Edittext.gettext on a null Object Reference

Question

I am trying to add records in the Firebase Realtime Database, through a Alertdialog, but the Edittext components do not let me abstract the component information.

Below is the section of java..

fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(final View view) {
            //Alerta para alterar informações do usuario.
            Snackbar.make(view, "Adicionando um novo registro", Snackbar.LENGTH_LONG)
                    .setAction("Registro", null).show();
            AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
            LayoutInflater inflater = (MainActivity.this).getLayoutInflater();
            builder.setTitle("Registro");
            builder.setView(inflater.inflate(R.layout.fab_registro,null));
            builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int id) {
                    EditText data , nome , idade , horaExame , procedimento ,qtsPeliculas ;
                    nome = findViewById(R.id.registro_nome);
                    data = findViewById(R.id.registro_data);
                    horaExame = findViewById(R.id.registro_hora);
                    idade = findViewById(R.id.registro_idade);
                    qtsPeliculas = findViewById(R.id.registro_peliculas);
                    procedimento = findViewById(R.id.registro_procedimento);
                    database = FirebaseDatabase.getInstance();
                    DatabaseReference myRef = database.getReference("Paciente");
                    String child = nome.getText().toString();

                    myRef.child(child).child("hora_exame").setValue("enrique");
                    myRef.child(child).child("procedimento").setValue("toráx");
                    myRef.child(child).child("peliculas").setValue("3");

                    myRef.child(child).child("data").setValue("23456");
                    myRef.child(child).child("idade").setValue("42");
                    myRef.child(child).child("nome").setValue("enriqeu");

                }
            });
            builder.setNegativeButton("Cancelar", null);
            builder.create();
            builder.show();
        }
    });

This is the Logcat of error

Attempt to invoke virtual method 'void android.widget.EditText.getText(java.lang.CharSequence)' on a null object reference
    at com.martel.unimedradiologia_controledeestoque.MainActivity$1$1.onClick(MainActivity.java:63)
    at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:164)

xml layout is all right, both type and id.

Answer 1

Dude, I’m finding it strange the edittext being instantiated at the click of the button (Edittext name... name = findBiewById(...)). The conventional is to instantiate each view in onCreate.

Another strange thing about the block of code you sent is that the casting was not done (the correct one would be: Edittext name = (Edittext) findViewById(...)).

Review those issues that are probably related to the cause of this problem.

Answer 2

You were trying to retrieve the object in your MainActivity, however these objects were not inflated in the MainActivity you have to use the reference of View inflated to retrieve objects referenced by R.id..

Just create a variable of your View customized that was passing to the AlertDialog and use the findViewById this reference created and not the MainActivity

fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(final View view) {
            //Alerta para alterar informações do usuario.
            Snackbar.make(view, "Adicionando um novo registro", Snackbar.LENGTH_LONG)
                    .setAction("Registro", null).show();
            AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
            LayoutInflater inflater = (MainActivity.this).getLayoutInflater();
            builder.setTitle("Registro");
            View view = inflater.inflate(R.layout.fab_registro,null);
            builder.setView(view);
            builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int id) {
                    EditText data , nome , idade , horaExame , procedimento ,qtsPeliculas ;
                    nome = view.findViewById<EditText>(R.id.registro_nome);
                    data = view.findViewById<EditText>(R.id.registro_data);
                    horaExame = view.findViewById<EditText>(R.id.registro_hora);
                    idade = view.findViewById<EditText>(R.id.registro_idade);
                    qtsPeliculas = view.findViewById<EditText>(R.id.registro_peliculas);
                    procedimento = view.findViewById<EditText>(R.id.registro_procedimento);
                    database = FirebaseDatabase.getInstance();
                    DatabaseReference myRef = database.getReference("Paciente");
                    String child = nome.getText().toString();

                    myRef.child(child).child("hora_exame").setValue("enrique");
                    myRef.child(child).child("procedimento").setValue("toráx");
                    myRef.child(child).child("peliculas").setValue("3");

                    myRef.child(child).child("data").setValue("23456");
                    myRef.child(child).child("idade").setValue("42");
                    myRef.child(child).child("nome").setValue("enriqeu");

                }
            });
            builder.setNegativeButton("Cancelar", null);
            builder.create();
            builder.show();
        }
    });