我要构建的应用程序必须具有一个微调器，该微调器可以动态更改recyclerView的项目。 此刻，当更改微调器项目时，什么都没有发生，但是当我打开另一个活动然后又回来时，数据也随之更改 更改微调框选择的项目时如何更改数据。 下面是我的代码
package com.example.tutorscape;
import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
import com.firebase.ui.firestore.FirestoreRecyclerAdapter;
import com.firebase.ui.firestore.FirestoreRecyclerOptions;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.firestore.FirebaseFirestore;
import com.google.firebase.firestore.Query;
import com.squareup.picasso.Picasso;
import jp.wasabeef.picasso.transformations.CropCircleTransformation;
public class TutorListActivity extends BaseActivity {
private SqliteDatabase mDatabase;
boolean isFragmentLoaded;
Fragment menuFragment;
TextView title;
ImageView menuButton;
private static final String TAG = "SignedInActivity";
//Firebase
private FirebaseAuth.AuthStateListener mAuthListener;
// widgets and UI References
private RecyclerView mFirebaseList;
private FirebaseFirestore firebaseFirestore;
private FirestoreRecyclerAdapter adapter;
@Override
protected void onResume() {
super.onResume();
checkAuthenticationState();
}
private void checkAuthenticationState(){
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
if(user == null){
Intent intent = new Intent(TutorListActivity.this, LoginStudent.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
finish();
}else{
Log.d(TAG, "checkAuthenticationState: user is authenticated.");
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
initAddlayout(R.layout.activity_tutor_list);
Spinner spinner =(Spinner)findViewById(R.id.spinner);
firebaseFirestore = FirebaseFirestore.getInstance();
mFirebaseList = findViewById(R.id.recyclerView);
mDatabase = new SqliteDatabase(this);
title = (TextView) findViewById(R.id.title_top);
menuButton = (ImageView) findViewById(R.id.menu_icon);
title.setText("Menu Activity");
menuButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (!isFragmentLoaded) {
loadFragment();
title.setText("Profile");
} else {
if (menuFragment != null) {
if (menuFragment.isAdded()) {
hideFragment();
}
}
}
}
});
Query query = firebaseFirestore.collection("Admin");
FirestoreRecyclerOptions<Model> options = new FirestoreRecyclerOptions.Builder<Model>()
.setQuery(query, Model.class)
.build();
adapter = new FirestoreRecyclerAdapter<Model, MyViewHolder>(options) {
@NonNull
@Override
public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);
return new MyViewHolder(view);
}
@Override
protected void onBindViewHolder(@NonNull MyViewHolder holder, int position, @NonNull Model model) {
holder.list_name.setText(model.getName());
holder.list_title.setText(model.getTitle());
holder.list_imageText.setText(model.getImage());
holder.weeklyRate.setText(model.getWeeklyRate());
holder.subject.setText(model.getSubject());
holder.phone.setText(model.getPhone());
holder.trial.setText(model.getTrial());
Picasso.get()
.load(model.getImage())
// .centerCrop()
// .placeholder(R.drawable.account)
// .resize(w, h)
.transform(new CropCircleTransformation())
.into(holder.imageView);
}
};
mFirebaseList.setHasFixedSize(true);
mFirebaseList.setLayoutManager(new LinearLayoutManager(TutorListActivity.this));
mFirebaseList.setAdapter(adapter);
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
if(position==0){
Query query = firebaseFirestore.collection("Admin");
FirestoreRecyclerOptions<Model> options = new FirestoreRecyclerOptions.Builder<Model>()
.setQuery(query, Model.class)
.build();
adapter = new FirestoreRecyclerAdapter<Model, MyViewHolder>(options) {
@NonNull
@Override
public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);
return new MyViewHolder(view);
}
@Override
protected void onBindViewHolder(@NonNull MyViewHolder holder, int position, @NonNull Model model) {
holder.list_name.setText(model.getName());
holder.list_title.setText(model.getTitle());
holder.list_imageText.setText(model.getImage());
