I need to return EditText string to MainActivity as Toast how can I achieve that?

Question

Okay This is what I'm trying to make. 3 Activities. MainActivity,ActivityA & ActivityB from Main activity I'm going to ActivityA or B by Intent (Using Button). There is an EditText & a Button on each Activities A&B.. I just want to Toast the String typed on the textbox to MainActivity when I press the button on activities A or B. I provided everything below. Please someone explain what did I do wrong in the code.

Main Activity.java

package com.training.threeactivities;
import android.app.Activity;
import android.content.DialogInterface;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Button gotoA = (Button) findViewById(R.id.gotoA);
    gotoA.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intentA = new Intent(MainActivity.this, ActivityA.class);
            startActivity(intentA);
        }
    });
    Button gotoB = (Button) findViewById(R.id.gotoB);
    gotoB.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intentB = new Intent(MainActivity.this, ActivityB.class);
            startActivity(intentB);
        }
    });
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
    super.onActivityResult(requestCode, resultCode, intent);
    // check if the request code is same as what is passed  here it is 2
    if (requestCode == 1) {
        String MsgA = intent.getStringExtra("FrmA");
        Toast.makeText(MainActivity.this, MsgA, Toast.LENGTH_LONG).show();
    } else if (requestCode == 2) {
        String MsgB = intent.getStringExtra("FrmB");
        Toast.makeText(MainActivity.this, MsgB, Toast.LENGTH_LONG).show();
    }
}
}

activity_main.xml

<TextView
    android:id="@+id/txtm"
    android:paddingTop="30dp"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:text="MAIN ACTIVITY"
    android:textSize="30dp" />
<Button
    android:id="@+id/gotoA"
    android:layout_width="350dp"
    android:layout_height="150dp"
    android:layout_centerHorizontal="true"
    android:layout_below="@+id/txtm"
    android:layout_marginTop="10dp"
    android:textSize="50dp"
    android:text="GOTO A" />
<Button
    android:id="@+id/gotoB"
    android:layout_below="@+id/gotoA"
    android:layout_centerHorizontal="true"
    android:layout_width="350dp"
    android:layout_height="150dp"
    android:layout_marginTop="10dp"
    android:textSize="50dp"
    android:text="GOTO B" />

ActivityA.java

public class ActivityA extends AppCompatActivity {
EditText txtA;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_a);
    Button btnA = (Button) findViewById(R.id.btnA);
    btnA.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            txtA = (EditText) findViewById(R.id.txtA);
            String MsgFrmA = txtA.getText().toString().trim();
            Intent intentA = new Intent();
            intentA.putExtra("FrmA", MsgFrmA);
            setResult(1, intentA);
            finish();
        }
    });
}
}

activity_a.xml

 <TextView
    android:paddingTop="30dp"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:text="ACTIVITY A"
    android:textSize="30dp" />
<EditText
    android:id="@+id/txtA"
    android:layout_width="300dp"
    android:layout_height="50dp"
    android:layout_below="@+id/fa"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="150dp"
    android:background="#ffffff"
    android:hint="Type The Message" />
<Button
    android:id="@+id/btnA"
    android:layout_width="150dp"
    android:layout_height="50dp"
    android:layout_below="@+id/txtA"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="30dp"
    android:text="SEND" />

ActivityB.java

public class ActivityB extends AppCompatActivity {
EditText txtB;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_b);
    Button btnB = (Button) findViewById(R.id.btnB);
    btnB.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            txtB = (EditText) findViewById(R.id.txtB);
            String MsgFrmB = txtB.getText().toString().trim();
            Intent intentB = new Intent();
            intentB.putExtra("FrmB", MsgFrmB);
            setResult(2, intentB);
            finish();
        }
    });
}
}

activity_b.xml

   <TextView
    android:paddingTop="30dp"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:text="ACTIVITY B"
    android:textSize="30dp" />
<EditText
    android:id="@+id/txtB"
    android:layout_width="300dp"
    android:layout_height="50dp"
    android:layout_below="@+id/fa"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="150dp"
    android:background="#ffffff"
    android:hint="Type The Message" />
<Button
    android:id="@+id/btnB"
    android:layout_width="150dp"
    android:layout_height="50dp"
    android:layout_below="@+id/txtB"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="30dp"
    android:text="SEND" />

Answer 1

use startActivityForResult from your main activity