我正在尝试将我的Firestore数据放入Android的recyclerview中。该应用程序没有错误，但是没有数据显示。
public class Diseaselist extends AppCompatActivity {
private TextView textView;
private FirebaseFirestore mDatabaseRef;
private Query mChartsQuery;
private RecyclerView mRecycler;
private FirebaseAuth mAuth;
private FirestoreRecyclerAdapter<Upload, ProductViewHolder> adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_diseaselist);
RecyclerView recyclerView = findViewById(R.id.goodmeme);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
FirebaseFirestore rootRef = FirebaseFirestore.getInstance();
mAuth = FirebaseAuth.getInstance();
FirebaseUser currentUser = mAuth.getCurrentUser();
String useruid = currentUser.getUid();
Query query = rootRef.collection("users").document(useruid).collection("diagnoses")
.orderBy("disease", Query.Direction.ASCENDING);
FirestoreRecyclerOptions<Upload> options = new FirestoreRecyclerOptions.Builder<Upload>()
.setQuery(query, Upload.class)
.build();
adapter = new FirestoreRecyclerAdapter<Upload, ProductViewHolder>(options) {
@Override
protected void onBindViewHolder(@NonNull ProductViewHolder holder, int position, @NonNull Upload productModel) {
holder.setProductName(productModel.getDisease());
}
@NonNull
@Override
public ProductViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
android.view.View views = LayoutInflater.from(parent.getContext()).inflate(R.layout.activity_diseaselist, parent, false);
return new ProductViewHolder(views);
}
};
recyclerView.setAdapter(adapter);
}
@Override
protected void onStart() {
super.onStart();
adapter.startListening();
}
@Override
protected void onStop() {
super.onStop();
if (adapter != null) {
adapter.stopListening();
}
}
private class ProductViewHolder extends RecyclerView.ViewHolder {
private android.view.View view;
ProductViewHolder(android.view.View itemView) {
super(itemView);
view = itemView;
}
void setProductName(final String productName) {
CardView cview =view.findViewById(R.id.cardview);
textView = view.findViewById(R.id.texty);
textView.setText(productName);
cview.setOnClickListener(new android.view.View.OnClickListener() {
@Override
public void onClick(android.view.View view) {
Toast.makeText(getApplicationContext(), productName, Toast.LENGTH_SHORT).show();
}
});
}
}
布局文件：
<?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="match_parent"
android:padding="16dp"
tools:context=".Diseaselist"
tools:orientation="vertical">
<TextView
android:id="@+id/texty"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="30sp"
android:text="30sp"/>
<android.support.v7.widget.CardView
android:id="@+id/cardview"
android:layout_width="match_parent"
android:layout_height="wrap_content"
>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="16dp">
<ImageView
android:id="@+id/person_photo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginRight="16dp" />
<TextView
android:id="@+id/person_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_toRightOf="@+id/person_photo"
android:textSize="30sp" />
<TextView
android:id="@+id/person_age"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/person_name"
android:layout_toRightOf="@+id/person_photo" />
</RelativeLayout>
</android.support.v7.widget.CardView>
<android.support.v7.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/goodmeme"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
Firestore structure Firestore Structure Screenshot 2
上传课程代码：
package com.Provendor.Provendor;
import android.os.Parcel;
import android.os.Parcelable;
import java.io.Serializable;
import java.util.Calendar;
public class Upload implements Parcelable {
private String mName;
private String mImageUrl;
private String mdisease;
private String mdate;
private float mconfidence;
@Override
public int describeContents() {
return 0;
}
// write your object's data to the passed-in Parcel
@Override
public void writeToParcel(Parcel out, int flags) {
out.writeFloat(mconfidence);
out.writeString(mName);
out.writeString(mImageUrl);
out.writeString(mdisease);
out.writeString(mdate);
}
// this is used to regenerate your object. All Parcelables must have a CREATOR that implements these two methods
public static final Parcelable.Creator<Upload> CREATOR = new Parcelable.Creator<Upload>() {
public Upload createFromParcel(Parcel in) {
return new Upload(in);
}
public Upload[] newArray(int size) {
return new Upload[size];
}
};
// example constructor that takes a Parcel and gives you an object populated with it's values
private Upload(Parcel in) {
mconfidence = in.readInt();
mName = in.readString();
mImageUrl = in.readString();
mdisease = in.readString();
mdate = in.readString();
}
public Upload() {
mName= ""; //empty constructor needed
}
public Upload(String name, String imageUrl, String disease, float confidence) {
if (name.trim().equals("")) {
name = "No Name";
}
mdisease=disease;
mdate=java.text.DateFormat.getDateTimeInstance().format(Calendar.getInstance().getTime());
mName = name;
mImageUrl = imageUrl;
mconfidence=confidence;
}
public String getName() {
return mName;
}
public String getDisease() {
return mdisease;
}
public float getConfidence() {
return mconfidence;
}
public String getDate() {
return mdate;
}
public void setName(String name) {
mName = name;
}
public void setdate() {
mdate=java.text.DateFormat.getDateTimeInstance().format(Calendar.getInstance().getTime());
}
public void setDisease(String disease) {
mdisease = disease;
}
public void setConfidence(float confidence) {
mconfidence = confidence;
}
public String getImageUrl() {
return mImageUrl;
}
public void setImageUrl(String imageUrl) {
mImageUrl = imageUrl;
}
}
我希望输出结果基于Firestore集合生成疾病列表，但是recyclerview保留为空。连接调试时，不会出现任何错误！感谢您查看！
答案 0 :(得分：0)
您没有从数据库中得到任何东西，因为Upload类中的字段名称与数据库中存在的字段名称不同。两者应该匹配。为了解决这个问题，您可以更改Upload类中所有字段的名称，以匹配数据库中存在的属性，或者可以使用批注。因为我看到您正在使用私有字段和公共获取程序，所以应该仅在获取程序的前面使用PropertyName批注，例如getName()获取程序的外观应如下所示：
@PropertyName("name")
public String getName() {
return mName;
}