感谢您的帮助。菜单未出现，并且在回收站视图中的列表视图不可单击。
这是菜单部分。
public class QuizListActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private FirebaseAuth mAuth;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_quiz_list);
mAuth = FirebaseAuth.getInstance();
mRecyclerView = (RecyclerView)findViewById(R.id.recyclerBView);
new FirebaseDatabaseHelper().readQuiz(new FirebaseDatabaseHelper.DataStatus() {
@Override
public void DataIsLoaded(List<Quiz> quizzes, List<String> keys) {
new RecyclerConfig().setConfig(mRecyclerView, QuizListActivity.this, quizzes, keys);
}
@Override
public void DataIsInserted() {
}
@Override
public void DataIsUpdated() {
}
@Override
public void DataIsDeleted() {
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
FirebaseUser user = mAuth.getCurrentUser();
getMenuInflater().inflate(R.menu.quizlistmenu, menu);
if(user!=null) {
menu.getItem(0).setVisible(true);
menu.getItem(1).setVisible(true);
menu.getItem(2).setVisible(true);
}
return super.onCreateOptionsMenu(menu);
}
public boolean onPrepareOptionsMenu(Menu menu)
{FirebaseUser user = mAuth.getCurrentUser();
if(user!=null) {
menu.getItem(0).setVisible(true);
menu.getItem(1).setVisible(true);
menu.getItem(2).setVisible(true);
}
return super.onPrepareOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(@NonNull MenuItem item) {
switch (item.getItemId())
{
case R.id.new_book:
startActivity(new Intent(this, NewQuestionActivity.class));
return true;
case R.id.user_approval:
startActivity(new Intent(this, Approval.class));
return true;
case R.id.signout:
mAuth.signOut();
invalidateOptionsMenu();
RecyclerConfig.logout();
return true;
}
return super.onOptionsItemSelected(item);
}
}
这是菜单。
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:id="@+id/new_book"
android:title="New Question" />
<item
android:id="@+id/user_approval"
android:title="Registered User" />
<item
android:id="@+id/signout"
android:title="Sign Out" />
</menu>
这是回收站的一部分。
public class RecyclerConfig
{
FirebaseAuth mAuth;
private static FirebaseUser user;
private Context mContext;
private QuizAdapter mQuizAdapter;
public void setConfig(RecyclerView mRecyclerView, Context context, List<Quiz> quizzes, List<String> keys)
{
mAuth = FirebaseAuth.getInstance();
user = mAuth.getCurrentUser();
mContext = context;
mQuizAdapter = new QuizAdapter(quizzes, keys);
mRecyclerView.setLayoutManager(new LinearLayoutManager(context));
mRecyclerView.setAdapter(mQuizAdapter);
}
class QuizItemView extends RecyclerView.ViewHolder
{
private TextView mquestion,mans1,mans2,mans3,mans4,mcorrect,mcategoryid;
private String key;
public QuizItemView(ViewGroup parent)
{
super(LayoutInflater.from(mContext)
.inflate(R.layout.quizlistitem, parent, false));
mquestion = (TextView) itemView.findViewById(R.id.questiontv);
mans1 = (TextView) itemView.findViewById(R.id.ans1tv);
mans2 = (TextView) itemView.findViewById(R.id.ans2tv);
mans3 = (TextView) itemView.findViewById(R.id.ans3tv);
mans4 = (TextView) itemView.findViewById(R.id.ans4tv);
mcorrect = (TextView) itemView.findViewById(R.id.correcttv);
mcategoryid = (TextView) itemView.findViewById(R.id.categorytv);
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(user!=null) {
Intent intent = new Intent(mContext, QuizDetailActivity.class);
intent.putExtra("key", key);
intent.putExtra("question", mquestion.getText().toString());
intent.putExtra("answer1", mans1.getText().toString());
intent.putExtra("answer2", mans2.getText().toString());
intent.putExtra("answer3", mans3.getText().toString());
intent.putExtra("answer3", mans4.getText().toString());
intent.putExtra("answer3", mcorrect.getText().toString());
intent.putExtra("categoryid", mcategoryid.getText().toString());
mContext.startActivity(intent);
}
/*else
{
mContext.startActivity(new Intent(mContext, SignInActivity.class));
}*/
}
});
}
public void bind(Quiz quizzes, String key)
{
mquestion.setText(quizzes.getQuestion());
mans1.setText(quizzes.getAnswer1());
mans2.setText(quizzes.getAnswer2());
mans3.setText(quizzes.getAnswer3());
mans4.setText(quizzes.getAnswer4());
mcorrect.setText(quizzes.getCorrect());
mcategoryid.setText(quizzes.getCategoryid());
this.key = key;
}
}
class QuizAdapter extends RecyclerView.Adapter<QuizItemView>
{
private List<Quiz> mQuizList;
private List<String> mKeys;
public QuizAdapter(List<Quiz> mQuizList, List<String> mKeys) {
this.mQuizList = mQuizList;
this.mKeys = mKeys;
}
@NonNull
@Override
public QuizItemView onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
return new QuizItemView(parent);
}
@Override
public void onBindViewHolder(@NonNull QuizItemView holder, int position) {
holder.bind(mQuizList.get(position), mKeys.get(position));
}
@Override
public int getItemCount() {
return mQuizList.size();
}
}
public static void logout()
{
user = null;
}
}
这是登录/注册部分。
public class SignInActivity extends AppCompatActivity {
MaterialEditText edtNewEmail,edtNewPassword,edtnewName, edtnewAge, edtnewAddress, edtStatus; // for register
MaterialEditText edtEmail,edtPassword; //for Signin
Button btnRegister,btnSignIn;
