The Ideal is for you to use SharedPreferences for this. When entering the slide screen, you must save a "ECRA_TAL_FOI_ABERTO" flag as true. And when entering the app, you should check if that flag exists.Boolean b = verificarSeExisteAFlag() if(b){ vaiParaEcraPrincipal() }else{ vaiParaEcraDeSlides() } When you enter the slides you should:salvarFlag(true) Shared preferences are stored while the app has been installed. And removed when the app is desisted.References https://developer.android.com/reference/android/content/SharedPreferences

Opa, blza?! As you doubted where and when you recovered the values in your activity A, I posted the full code.In your Activity A:public class MainActivity extends AppCompatActivity { //declarando os campos de valores EditText valor1, valor2; //Botao para a proxima intent Button botaoProximaIntent; //valores double para a proxima intent double a, b; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); valor1 = findViewById(R.id.valor1); valor2 = findViewById(R.id.valor2); botaoProximaIntent = findViewById(R.id.botaoProximaIntent); //click no botao botaoProximaIntent.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //faça as validacoes antes de pegar os valores //resgate seu double A do editText a = Double.parseDouble(valor1.getText().toString()); //resgate seu double A do editText b = Double.parseDouble(valor2.getText().toString()); //agora temos o valor de a e b, vamos chamar a proxima intent e passar os parametros Intent intent = new Intent(MainActivity.this, SegundaActivity.class); //declaramos o bundle Bundle params = new Bundle(); //parametros do bundle params.putDouble("valor1", a); params.putDouble("valor2", b); intent.putExtras(params); //chamamos a proxima intent startActivity(intent); } }); } } In your Activity B, receive the values:public class SegundaActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_segunda); //declarando os valores double a, b; // pegando os parametros intent Intent intent = getIntent(); //validando a intent if (intent != null) { Bundle params = intent.getExtras(); //validando se há parametros if (params != null) { //resgatando os valores na segunda intent a = params.getDouble("valor1"); b = params.getDouble("valor2"); } } } }

I suggest you try with findViewById (android.R.id.content).This is what worked for me:Snackbar.make(findViewById(android.R.id.content), resp.getMessage(), Snackbar.LENGTH_LONG).show(); That's it.

This is a bug: https://issuetracker.google.com/issues/122829431 .The problem has been solved, and will be available in the next https://issuetracker.google.com/issues/122829431#comment7 :For the shadow in LinearLayout, actually we use it to indicate the direction of LinearLayout. But we agree it is even annoying for seeing a clear preview.So we remove that shadow when LinearLayout is not selected. It would be release in the following version.

You can use:listmarcacoes.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView adapter, View viw, int posicao,long id) { cursor.moveToPosition(posicao); Intent intent = new Intent(getActivity(), EdicaoMarcacao.class); Bundle params = new Bundle(); String resposta = cursor.getString(1).toString(); if(CalculoHora.isHojeData(resposta)){ Toast.makeText(getActivity(), "Use a aba RESGISTRO para marcações do dia!", Toast.LENGTH_SHORT).show(); } else { params.putString("diafiltro", resposta); intent.putExtras(params); startActivityForResult(intent, 9);//9 é o requestCode número inteiro para a identificação } } }); Then overwrite the method:@Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { if (requestCode == 9 && resultCode == RESULT_OK) { Bundle params = data.getExtras(); String resposta = params.getString("diafiltro"); lista(); } } In the activity EdicaiMarcao do:@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Bundle params = getIntent().getExtras(); String resposta = params.getString("diafiltro"); } Then make the changes you want and when you finish performing the EdicaiMarcao activity. class do:(obs:na EdicaiMarcao.class)Bundle params = new Bundle(); params.putString("diafiltro", resposta); intent.putExtras(params); setResult(RESULT_OK, intent); finish();

