获取Firebase Android的平均评级
我正在关注如何获得平均收视率,但我收到了一条错误消息:获取Firebase Android的平均评级,android,firebase-realtime-database,average,rating,Android,Firebase Realtime Database,Average,Rating,我正在关注如何获得平均收视率,但我收到了一条错误消息: E/AndroidRuntime: FATAL EXCEPTION: main Process: com.fixitph.client, PID: 25744 com.google.firebase.database.DatabaseException: Failed to convert a value of type java.util.HashMap to double at com.google.android.gms.intern
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.fixitph.client, PID: 25744
com.google.firebase.database.DatabaseException: Failed to convert a value of type java.util.HashMap to double
at com.google.android.gms.internal.zzelw.zzbz(Unknown Source)
at com.google.android.gms.internal.zzelw.zzb(Unknown Source)
at com.google.android.gms.internal.zzelw.zza(Unknown Source)
at com.google.firebase.database.DataSnapshot.getValue(Unknown Source)
at com.fixitph.client.ReceiptActivity$2.onDataChange(ReceiptActivity.java:85)
这是我的密码:
ratingBar.setOnRatingChangeListener(new MaterialRatingBar.OnRatingChangeListener() {
@Override
public void onRatingChanged(MaterialRatingBar ratingBar, float rating) {
final DatabaseReference dbRef = FirebaseDatabase.getInstance().getReference(Common.worker_rating_table)
.child(Common.workerId).child(uid).child("Rating");
double dbRating = rating;
dbRef.setValue(dbRating);
}
});
public void submitRating(View view) {
final DatabaseReference dbRef = FirebaseDatabase.getInstance().getReference(Common.worker_rating_table)
.child(Common.workerId);
dbRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
double total = 0.0;
double count = 0.0;
double average = 0.0;
for(DataSnapshot ds: dataSnapshot.getChildren()) {
double rating = dataSnapshot.getValue(Double.class);
total = total + rating;
count = count + 1;
average = total / count;
}
final DatabaseReference newRef = dbRef.child(uid);
newRef.child("averageRating").setValue(average);
}
@Override
public void onCancelled(DatabaseError databaseError) {
throw databaseError.toException();
}
});
}
我的数据库如下所示
这一行是指ReceiptActivity.java:85
double rating = dataSnapshot.getValue(Double.class);
我想知道这是否是因为我试图找到一个双精度,但是评级中有一个整数,如果是这样的话,我如何调整它来获得评级的平均值?请帮忙。谢谢!:)
您需要从评级
子级中获取值,并将其解析为双精度
ratingBar.setOnRatingChangeListener(new MaterialRatingBar.OnRatingChangeListener() {
@Override
public void onRatingChanged(MaterialRatingBar ratingBar, float rating) {
final DatabaseReference dbRef = FirebaseDatabase.getInstance().getReference(Common.worker_rating_table)
.child(Common.workerId).child(Common.user_clients_table).child(uid).child("rating");
double intRating = rating;
dbRef.setValue(intRating);
}
});
settingInformation();
}
public void submitRating(View view) {
try {
final DatabaseReference db = FirebaseDatabase.getInstance().getReference();
final DatabaseReference dbRef = db.child(Common.worker_rating_table).child(Common.workerId).child(Common.user_clients_table);
dbRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
double total = 0.0;
double count = 0.0;
double average = 0.0;
for(DataSnapshot ds: dataSnapshot.getChildren()) {
double rating = Double.parseDouble(ds.child("rating").getValue().toString());
total = total + rating;
count = count + 1;
average = total / count;
}
final DatabaseReference newRef = db.child(Common.worker_rating_table).child(Common.workerId).child("AverageRating");
newRef.child("current").setValue(average);
}
@Override
public void onCancelled(DatabaseError databaseError) {
throw databaseError.toException();
}
});
} catch (Exception e) {
Toast.makeText(ReceiptActivity.this, "" + e, Toast.LENGTH_SHORT).show();
}
}
我必须添加节点来分离当前的平均值和客户端的评级,这样它才能工作。以下是数据库的外观:
谢谢你的想法,我只需要循环一下
double rating=double.parseDouble(ds.child(“rating”).getValue().toString())代码>并且我能够得到我需要的输出。我会用我最终得到的代码更新我的问题。
ratingBar.setOnRatingChangeListener(new MaterialRatingBar.OnRatingChangeListener() {
@Override
public void onRatingChanged(MaterialRatingBar ratingBar, float rating) {
final DatabaseReference dbRef = FirebaseDatabase.getInstance().getReference(Common.worker_rating_table)
.child(Common.workerId).child(Common.user_clients_table).child(uid).child("rating");
double intRating = rating;
dbRef.setValue(intRating);
}
});
settingInformation();
}
public void submitRating(View view) {
try {
final DatabaseReference db = FirebaseDatabase.getInstance().getReference();
final DatabaseReference dbRef = db.child(Common.worker_rating_table).child(Common.workerId).child(Common.user_clients_table);
dbRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
double total = 0.0;
double count = 0.0;
double average = 0.0;
for(DataSnapshot ds: dataSnapshot.getChildren()) {
double rating = Double.parseDouble(ds.child("rating").getValue().toString());
total = total + rating;
count = count + 1;
average = total / count;
}
final DatabaseReference newRef = db.child(Common.worker_rating_table).child(Common.workerId).child("AverageRating");
newRef.child("current").setValue(average);
}
@Override
public void onCancelled(DatabaseError databaseError) {
throw databaseError.toException();
}
});
} catch (Exception e) {
Toast.makeText(ReceiptActivity.this, "" + e, Toast.LENGTH_SHORT).show();
}
}