我正在制作一个android应用程序。我正在使用firebase realtime database.this我的json文件。
{
"Data" : {
"UyhzVqsz1BVFKoePa2NEmlPFu382" : {
"Budget_Income" : {
"Bonus" : {
"stData1" : "Bonus",
"stData2" : "Extra",
"stData3" : "Income",
"stData4" : "5000"
},
"Salary" : {
"stData1" : "Salary",
"stData2" : "March",
"stData3" : "Income",
"stData4" : "10000"
}
},
"Entry_Income" : {
"Salary" : {
"-MYkkCYsdhi93FC0VlNl" : {
"stData1" : "Salary",
"stData2" : "21 Apr 2021",
"stData3" : "March",
"stData4" : "5000"
},
"-MYkkSo_Z6GMx1q3y9p6" : {
"stData1" : "Salary",
"stData2" : "21 Apr 2021",
"stData3" : "New",
"stData4" : "2000"
}
},
"bbbb" : {
"-MYk3lQuK4X6zcIZtHRD" : {
"stData1" : "bbbb",
"stData2" : "20 Apr 2021",
"stData3" : "ddd",
"stData4" : "500"
}
}
}
}
}
}现在，我正在尝试以回收器视图获取数据。这是我正在使用的代码。
myRef = myfire.getReference().child("Data").child(strUID).child("Budget_Income");
//-------------------------------
//------------------------------------------
Toast.makeText(MainActivity.this, "Please Wait a While !", Toast.LENGTH_LONG).show();
//-------------------------
options1 = new FirebaseRecyclerOptions.Builder<category>()
.setQuery(myRef, category.class)
.build();
final FirebaseRecyclerAdapter<category, holder1> adapter = new FirebaseRecyclerAdapter<category, holder1>(options1) {
@SuppressLint("SetTextI18n")
@Override
protected void onBindViewHolder(@NotNull final holder1 holder, final int i, @NotNull final category passage) {
final String title = getRef(i).getKey();
category=title;
assert title != null;
myRef = myfire.getReference().child("Data").child(strUID).child("Budget_Income");
myRef.child(title).addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
if (dataSnapshot.getValue() == null) {
Toast.makeText(getApplicationContext(), "Data Not Available", Toast.LENGTH_LONG).show();
} else {
final String stData1 = (Objects.requireNonNull(dataSnapshot.child("stData1").getValue())).toString();
final String stData2 = (Objects.requireNonNull(dataSnapshot.child("stData2").getValue())).toString();
final String stData3 = (Objects.requireNonNull(dataSnapshot.child("stData3").getValue())).toString();
final String stData4 = (Objects.requireNonNull(dataSnapshot.child("stData4").getValue())).toString();
category basic = new category(stData1, stData2, stData3, stData4);
holder.tvOne.setText(stData1);
holder.tvTwo.setText(stData4);
}
}
@Override
public void onCancelled(@NonNull DatabaseError error) {
throw error.toException(); // never ignore errors
}
});
myRef = myfire.getReference().child("Data").child(strUID).child("Entry_Income").child(title);
String uid = myRef.push().getKey();
assert uid != null;
myRef.child(uid).addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
if (dataSnapshot.getValue() == null) {
Toast.makeText(getApplicationContext(), "Data Not Available", Toast.LENGTH_LONG).show();
} else {
final String stData1 = (Objects.requireNonNull(dataSnapshot.child("stData1").getValue())).toString();
final String stData2 = (Objects.requireNonNull(dataSnapshot.child("stData2").getValue())).toString();
final String stData3 = (Objects.requireNonNull(dataSnapshot.child("stData3").getValue())).toString();
final String stData4 = (Objects.requireNonNull(dataSnapshot.child("stData4").getValue())).toString();
category basic = new category(stData1, stData2, stData3, stData4);
holder.tvThree.setText(stData3);
holder.tvFour.setText(stData4);
}
}
@Override
public void onCancelled(@NonNull DatabaseError error) {
throw error.toException(); // never ignore errors
}
});
}
@NonNull
@Override
public holder1 onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.item1, parent, false);
return new holder1(v);
}
};
userlist.setAdapter(adapter);
adapter.startListening();
}
}我得到了tvone和tvo2的值。但是tv3和tv4没有显示数据。
如果我尝试用实际自动生成的id替换字符串uid，例如“-mykkcyshi93fc0vlnl”，它工作得很好，但只有一个孩子。我需要在“收入”项下的所有节点，如“工资”和“奖金”，以及它们的子节点，如“-mykkcyshi93fc0vlnl”和“-mykkso_z6gmx1q3y9p6”等。我已经厌倦了解决这个问题的尝试。我已经尽力了知识问题存在于以下几个方面lines:-
myfire.getReference().child("Data").child(strUID).child("Entry_Income").child(title);
String uid = myRef.push().getKey();
assert uid != null;
myRef.child(uid).addValueEventListener(new ValueEventListener() {请转寄我的代码和修改。
类别类
公共类类别{
private String stData1;
private String stData2;
private String stData3;
private String stData4;
public category() {
}
public category(String stData1, String stData2, String stData3, String stData4) {
this.stData1 = stData1;
this.stData2 = stData2;
this.stData3 = stData3;
this.stData4 = stData4;
}
public String getStData1() {
return stData1;
}
public void setStData1(String stData1) {
this.stData1 = stData1;
}
public String getStData2() {
return stData2;
}
public void setStData2(String stData2) {
this.stData2 = stData2;
}
public String getStData3() {
return stData3;
}
public void setStData3(String stData3) {
this.stData3 = stData3;
}
public String getStData4() {
return stData4;
}
public void setStData4(String stData4) {
this.stData4 = stData4;
}}
* The Code that worked with an error**
myRef = myfire.getReference().child("Data").child(strUID).child("Entry_Income").child(title);
myRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot data : dataSnapshot.getChildren()) {
String value = data.child("stData4").getValue(String.class);
}
holder.tvThree.setText(value);
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
throw databaseError.toException(); // never ignore errors
}
});错误是什么？
当我向下滚动“回收器”视图时，“回收器”视图的后面的项目没有数据。
暂无答案！
目前还没有任何答案，快来回答吧！