I managed to solve this wayin the method save private fun save() { val nome = edit_nome_Pessoa.text.toString() val idade = ("" + (seekbarIdade.progress + 10) + " anos") val sexo_Id = findViewById&lt;RadioGroup&gt;(R.id.radioGroup_sexo_Pessoa) val sexo = (if (sexo_Id.checkedRadioButtonId == R.id.radio_feminino_Pessoa) "Feminino" else "Masculino").toString() val dt_nasc = edit_calendar_Pessoa.text.toString().substring(24..33) val rg = edit_rg_Pessoa.text.toString() val cpf = edit_cpf_Pessoa.text.toString() val rua = edit_rua_Pessoa.text.toString() val num_casa = editNumeroCasa_Pessoa.text.toString() val bairro = edit_bairro_Pessoa.text.toString() val complemento = edit_comeplemento_Pessoa.text.toString() val cep = edit_cep_Pessoa.text.toString() val cidade = edit_cidade_Pessoa.text.toString() val estado = edit_uf_Pessoa.text.toString() val telefone = edit_telefone_Pessoa.text.toString() val local_estudo = edit_escola_Pessoa.text.toString() val nome_mae = edit_mae_Pessoa.text.toString() val nome_pai = edit_pai_Pessoa.text.toString() val resposavel = edit_resp_Pessoa.text.toString() val rg_resp = edit_rg_resp_Pessoa.text.toString() val cpf_resp = edit_cpf_resp_Pessoa.text.toString() val telefone_resp = edit_tel_resp_Pessoa.text.toString() mRegraNegocio_Pessoa.inserir_Pessoa_Businnes( nome, idade, sexo, dt_nasc, rg, cpf , rua, num_casa, bairro, complemento, cep, cidade, estado , telefone, local_estudo, nome_mae, nome_pai , resposavel, rg_resp, cpf_resp, telefone_resp) Toast.makeText(this, "preencher os campos", Toast.LENGTH_LONG).show() finish() } in validation functionfun valida() : Boolean { val name = findViewById(R.id.edit_name_Person) if (name.text.length == 0) { name.setError() Please fill in required field") } /* val idade = findViewById<SeekBar>(R.id.seekBar_Idade_Pessoa) if (idade.text.length == 0) idade.setError("Por favor preenche campo obrigatório")*/ val sexo = findViewById&lt;RadioGroup&gt;(R.id.radioGroup_sexo_Pessoa) if (nome.text.length == 0) nome.setError("Por favor preenche campo obrigatório") val dt_nasc = findViewById&lt;TextView&gt;(R.id.edit_calendar_Pessoa) if (dt_nasc.text.length == 0) dt_nasc.setError("Por favor preenche campo obrigatório") val rg = findViewById&lt;EditText&gt;(R.id.edit_rg_Pessoa) if (rg.text.length == 0) rg.setError("Por favor preenche campo obrigatório") val cpf = findViewById&lt;EditText&gt;(R.id.edit_cpf_Pessoa) if (cpf.text.length == 0) cpf.setError("Por favor preenche campo obrigatório") val rua = findViewById&lt;EditText&gt;(R.id.edit_rua_Pessoa) if (rua.text.length == 0) rua.setError("Por favor preenche campo obrigatório") val num_casa = findViewById&lt;EditText&gt;(R.id.editNumeroCasa_Pessoa) if (num_casa.text.length == 0) num_casa.setError("Por favor preenche campo obrigatório") val bairro = findViewById&lt;EditText&gt;(R.id.edit_bairro_Pessoa) if (bairro.text.length == 0) bairro.setError("Por favor preenche campo obrigatório") val complemento = findViewById&lt;EditText&gt;(R.id.edit_comeplemento_Pessoa) if (complemento.text.length == 0) complemento.setError("Por favor preenche campo obrigatório") val cep = findViewById&lt;EditText&gt;(R.id.edit_cep_Pessoa) if (cep.text.length == 0) cep.setError("Por favor preenche campo obrigatório") val cidade = findViewById&lt;EditText&gt;(R.id.edit_cidade_Pessoa) if (cidade.text.length == 0) cidade.setError("Por favor preenche campo obrigatório") val estado = findViewById&lt;EditText&gt;(R.id.edit_uf_Pessoa) if (rg.text.length == 0) rg.setError("Por favor preenche campo obrigatório") val telefone = findViewById&lt;EditText&gt;(R.id.edit_telefone_Pessoa) if (telefone.text.length == 0) telefone.setError("Por favor preenche campo obrigatório") val local_estudo = findViewById&lt;EditText&gt;(R.id.edit_escola_Pessoa) if (local_estudo.text.length == 0) local_estudo.setError("Por favor preenche campo obrigatório") val nome_mae = findViewById&lt;EditText&gt;(R.id.edit_mae_Pessoa) if (nome_mae.text.length == 0) nome_mae.setError("Por favor preenche campo obrigatório") val nome_pai = findViewById&lt;EditText&gt;(R.id.edit_pai_Pessoa) if (nome_pai.text.length == 0) nome_pai.setError("Por favor preenche campo obrigatório") val resposavel = findViewById&lt;EditText&gt;(R.id.edit_resp_Pessoa) if (resposavel.text.length == 0) resposavel.setError("Por favor preenche campo obrigatório") val rg_resp = findViewById&lt;EditText&gt;(R.id.edit_rg_resp_Pessoa) if (rg_resp.text.length == 0) rg_resp.setError("Por favor preenche campo obrigatório") val cpf_resp = findViewById&lt;EditText&gt;(R.id.edit_cpf_resp_Pessoa) if (cpf_resp.text.length == 0) cpf_resp.setError("Por favor preenche campo obrigatório") val telefone_resp = findViewById&lt;EditText&gt;(R.id.edit_tel_resp_Pessoa) if (telefone_resp.text.length == 0) telefone_resp.setError("Por favor preenche campo obrigatório") return nome.length() &gt; 0 /*&amp;&amp; idade.length &gt; 0 &amp;&amp; sexo.length &gt; 0*/ &amp;&amp; dt_nasc.length() &gt; 0 &amp;&amp; rg.length() &gt; 0 &amp;&amp; cpf.length() &gt; 0 &amp;&amp; rua.length() &gt; 0 &amp;&amp; num_casa.length() &gt; 0 &amp;&amp; bairro.length() &gt; 0 &amp;&amp; complemento.length() &gt; 0 &amp;&amp; cep.length() &gt; 0 &amp;&amp; cidade.length() &gt; 0 &amp;&amp; estado.length() &gt; 0 &amp;&amp; telefone.length() &gt; 0 &amp;&amp; local_estudo.length() &gt; 0 &amp;&amp; nome_mae.length() &gt; 0 &amp;&amp; nome_pai.length() &gt; 0 &amp;&amp; resposavel.length() &gt; 0 &amp;&amp; rg_resp.length() &gt; 0 &amp;&amp; cpf_resp.length() &gt; 0 &amp;&amp; telefone_resp.length() &gt; 0 } in the onclice method where I call the click save check firstif (id == R.id.btn_salvar) { if (valida() { save() ) }