holder.weeklyRate.setText(model.getWeeklyRate());
holder.subject.setText(model.getSubject());
holder.phone.setText(model.getPhone());
holder.trial.setText(model.getTrial());
Picasso.get()
.load(model.getImage())
// .centerCrop()
// .placeholder(R.drawable.account)
// .resize(w, h)
.transform(new CropCircleTransformation())
.into(holder.imageView);
}
};
mFirebaseList.setHasFixedSize(true);
mFirebaseList.setLayoutManager(new LinearLayoutManager(TutorListActivity.this));
mFirebaseList.setAdapter(adapter);
}else if(position==1){
Query query = firebaseFirestore.collection("one");
FirestoreRecyclerOptions<Model> options = new FirestoreRecyclerOptions.Builder<Model>()
.setQuery(query, Model.class)
.build();
adapter = new FirestoreRecyclerAdapter<Model, MyViewHolder>(options) {
@NonNull
@Override
public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);
return new MyViewHolder(view);
}
@Override
protected void onBindViewHolder(@NonNull MyViewHolder holder, int position, @NonNull Model model) {
holder.list_name.setText(model.getName());
holder.list_title.setText(model.getTitle());
holder.list_imageText.setText(model.getImage());
holder.weeklyRate.setText(model.getWeeklyRate());
holder.subject.setText(model.getSubject());
holder.phone.setText(model.getPhone());
holder.trial.setText(model.getTrial());
Picasso.get()
.load(model.getImage())
// .centerCrop()
// .placeholder(R.drawable.account)
// .resize(w, h)
.transform(new CropCircleTransformation())
.into(holder.imageView);
}
};
mFirebaseList.setHasFixedSize(true);
mFirebaseList.setLayoutManager(new LinearLayoutManager(TutorListActivity.this));
mFirebaseList.setAdapter(adapter);
}else if(position==2){
}else if (position==3){
}else if(position==4){
}else if(position==5){
}else if (position==6){
}
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
}
private class MyViewHolder extends RecyclerView.ViewHolder {
private TextView list_name, subject, weeklyRate, trial, phone;
private TextView list_title, list_imageText;
private ImageView imageView;
public MyViewHolder(@NonNull View itemView) {
super(itemView);
subject = itemView.findViewById(R.id.textViewSubject);
weeklyRate = itemView.findViewById(R.id.textViewWeeklyRate);
trial = itemView.findViewById(R.id.textViewTrial);
phone = itemView.findViewById(R.id.textViewPhone);
list_imageText = itemView.findViewById(R.id.phoneTextView);
list_name = itemView.findViewById(R.id.textViewName);
list_title = itemView.findViewById(R.id.textViewTitle);
imageView = itemView.findViewById(R.id.imageView);
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
final String name = list_name.getText().toString();
final String ph_no = subject.getText().toString();
final String title = list_title.getText().toString();
final String sweekly = weeklyRate.getText().toString();
final String strial = trial.getText().toString();
final String image = list_imageText.getText().toString();
final String smsNumber = phone.getText().toString();
Contacts newContact = new Contacts(name, ph_no, title, image, sweekly, strial, smsNumber);
mDatabase.addContacts(newContact);
// String smsNumber = "263774233406"; // E164 format without '+' sign
Intent sendIntent = new Intent(Intent.ACTION_SEND);
sendIntent.setType("text/plain");
sendIntent.putExtra(Intent.EXTRA_TEXT, "Hello Mr Russo.");
sendIntent.putExtra("jid", smsNumber + "@s.whatsapp.net"); //phone number without "+" prefix
sendIntent.setPackage("com.whatsapp");
/*if (sendIntent.resolveActivity(getActivity().getPackageManager()) == null) {
Toast.makeText(this, "Error/n" + e.toString(), Toast.LENGTH_SHORT).show();
return;
}
*/
startActivity(sendIntent);
}
});
}
}
@Override
protected void onStart() {
super.onStart();
adapter.startListening();
}
@Override
protected void onStop() {
super.onStop();
adapter.stopListening();
}
public void hideFragment() {
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.setCustomAnimations(R.anim.slide_down, R.anim.slide_up);
