我正在使用Firebase创建一个应用程序，用户可以在其中注册一个课程，然后查看它们。我将相同的回收站适配器和对象用于显示类和显示用户类在其uid下的用户的活动。当我运行该应用程序时，这些类会显示我已经输入到Firebase中，但是显示用户类的活动会显示一个空白的cardview（使用相同的代码）。错误是：`
No setter/field for room_number2 found on class com.samuelford48gmail.thsconnect.Class_model
No setter/field for date_clasname2 found on class com.samuelford48gmail.thsconnect.Class_model
No setter/field for teacher2 found on class com.samuelford48gmail.thsconnect.Class_model
我显示用户类的片段的代码：
public class home_fragment extends Fragment implements View.OnClickListener {
private Button button;
//DatabaseReference dref;
//ListView listview2;
//ArrayList<String> list=new ArrayList<>();
private FirebaseDatabase database;
private DatabaseReference myRef;
private List<Listdata> list;
private RecyclerView recyclerview;
public home_fragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.home_fragment, container, false);
//FirebaseUser fbUser = FirebaseAuth.getInstance().getCurrentUser();
//if(fbUser == null) { Intent intent = new Intent(getContext(), LoginActivity.class);
// startActivity(intent);}
button = (Button) view.findViewById(R.id.button);
button.setOnClickListener(this);
recyclerview = (RecyclerView) view.findViewById(R.id.rview);
database = FirebaseDatabase.getInstance();
myRef = database.getReference("Users")
.child(FirebaseAuth.getInstance().getCurrentUser().getUid()).child("Classes");
myRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
list = new ArrayList<>();
// StringBuffer stringbuffer = new StringBuffer();
for (DataSnapshot dataSnapshot1 : dataSnapshot.getChildren()) {
Class_model new_class = dataSnapshot1.getValue(Class_model.class);
String nameofclass = new_class.getDate_clasname();
String teacherofclass = new_class.getTeacher();
String roomnumberofclass = new_class.getRoom_number();
String class_key = new_class.getUid();
Listdata listdata = new Listdata(nameofclass, teacherofclass, roomnumberofclass, class_key);
//String name = userdetails.getName();
//String email = userdetails.getEmail();
//String address = userdetails.getAddress();
listdata.setDate_class(nameofclass);
listdata.setTeacher(teacherofclass);
listdata.setRnumber(roomnumberofclass);
list.add(listdata);
// Toast.makeText(MainActivity.this,""+name,Toast.LENGTH_LONG).show();
}
RecyclerviewAdapter2 recycler = new RecyclerviewAdapter2(list);
RecyclerView.LayoutManager layoutmanager = new LinearLayoutManager(getContext());
recyclerview.setLayoutManager(layoutmanager);
recyclerview.setItemAnimator(new DefaultItemAnimator());
recyclerview.setAdapter(recycler);
}
@Override
public void onCancelled(DatabaseError error) {
AlertDialog alertDialog = new AlertDialog.Builder(getContext()).create();
alertDialog.setTitle("Error");
alertDialog.setMessage("Check your connection! If, problem persists please email svhsdev@vigoschools.org!");
alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
alertDialog.show();
// Failed to read value
// Log.w(TAG, "Failed to read value.",
error.toException());
}
});
return view;
}
@Override
public void onClick(View view) {
signout();
//startActivity(new Intent(home_fragment.this,
LoginActivity.class));
}
public void signout(){
FirebaseAuth.getInstance().signOut();
Intent intent = new Intent(getContext(), LoginActivity.class);
startActivity(intent);
}
}
这是我的Recycler Adapter类的代码：
public class RecyclerviewAdapter2 extends RecyclerView.Adapter<RecyclerviewAdapter2.MyHolder>{
List<Listdata> listdata;
public RecyclerviewAdapter2(List<Listdata> listdata) {
this.listdata = listdata;
}
@Override
public RecyclerviewAdapter2.MyHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.cardview_class_model,parent,false);
RecyclerviewAdapter2.MyHolder myHolder = new RecyclerviewAdapter2.MyHolder(view);
return myHolder;
}
public void onBindViewHolder(RecyclerviewAdapter2.MyHolder holder, final int position) {
final Listdata data = listdata.get(position);
holder.vdate_class.setText(data.getDate_class());
holder.vteacher.setText(data.getTeacher());
holder.vrnumber.setText(data.getRnumber());
//System.out.println(data.getDate_class2());
holder.itemView.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick( final View view) {
Context context = view.getContext();
Intent intent = new Intent(context, test_for_science_add_class.class);
intent.putExtra("date_class", listdata.get(position).getDate_class());
intent.putExtra("teacher", listdata.get(position).getTeacher());
intent.putExtra("room_number", listdata.get(position).getRnumber());
intent.putExtra("post_key", listdata.get(position).getUid());