I believe you missed @Override in this part of the code listaAlunos.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemCIick(AdapterView<?> lista, View item, int position, long id) { Aluno aluno = (Aluno) listaAlunos.getItemAtPosition(position); Intent intentVaiProFormulario = new Intent(ListaAlunosActivity.this, FormularioActivity.class); intentVaiProFormulario.putExtra("aluno", aluno); startActivity(intentVaiProFormulario); } });

The problem is in the builder FormularioHelper which is used in Activity:public boolean onOptionsItemSelected(MenuItem item) { FormularioHelper helper = new FormularioHelper(this); // <-- AQUI ... mais códigos ... Your builder is like this:public FormularioHelper(FormularioActivity activity) { EditText campoNome = activity.findViewById(R.id.nome); EditText campoEndereco = activity.findViewById(R.id.endereco); EditText campoSitesPessoais = activity.findViewById(R.id.sitesPessoais); EditText campoTelefone = activity.findViewById(R.id.telefone); RatingBar campoNotas = (RatingBar) activity.findViewById(R.id.notas); } His idea, apparently, was to setate the attributes of this class. But that's not what you did! There you create 5 NEW variables that are not being used.So when you try to recover the values of the Views they are null by causing this error:'android.text.Editable android.widget.EditText.getText()' on a null object reference For as the message said, the reference (the id) is void.To arrange this, just do the following:public FormularioHelper(FormularioActivity activity) { this.campoNome = activity.findViewById(R.id.nome); this.campoEndereco = activity.findViewById(R.id.endereco); this.campoSitesPessoais = activity.findViewById(R.id.sitesPessoais); this.campoTelefone = activity.findViewById(R.id.telefone); this.campoNotas = (RatingBar) activity.findViewById(R.id.notas); }

Your question is not very clear, but what you want is probably to pass data between Activities. For this, you will need one https://developer.android.com/reference/android/content/Intent .Supposing you have generated a int and want to pass it in Activities:int seuNumero = 10; Intent intent = new Intent(SUA_ACTIVITY_ATUAL.class, ACTIVITY_DE_DESTINO.class); intent.putExtra("seuNumero", seuNumero); startActivity(intent); Na Activity target, you need the following code to recover your number:int numero = getIntent().getIntExtra("seuNumero"); Mind the method getIntExtra(). It is used to recover a type value int. If you are dealing with double, go use getDoubleExtra() etc.

