Android | Working With Button

1. activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<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=".MainActivity">

<EditText
android:id="@+id/etname"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:hint="Enter Your Name"
android:padding="10dp"
android:textStyle="bold" />

<Button
android:id="@+id/btnsave"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:padding="20dp"
android:text="Save" />

<TextView
android:id="@+id/tvvalue"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:padding="10dp"
android:textStyle="bold" />

</LinearLayout>

2. MainActivity.java

package com.example.button;

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

public class MainActivity extends AppCompatActivity {

EditText etname;
Button btnsave;
TextView tvvalue;
String value;

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

etname = findViewById(R.id.etname);
btnsave = findViewById(R.id.btnsave);
tvvalue = findViewById(R.id.tvvalue);

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

value = etname.getText().toString();
tvvalue.setText(value);
}
});
}
}

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