此时我在同一页面上有两个 RecyclerView,分别是早餐和午餐 RecyclerView,但我面临以下错误:无法将 java.lang.String 类型的对象转换为 com.example 类型
它突出显示了这一行
userRecordslist.add(ds.getValue(UserRecordsModel.class));
我尝试过多种方法。
但是当我使用这段代码时,来自不同记录的数据显示在早餐RecyclerView中
myRef = FirebaseDatabase.getInstance().
getReference("UsersRecords").child(FirebaseAuth.getInstance().getCurrentUser().getUid())
.child(date_record);
这些是我的 Firebase 和应用程序的屏幕截图。您可以看到来自不同记录的数据都显示在同一个 RecyclerView 上。
后来我尝试使用这个"new"代码进行数据库引用,据称从 Firebase 检索的数据未显示在早餐回收器 View 上,并且我得到了无法转换 java 类型的对象.lang.String 类型错误
myRef = FirebaseDatabase.getInstance().
getReference("UsersRecords").child(FirebaseAuth.getInstance().getCurrentUser().getUid())
.child(date_record).child("BreakfastRecord");
我想获取数据并将其显示在“假设”RecyclerView 中。请大家帮忙。
我的 PlanMeal Activity 的代码:
//BUTTON
Button backBtn;
Button addMealBreakBtn;
Button addMealLunchBtn;
Button addMealDinnerBtn;
//DATABASE
FirebaseAuth mAuth;
FirebaseUser currentUser;
DatabaseReference userRecordRef, myRef,requiredCalorieRef, mylunchRef;
//TEXT VIEW
TextView userRequiredCalorie;
ArrayList<UserRecordsModel> userRecordslist;
RecyclerView recyclerView, recyclerViewlunch;
private RecyclerView.Adapter userRecordHolder;
//DATE
String date_record ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_plan_meal_user);
date_record = new SimpleDateFormat("yyMMdd", Locale.getDefault()).format(new Date());
//create a date string.
String date_n = new SimpleDateFormat("MMM dd, yyyy", Locale.getDefault()).format(new Date());
//get hold of textview.
TextView date = (TextView) findViewById(R.id.datePlanMeal);
//set it as current date.
date.setText(date_n);
//INI VIEWS
userRequiredCalorie= (TextView) findViewById(R.id.outputPlanMealCalorie);
//FIREBASE AUTH
mAuth = FirebaseAuth.getInstance();
currentUser=mAuth.getCurrentUser();
//DATABASE REFERENCE
myRef = FirebaseDatabase.getInstance().
getReference("UsersRecords").child(FirebaseAuth.getInstance().getCurrentUser().getUid())
.child(date_record);
/*mylunchRef=FirebaseDatabase.getInstance().
getReference("UsersRecords").child(FirebaseAuth.getInstance().getCurrentUser().getUid())
.child(date_record).child("LunchRecord");*/
//myRef = FirebaseDatabase.getInstance().getReference("UsersRecords").child(FirebaseAuth.getInstance().getCurrentUser().getUid());
//mylunchRef = FirebaseDatabase.getInstance().getReference("UsersRecords").child(FirebaseAuth.getInstance().getCurrentUser().getUid());
//RECYCLER VIEW
//*********BREAKFAST******************************************//
recyclerView = findViewById(R.id.userRecordRecylerView);
LinearLayoutManager manager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(manager);
recyclerView.setHasFixedSize(true);
//ADAPTER
userRecordslist = new ArrayList<>();
userRecordHolder = new UserRecordsHolder(userRecordslist);
recyclerView.setAdapter(userRecordHolder);
//*********LUNCH******************************************//
recyclerViewlunch = findViewById(R.id.userRecordRecylerViewLunch);
LinearLayoutManager manager1 = new LinearLayoutManager(this);
recyclerViewlunch.setLayoutManager(manager1);
recyclerViewlunch.setHasFixedSize(true);
//ADAPTER
userRecordslist = new ArrayList<>();
userRecordHolder = new UserRecordsHolder(userRecordslist);
recyclerViewlunch.setAdapter(userRecordHolder);
//BUTTON
addMealBreakBtn = (Button) findViewById(R.id.addMealBreakBtn);
backBtn = (Button)findViewById(R.id.backBtnPlan) ;
//**********************DATABASE REFERENCE FOR USER REQUIRED CALORIE***************************//
requiredCalorieRef = FirebaseDatabase.getInstance().getReference("Users").child(FirebaseAuth.getInstance().getCurrentUser().getUid());
requiredCalorieRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
String userCalorieSuggestion = String.valueOf((dataSnapshot.child("daily calorie").getValue()));