Luis, Apparently it is sending an object with null reference.You did not instantiate your "auth" variable.Just stand it this way in your onCreate(): auth = FirebaseAuth.getInstance();

The problem is, startActivity() server to start an activity and not a fragment,to handle fragments you need a FragmentTransaction, to start your fragment you should do the following:PerfilFragment perfilFrag = new PerfilFragment(); FragmentTransaction ft = getSupportFragmentManager().beginTransaction(); ft.add(R.id.fragmentContainer, perfilFrag, perfilFrag.getTag()); //Você pode criar sua própria tag ft.commit(); R.id.fragmentContainer is a View of your layout that you will use to show your fragments, add() add the fragment to this View if you want to replace the fragment you will use replace(), more information about the creation and use of fragments you can find in https://developer.android.com/guide/components/fragments of android.

The error is in the statement:TextView nomeView = (EditText) findViewById(R.id.emailPrincipal); It is a TextView, but after = you are placing (EditText).There's nothing to do with the Bundle or Intent.

Some things you can try:Constants. ♪public final class Constantes { // TODO: Revisar o ID public static final String UID_ADMIN = "dGVzdGVAdGVzdGUuY29t"; private Constantes() { // Sem instâncias } } Function to open the screenprivate void openRestrictedSettings() { if (allowRestrictedSettings()) { Intent intentRestrictedSettings = new Intent(TelaPrincipalActivity.this, ActivityRestrictedSettings.class); startActivity(intentRestrictedSettings); } } private boolean allowRestrictedSettings() { /* Supondo que há um sistema de login com firebase e que você já tem uma classe UserEmail com o campo "id" e um objeto dessa classe disponível para verificação */ FirebaseUser currentUser = FirebaseAuth.getInstance().getCurrentUser(); if (currentUser == null) { Toast.makeText(this, "Por favor, faça login com sua conta", Toast.LENGTH_SHORT).show(); return false; } String userId = userEmail.getUid(); String userPermissions = userEmail.getuserPermissions(); if (!userId.equals(Constantes.UID_ADMIN)) { Toast.makeText(this, "Apenas usuários autorizados podem acessar as configurações", Toast.LENGTH_SHORT).show(); return false; } if (TextUtils.isEmpty(userPermissions) || !userPermissions.equals("admin")) { Toast.makeText(this, "Apenas usuários autorizados podem acessar as configurações", Toast.LENGTH_SHORT).show(); return false; } // Ou direto pelo firebase auth if (!currentUser.getUid().equals(Constantes.UID_ADMIN)) { Toast.makeText(this, "Apenas usuários autorizados podem acessar as configurações", Toast.LENGTH_SHORT).show(); return false; } return true; }

The error occurs because you are trying to access Android components before Activity is created, i.e. before the method onCreate() be called. Two examples of these calls illegal are in:public EditText txtAreaSend = findViewById(R.id.textBox); public LayoutInflater messageInflater = (LayoutInflater) getSystemService(Activity.LAYOUT_INFLATER_SERVICE); Notice that these variables are being initialized in the class body, when in fact, they should be initialized after or within the method onCreate(). Therefore, a solution would be to declare these variables in the class body, but only to initialize them within the onCreate()or in some other method;ExampleIn the class body:public EditText txtAreaSend; public LayoutInflater messageInflater; Within the method onCreate()or some other method:messageInflater = (LayoutInflater) getSystemService(Activity.LAYOUT_INFLATER_SERVICE); txtAreaSend = findViewById(R.id.textBox); ExtraIt would be nice for you to take a look at https://developer.android.com/guide/components/activities?hl=pt-br to have a better idea about when to call certain methods and initialize their variables.

How about overwriting the method onBackPressed() DadosActivity and put there again the call to the Intent? This method is called when you press back and by default it finishes the Current Activity. As you are coming back to your first, it means that the Intent does not enter the pile Activities, therefore there would be no way to return to it naturally without a new call.@Override public void onBackPressed() { super.onBackPressed(); //comportamento padrão - finaliza Activity atual //chamada para o Intent } Edit: To reuse code as you asked in comments, the simplest option would be to create a class with the code that is used by the two Activities and reuse. But if you want to enjoy the code of MainActivity some changes will be needed. You would have to receive a message from DadosActivity when you came back and did a treatment for when you received this message make direct the code to choose image. For this use startActivityForResult to call DadosActivity and DadosActivity you use setResult with a specific code. Na MainActivity in the method onActivityResult, which is returned after finishing the DadosActivity in return, you treat this code and make the call Intent for photo choice. A little job, but I think it'll be better.