context.startActivity(intent);
}
});
}
@Override
public int getItemCount() {
return listdata.size();
}
class MyHolder extends RecyclerView.ViewHolder{
TextView vdate_class , vteacher,vrnumber;
public MyHolder(View itemView) {
super(itemView);
vdate_class = (TextView) itemView.findViewById(R.id.date_class_name);
vteacher = (TextView) itemView.findViewById(R.id.teacher);
vrnumber = (TextView) itemView.findViewById(R.id.room_number);
}
}
}
这是我的Class_model代码：
public class Class_model {
//String subject;
String date_clasname;
String teacher;
String room_number;
String uid;
public Class_model(){};
public Class_model(String date_classname, String teacher, String room_number, String uid){
this.date_clasname = date_classname;
this.teacher = teacher;
this.room_number = room_number;
this.uid = uid;
}
public String getDate_clasname() {
return date_clasname;
}
public void setDate_clasname(String date_clasname) {
this.date_clasname = date_clasname;
}
public String getTeacher() {
return teacher;
}
public void setTeacher(String teacher) {
this.teacher = teacher;
}
public String getRoom_number() {
return room_number;
}
public void setRoom_number(String room_number) {
this.room_number = room_number;
}
public String getUid() {
return uid;
}
public void setUid(String uid) {
this.uid = uid;
}
}
这是我的Listdata类的代码：
public class Listdata {
String date_class;
String teacher;
String rnumber;
String uid;
public Listdata(String date_class, String teacher, String rnumber, String uid) {
this.date_class = date_class;
this.teacher = teacher;
this.rnumber = rnumber;
this.uid = uid;
}
public String getDate_class() {
return date_class;
}
public void setDate_class(String date_class) {
this.date_class = date_class;
}
public String getTeacher() {
return teacher;
}
public void setTeacher(String teacher) {
this.teacher = teacher;
}
public String getRnumber() {
return rnumber;
}
public void setRnumber(String rnumber) {
this.rnumber = rnumber;
}
public String getUid() {
return uid;
}
public void setUid(String uid) {
this.uid = uid;
}
}
我的Firebase结构：
"Technology" : {
"-LgxmDqmlPZnCOEyjBww" : {
"date_clasname" : "technology",
"room_number" : "d",
"teacher" : "f"
}
},
"Users" : {
"NnJlSVeqGXhJ2Nab2bhjr0HIpku2" : {
"Classes" : {
"-LhM7iyYhmwvtDvtLE-Z" : {
"date_clasname2" : "technology",
"room_number2" : "d",
"teacher2" : "f"
},
"-LhM7k0uI_eY31nQnnro" : {
"date_clasname2" : "other",
"room_number2" : "d",
"teacher2" : "f"
},
"-LhM87eT7kv7KL1JHryM" : {
"date_clasname2" : "March 5",
"room_number2" : "101",
"teacher2" : "pence"
}
},
"email" : "samuelford48@gmail.com",
"grade" : "12",
"name" : "Samuel Ford"
},
这是我的代码，当用户单击“回收者”视图项之一时发生的活动：
public class test_for_science_add_class extends AppCompatActivity {
private Button add_class;
private FirebaseDatabase database;
private DatabaseReference myRef;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test_for_science_addd_class);
final String date_class2 = getIntent().getStringExtra("date_class");
final String teacher = getIntent().getStringExtra("teacher");
final String room_number = getIntent().getStringExtra("room_number");
final String post_key = getIntent().getStringExtra("post_key");
database = FirebaseDatabase.getInstance();
myRef = database.getReference("Users").child(FirebaseAuth.getInstance().getCurrentUser().getUid()).child("Classes");
//String name = getIntent().getExtra("date_class");
//String city = getIntent().getExtra("City");
//System.out.println(value);
TextView display_class_name = (TextView) findViewById(R.id.date_tv2);
display_class_name.setText(date_class2);
TextView display_teacher = (TextView) findViewById(R.id.teacher_tv2);
display_teacher.setText(teacher);
TextView display_room_number = (TextView) findViewById(R.id.rn_tv2);
display_room_number.setText(room_number);
add_class = (Button) findViewById(R.id.add_class_2);
add_class.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Class_model_without_uid new_class_to_user_uid = new Class_model_without_uid(date_class2, teacher, room_number);
myRef.push().setValue(new_class_to_user_uid);
Toast.makeText(getApplicationContext(), "test", Toast.LENGTH_SHORT).show();
}
});
}
}
答案 0 :(得分：0)
在处理对回收站项目的点击的活动中，当我推送到Firebase时，我调用了错误的对象类。
错误代码：
NavigationView {
Text("Hello world")
.navigationBarTitle(Text("Title"))
.navigationBarItems(trailing:
PresentationButton(destination: TestView()) {
Text("Next")
}
)
}
正确的代码：
Class_model_without_uid new_class_to_user_uid = new Class_model_without_uid(date_class2, teacher, room_number);
myRef.push().setValue(new_class_to_user_uid);