userRequiredCalorie.setText((userCalorieSuggestion +"kcal"));
/*String userCalorieSuggestion = Double.toString((Double) dataSnapshot.child("daily calorie").getValue());
showDailyCalorie.setText(("Daily Calorie Suggestion: " + userCalorieSuggestion +"kcal"));*/
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
//BACK BUTTON*************************************************
backBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent signIn = new Intent(PlanMealUser.this,HomepageUser.class);
startActivity(signIn);
}
});
//ADD MEAL BUTTONS**********************************************
addMealBreakBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent breakfast = new Intent(PlanMealUser.this,ViewProduct.class);
startActivity(breakfast);
}
});
addMealLunchBtn = (Button) findViewById(R.id.addMealLunchBtn);
addMealLunchBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent signIn = new Intent(PlanMealUser.this,ViewProduct_Lunch.class);
startActivity(signIn);
}
});
addMealDinnerBtn = (Button) findViewById(R.id.addMealDinnerBtn);
addMealDinnerBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent signIn = new Intent(PlanMealUser.this,ViewProduct.class);
startActivity(signIn);
}
});
}
@Override
protected void onStart() {
super.onStart();
if (myRef != null) {
myRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
if (dataSnapshot.exists()) {
userRecordslist = new ArrayList<>();
for (DataSnapshot ds : dataSnapshot.getChildren()) {
userRecordslist.add(ds.getValue(UserRecordsModel.class));
}
UserRecordsHolder userRecordHolder = new UserRecordsHolder(userRecordslist);
recyclerView.setAdapter(userRecordHolder);
}
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
Toast.makeText(PlanMealUser.this, databaseError.getMessage(),
Toast.LENGTH_SHORT).show();
}
});
}
}
}
这是我的模型:
package com.example.buddymealplanneruser.Child.UserRecords;
public class UserRecordsModel {
private String foodName;
private String foodCalorie;
//constructor
public UserRecordsModel (String foodName,
String foodCalorie
)
{
this.foodName = foodName;
this.foodCalorie = foodCalorie;
}
public UserRecordsModel(){
}
//Getter and Setter
public String getFoodName() {
return foodName;
}
public void setFoodName(String foodName) {
this.foodName = foodName;
}
public String getFoodCalorie() {
return foodCalorie;
}
public void setFoodCalorie(String foodCalorie) {
this.foodCalorie = foodCalorie;
}
}
这是我的适配器
public class UserRecordsHolder extends RecyclerView.Adapter<UserRecordsHolder.MyURHolder> {
Context context;
ArrayList<UserRecordsModel> userRecordslist;
public UserRecordsHolder (ArrayList<UserRecordsModel> userRecordslist)
{
this.userRecordslist=userRecordslist;
}
@NonNull
@Override
public MyURHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.row_user_records, viewGroup,false);
return new MyURHolder(view);
}
@Override
public void onBindViewHolder(@NonNull MyURHolder myURHolder, int i) {
myURHolder.foodName.setText(userRecordslist.get(i).getFoodName());
myURHolder.foodCalorie.setText(userRecordslist.get(i).getFoodCalorie());
}
@Override
public int getItemCount()
{
return userRecordslist.size();
}
class MyURHolder extends RecyclerView.ViewHolder
{
TextView foodName, foodCalorie;
public MyURHolder (@NonNull View itemView){
super(itemView);
foodName = itemView.findViewById(R.id.userRecordsFName);
foodCalorie = itemView.findViewById(R.id.userRecordsKcal);
}
}
}
希望有人能帮忙。
最佳答案
您需要在 BreakfastRecord 或 LunchRecord 下面再增加一个级别:
UserRecords
UID
Date
BreakfastRecord
1
foodCalorie
foodName
2
foodCalorie
foodName
3
foodCalorie
foodName
关于java - 无法将 java.lang.String 类型的对象转换为类型(Firebase、RecyclerView),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/58277851/