FirebaseAuth mAuth;
FirebaseDatabase database;
DatabaseReference users;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sign_in);
mAuth = FirebaseAuth.getInstance();
//Firebase
database = FirebaseDatabase.getInstance();
users = database.getReference("User");
edtEmail = (MaterialEditText)findViewById(R.id.edtEmail);
edtPassword = (MaterialEditText)findViewById(R.id.edtPassword);
btnSignIn = (Button)findViewById(R.id.signInBtn);
btnRegister = (Button)findViewById(R.id.regBtn);
btnRegister.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
showSignUpDialog();
}
});
btnSignIn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
signIn(edtEmail.getText().toString(),edtPassword.getText().toString());
}
});
}
private void signIn(final String user, final String pwd) {
users.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
if(dataSnapshot.child(user).exists())
{
if(!user.isEmpty())
{
User login = dataSnapshot.child(user).getValue(User.class);
if(login.getPassword().equals(pwd))
{
Common.currentUser = login;
if(login.getStatus().equals("Admin"))
{
mAuth.signInWithEmailAndPassword(edtEmail.getText().toString(),
edtPassword.getText().toString());
Toast.makeText(SignInActivity.this, "User signed in", Toast.LENGTH_LONG).show();
Intent intent = new Intent(SignInActivity.this,QuizListActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
finish(); return;
}
else if(login.getStatus().equals("User") && login.getApproval().equals("Y"))
{
Intent homeactivity = new Intent(SignInActivity.this,Home.class);
startActivity(homeactivity);
finish();
}
else if(login.getStatus().equals("User") && login.getApproval().equals("N"))
{
Intent adminactivity = new Intent(SignInActivity.this,Home.class);
startActivity(adminactivity);
finish();
}
}
else
Toast.makeText(SignInActivity.this,"Login Failed",Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(SignInActivity.this,"Please fill in",Toast.LENGTH_SHORT).show();
}
}
else
{
Toast.makeText(SignInActivity.this,"User doesn't exist",Toast.LENGTH_SHORT).show();
}
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
}
private void showSignUpDialog() {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(SignInActivity.this);
alertDialog.setTitle("Sign Up");
//alertDialog.setMessage("Please fill full information");
LayoutInflater inflater = this.getLayoutInflater();
View activity_register = inflater.inflate(R.layout.activity_register,null);
//edtNewUserName = (MaterialEditText)activity_register.findViewById(R.id.edtNewUserName);
edtNewEmail = (MaterialEditText)activity_register.findViewById(R.id.edtNewEmail);
edtNewPassword = (MaterialEditText)activity_register.findViewById(R.id.edtNewPassword);
edtnewName = (MaterialEditText)activity_register.findViewById(R.id.edtnewName);
edtnewAge = (MaterialEditText)activity_register.findViewById(R.id.edtnewAge);
edtnewAddress = (MaterialEditText)activity_register.findViewById(R.id.edtnewAddress);
edtStatus = (MaterialEditText)activity_register.findViewById(R.id.edtStatus);
alertDialog.setView(activity_register);
//alertDialog.setIcon(R.drawable.ic_account_circle_black_24dp);
alertDialog.setNegativeButton("No", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
dialogInterface.dismiss();
}
});
alertDialog.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
final User user = new User(edtNewEmail.getText().toString(),
edtNewPassword.getText().toString(),edtnewName.getText().toString(),
edtnewAge.getText().toString(),edtnewAddress.getText().toString(),edtStatus.getText().toString(),
"N");
users.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
if(dataSnapshot.child(user.getEmail()).exists())
Toast.makeText(SignInActivity.this,"User already exist.",Toast.LENGTH_LONG).show();
else
{
if(dataSnapshot.child(user.getStatus()).exists() && user.getStatus() == "Admin")
{
mAuth.createUserWithEmailAndPassword(edtNewEmail.getText().toString(),
edtNewPassword.getText().toString())
.addOnCompleteListener(new OnCompleteListener<AuthResult>() {
@Override
public void onComplete(@NonNull Task<AuthResult> task) {
if(task.isSuccessful())
{
FirebaseDatabase.getInstance().getReference("User")
.child(FirebaseAuth.getInstance().getCurrentUser().getUid()).setValue(user);
}
}
});
}
else {
users.child(user.getEmail())
.setValue(user);
Toast.makeText(SignInActivity.this, "User registered.", Toast.LENGTH_LONG).show();
}
}
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
dialogInterface.dismiss();
}
});
alertDialog.show();
}
}
登录和注册的效果很好，然后登录后可以正确显示列表回收者视图，但没有出现菜单，并且无法单击回收者视图。
对于菜单，它先前声明为空引用或其他内容。
答案 0 :(得分：0)
对于第一个问题，这就是为什么未初始化FirebaseUser而不显示菜单的原因。您需要通过方法onCreate对其进行初始化。
在课堂上。
private FirebaseUser user;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_quiz_list);
mAuth = FirebaseAuth.getInstance();
user = mAuth.getCurrentUser();
}
接下来，在您的onCreateOptionsMenu。
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.quizlistmenu, menu);
if(user!=null) {
menu.getItem(0).setVisible(true);
menu.getItem(1).setVisible(true);
menu.getItem(2).setVisible(true);
}
return super.onCreateOptionsMenu(menu);
}