AndroidBullOfficial

  UploadResults.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                //get EditText into the String format
                final String StudentRollNo = RollNo.getText().toString();
                final String StudentTotalMarks = TotalMarks.getText().toString();
                String StudentObtainedMarks =  ObtainedMarks.getText().toString();

AndroidBullOfficial

public class MainActivity extends AppCompatActivity {

    //Declare globally
    TextView logout;
    EditText RollNo,TotalMarks,ObtainedMarks;
    TextView UploadResults,SeeMarksDetails;
    FirebaseAuth mAuth;
    FirebaseDatabase database;
    DatabaseReference myRef;

AndroidBullOfficial

@Override
    protected void onStart()
    {
        super.onStart();
        if (currentUser != null)            //check if current user is logged in
        {
            sendUserToMainActivity();
        }
    }

AndroidBullOfficial

mAuth.signInWithEmailAndPassword(email, password)                       //use Firebase method to signin
                    .addOnCompleteListener(this, new OnCompleteListener<AuthResult>()
                    {
                        @Override
                        public void onComplete(@NonNull Task<AuthResult> task)
                        {
                            if (task.isSuccessful())
                            {
                                // Sign in success, update UI with the signed-in user's information
                                Toast.makeText(LoginActivity.this, "Login Successful!!!", Toast.LENGTH_SHORT).show();

AndroidBullOfficial

  //When the btn is clicked
        CreateAccount.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                //get EditText into the String format
                final String FullName = fullName.getText().toString();
                final String email = emailEdtText.getText().toString();
                String password =  passwordEdtText.getText().toString();
                String repeatPassword =  RepeatPasswordEdtText.getText().toString();

AndroidBullOfficial

public class SignUp extends AppCompatActivity {

    //Declare globally
    TextView GoToSignIn, CreateAccount;
    EditText fullName,emailEdtText,passwordEdtText,RepeatPasswordEdtText;
    RadioButton radioMale,radioFeMale;
    FirebaseAuth mAuth;
    FirebaseDatabase database;
    DatabaseReference myRef;
    String gender="";

AndroidBullOfficial

package com.arslan6015.loginwithgoogle;


import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

AndroidBullOfficial

   //Update a node in database
        update = findViewById(R.id.update);
        update.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                FirebaseDatabase database1 = FirebaseDatabase.getInstance();
                DatabaseReference reference = database1.getReference().child("message").child("java").child("user");
                reference.setValue("arslan khan")
                        //you can also attach listenr just to know whetehr it is successful or not
                        .addOnSuccessListener(new OnSuccessListener<Void>() {

AndroidBullOfficial

//Delete Node data from database
        button2 = findViewById(R.id.button2);
        button2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                DatabaseReference dbNode = FirebaseDatabase.getInstance().getReference().getRoot().child("python").child("user");
                dbNode.setValue(null);
                //or you can delte the node with the following code also
                DatabaseReference dbNodetwo = FirebaseDatabase.getInstance().getReference().getRoot()
                        .child("php").child("User");

AndroidBullOfficial

//For recyclerView
    implementation "androidx.recyclerview:recyclerview:1.1.0"
    // For control over item selection of both touch and mouse driven selection
    implementation "androidx.recyclerview:recyclerview-selection:1.1.0-rc01"