fragmentTransaction.remove(menuFragment);
fragmentTransaction.commit();
menuButton.setImageResource(R.drawable.ic_round_notes);
isFragmentLoaded = false;
title.setText("Main Activity");
}
public void loadFragment() {
FragmentManager fm = getSupportFragmentManager();
menuFragment = fm.findFragmentById(R.id.container);
menuButton.setImageResource(R.drawable.my_up);
if (menuFragment == null) {
menuFragment = new MenuFragment();
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.setCustomAnimations(R.anim.slide_down, R.anim.slide_up);
fragmentTransaction.add(R.id.container, menuFragment);
fragmentTransaction.commit();
}
isFragmentLoaded = true;
}
@Override
public void onBackPressed() {
if (isFragmentLoaded=true){
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.setCustomAnimations(R.anim.slide_down, R.anim.slide_up);
fragmentTransaction.remove(menuFragment);
fragmentTransaction.commit();
menuButton.setImageResource(R.drawable.ic_round_notes);
isFragmentLoaded = false;
title.setText("Main Activity");
}else{
super.onBackPressed();
}
}
public void signOut() {
Log.d(TAG, "signOut: signing out");
FirebaseAuth.getInstance().signOut();
// SharedPreferences.Editor editor = getSharedPreferences(myPrefs, MODE_PRIVATE).edit();
// editor.putBoolean("isStudent", false);
// editor.apply();
Intent intent = new Intent(TutorListActivity.this, WelcomeActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
finish();
}
/*
----------------------------- Firebase setup ---------------------------------
*/
private void setupFirebaseAuth(){
Log.d(TAG, "setupFirebaseAuth: started.");
mAuthListener = new FirebaseAuth.AuthStateListener() {
@Override
public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
FirebaseUser user = firebaseAuth.getCurrentUser();
if (user != null) {
Log.d(TAG, "onAuthStateChanged:signed_in:" + user.getUid());
} else {
Log.d(TAG, "onAuthStateChanged:signed_out");
Intent intent = new Intent(TutorListActivity.this, LoginStudent.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
finish();
}
// ...
}
};
}
}
答案 0 :(得分：0)
如果我正确阅读了代码，则希望适配器在图像加载到此后刷新UI：
Picasso.get()
.load(model.getImage())
// .centerCrop()
// .placeholder(R.drawable.account)
// .resize(w, h)
.transform(new CropCircleTransformation())
.into(holder.imageView);
在这种情况下，您可以pass in a callback to into并在那里打电话给adapter.notifyDataSetChanged。
.into(holder.imageView, new Callback() {
@Override
public void onSuccess() {
adapter.notifyDataSetChanged();
}
@Override
public void onError(java.lang.Exception e) {
Log.e("Image", "Error loading image", e);
}
);
答案 1 :(得分：0)
添加了adapter.startlistening（）;单击每个项目后，它现在可以使用...每个项目如下所示
else if (position==6){
Query query = firebaseFirestore.collection("six");
FirestoreRecyclerOptions<Model> options = new FirestoreRecyclerOptions.Builder<Model>()
.setQuery(query, Model.class)
.build();
adapter = new FirestoreRecyclerAdapter<Model, MyViewHolder>(options) {
@NonNull
@Override
public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);
return new MyViewHolder(view);
}
@Override
protected void onBindViewHolder(@NonNull MyViewHolder holder, int position, @NonNull Model model) {
holder.list_name.setText(model.getName());
holder.list_title.setText(model.getTitle());
holder.list_imageText.setText(model.getImage());
holder.weeklyRate.setText(model.getWeeklyRate());
holder.subject.setText(model.getSubject());
holder.phone.setText(model.getPhone());
holder.trial.setText(model.getTrial());
Picasso.get()
.load(model.getImage())
// .centerCrop()
// .placeholder(R.drawable.account)
// .resize(w, h)
.transform(new CropCircleTransformation())
.into(holder.imageView);
}
};
mFirebaseList.setHasFixedSize(true);
mFirebaseList.setLayoutManager(new LinearLayoutManager(TutorListActivity.this));
mFirebaseList.setAdapter(adapter);
adapter.startListening();
adapter.notifyDataSetChanged();
}
效果很好