TextView and EditText in Android

1. How to use simple TextView in android

Write this code in .xml file

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="30sp"
        android:textColor="#195ced"
        android:textAlignment="center"
        android:text="Hello android"/>

</LinearLayout>

2. How to use simple EditText in android

Write this code in .xml file

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <EditText
        android:id="@+id/edittext"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="numberPassword"
        android:hint="Enter password here"
        />

</LinearLayout>

3. How to get the value from EditText in android

Step 1:Write this code in .xml file

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <EditText
        android:id="@+id/et"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Enter the data"/>
    <Button
        android:id="@+id/btn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Get Value"/>


</LinearLayout>

Step 2:Write this code in .java file

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    Button button;
    EditText editText;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        editText=(EditText)findViewById(R.id.et);
        button=(Button)findViewById(R.id.btn);
        button.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        String value=editText.getText().toString();
        Toast.makeText(this,"Value is "+value,Toast.LENGTH_SHORT).show();
    }
}

4. EditText input to TextView output

Step 1:Write this code in .xml file

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:orientation="vertical"
    android:layout_height="match_parent">

    <EditText
        android:id="@+id/edittext"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Enter your text"
        />
    <Button
        android:id="@+id/btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="Get Value"/>
    <TextView
        android:id="@+id/textview"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="30sp"
        android:textColor="#195ced"
        android:textAlignment="center"
        android:text=""/>

</LinearLayout>

Step 2:Write this code in .java file

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    EditText editText;
    Button button;
    TextView textView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        editText=(EditText)findViewById(R.id.edittext);
        button=(Button)findViewById(R.id.btn);
        button.setOnClickListener(this);
        textView=(TextView)findViewById(R.id.textview);
    }

    @Override
    public void onClick(View view) {
        String value=editText.getText().toString();
        textView.setText("Your text is "+value);
    }
}

5. Build a simple Calculator using EditText and TextView in android

Step 1:Write this code in .xml file

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.example.toto.mycalc.MainActivity">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:textSize="50sp"
            android:text="Calculator"/>
    </LinearLayout>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textSize="30sp"
            android:text="First Number"/>
        <EditText
            android:id="@+id/firstno"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="5dp"
            android:inputType="number"
            android:hint="Enter the First Number"/>
    </LinearLayout>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:layout_marginTop="5dp">
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="5dp"
            android:textSize="30sp"
            android:text="Second Number"/>
        <EditText
            android:id="@+id/secondno"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:inputType="number"
            android:hint="Enter the Second Number"/>
    </LinearLayout>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:weightSum="4"
        android:orientation="horizontal">
        <Button
            android:id="@+id/badd"
            android:layout_weight="1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Add (+)"/>
        <Button
            android:id="@+id/bsub"
            android:layout_weight="1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Sub (-)"/>
        <Button
            android:id="@+id/bmul"
            android:layout_weight="1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Mul (*)"/>
        <Button
            android:id="@+id/bdiv"
            android:layout_weight="1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Div (/)"/>
    </LinearLayout>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp">
        <TextView
            android:id="@+id/tvresult"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textSize="30sp"/>
    </LinearLayout>

</LinearLayout>

Write this code in .java file

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    private Button badd, bsub, bmul, bdiv;
    private TextView tvresult;
    private EditText firstno, secondno;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        init();
    }

    private void init() {
        badd = (Button) findViewById(R.id.badd);
        bsub = (Button) findViewById(R.id.bsub);
        bmul = (Button) findViewById(R.id.bmul);
        bdiv = (Button) findViewById(R.id.bdiv);
        firstno = (EditText) findViewById(R.id.firstno);
        secondno = (EditText) findViewById(R.id.secondno);
        tvresult = (TextView) findViewById(R.id.tvresult);
        badd.setOnClickListener(this);
        bsub.setOnClickListener(this);
        bmul.setOnClickListener(this);
        bdiv.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        String num1 = firstno.getText().toString();
        String num2 = secondno.getText().toString();
        switch (view.getId()) {
            case R.id.badd:
                int addition = Integer.parseInt(num1) + Integer.parseInt(num2);
                tvresult.setText("Addition : " + String.valueOf(addition));
                break;
            case R.id.bsub:
                int subtraction = Integer.parseInt(num1) - Integer.parseInt(num2);
                tvresult.setText("Subtraction : " + String.valueOf(subtraction));
                break;
            case R.id.bmul:
                int multiplecation = Integer.parseInt(num1) * Integer.parseInt(num2);
                tvresult.setText("Multiplecation : " + String.valueOf(multiplecation));
                break;
            case R.id.bdiv:
                try {
                    float division = Float.parseFloat(num1) / Float.parseFloat(num2);
                    tvresult.setText("Division : " + String.valueOf(division));
                } catch (Exception e) {
                    tvresult.setText("Can not Division posible");
                }
                break;
        }
    }
}