终于成功了!它需要一个布局管理器FirebaseRecyclerAdapter
负责异步加载,并在数据可用/更改时调用notifyDataSetChanged
。哦,好的,谢谢您的澄清。我的印象是你必须自己处理!