Could you do some tests?OnCreate() from your BaseActivity seal contentView.setContentView(R.layout."SeuLayout")Try to tap into the hand which activity is your launcher, following your second screenshot, where it is "Default Activity" changes to "Specified Activity" and in the field below selects your base activity.

Here is the problem:Button btnLogar = findViewById(R.id.btnEntrar); Replace with:Button btnLogar = (Button)findViewById(R.id.btnEntrar); And it should work again, another alternative is to create a method in your activity and call it in the layout:public void abreOutraActivity(View v){ } And in the layout: <Button android:id="@+id/btnEntrar" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/btnEntrar" android:textColor="@color/white" android:textSize="20sp" android:onClick="abreOutraActivity" />

Basically, the methods of the Activity life cycle have their running moments.See below:onCreate(): It is the first function to be performed in an Activity. It is usually responsible for loading XML layouts and other boot operations. It is executed only once;onStart(): It is called immediately after onCreate() – and also when an Activity that was in the background refocused;onResume(): Just like onStart(), it is called on Activity startup and also when an Activity refocuses. What's the difference between the two? OnStart() is only called when Activity was no longer visible and refocused, onResume() is called in the “focus logs”;onPause(): It is the first function to be invoked when Activity loses focus (this occurs when a new Activity is started);onStop(): It is only called when Activity gets completely covered by another Activity;onDestroy(): The last function to be performed. After it, Activity is considered “dead” – that is, it can no longer be re-released. If the user requests this Activity again, a new object will be built;onRestart(): Called immediately before onStart(), when an Activity refocuses after being in background.Source: Article Understanding the life cycle of an Android application | DEVMEDIA

What language are you using? it's just to do a if .. if you post your code I'll help you better, but you'd be something like that.if (checkboxMasculino.Checked) { //codigo do botao masculino } else if (checkboxFeminino.Checked) { //codigo do botao feminino }

Function of each method of a Activity:onCreate() - It's the first function to run in an Activity. It is usually responsible for loading XML layouts and other boot operations. It is executed only once.onStart() - It is called immediately after onCreate() – and also when an Activity that was in the background comes back to focus.onResume() - Just like onStart(), it is called on Activity startup and also when an Activity refocuses. What's the difference between the two? OnStart() is only called when Activity was no longer visible and refocused, onResume() is called in the “focus removals”.onPause() - It is the first function to be invoked when Activity loses focus (this occurs when a new Activity is started) .onStop() - It's only called when Activity gets completely covered by another Activity.onDestroy() - The last function to be performed. After it, Activity is considered “dead” – that is, it can no longer be re-released. If the user requests this Activity again, a new object will be built.onRestart() - Called immediately before onStart(), when an Activity comes back to focus after being in background.Now let's imagine that the user was browsing your application and suddenly clicked on the HOME button what happens in your app:Android will call the methods: onPause() and onStop().If the user returns to your app then thenRestart(), onStart() and onResume() and your app will work again.Now let's imagine that the user is within your application and click on a button calling another Activity. It navigates the new Activity and suddenly it clicks the button What happens to our Activities?Android will call the method onPause() of the second Activity thus pausing any interaction.The methods will be called: onRestart(), onStart() and onResume() from the previous Activity.If everything happens well then android calls the methods onStop() and onDestroy() of the second activity thus killing the second screen and showing the first screen beautiful and ready to work. To identify the steps, you can do as follows: Right Button>Generate>Override Methods(Rewrite Methods), and add the onCreate, onStart, onStop, onDestroy, on Restart... You will be added to Activity. java the following commands for each selected method: protected void onStart() { super.onStart(); } protected void onRestart() { super.onRestart(); } ...and so for all methods. To identify the step you find, you can add a message on the screen in each method, with the step description, for example, in the onStart method add: Toast.makeText(getApplicationContext(),"onStart Metodo Chamado", Toast.LENGTH_SHORT).show(); As follows: protected void onStart() { super.onStart(); Toast.makeText(getApplicationContext(),"onStart Metodo Chamado", Toast.LENGTH_SHORT).show(); } http://www.devmedia.com.br/entendendo-o-ciclo-de-vida-de-uma-aplicacao-android/22922