Hitung Luas & Keliling Lingkaran

#HitungLingkaranLain

Source Code .xml & .java
Hitung Luas & Keliling Lingkaran Android Studio

Reference :
http://nasibmarbun93.blogspot.com/2015/03/program-android-menghitung-luas-dan.html

main_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="22dp"
        android:layout_marginTop="20dp"
        android:text="Menghitung Lingkaran"
        android:layout_centerHorizontal="true"
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <EditText
        android:id="@+id/ejari"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/textView2"
        android:layout_alignBottom="@+id/textView2"
        android:layout_marginLeft="20dp"
        android:layout_toRightOf="@+id/textView2"
        android:ems="10" >

        <requestFocus />
    </EditText>

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textView1"
        android:layout_below="@+id/textView1"
        android:layout_marginTop="33dp"
        android:text="Jari-jari" />

    <Button
        android:id="@+id/btnhapus"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/btnproses"
        android:layout_alignBottom="@+id/btnproses"
        android:layout_marginLeft="20dp"
        android:layout_toRightOf="@+id/textView1"
        android:onClick="myClickHandler"
        android:text="Hapus" />

    <TextView
        android:id="@+id/textView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/eluas"
        android:layout_alignBottom="@+id/eluas"
        android:layout_alignLeft="@+id/textView2"
        android:text="Luas" />

    <TextView
        android:id="@+id/textView4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/ekeliling"
        android:layout_alignBottom="@+id/ekeliling"
        android:layout_alignRight="@+id/textView3"
        android:text="Keliling" />

    <Button
        android:id="@+id/btnproses"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/ejari"
        android:layout_below="@+id/ejari"
        android:layout_marginTop="21dp"
        android:onClick="myClickHandler"
        android:text="Proses" />

    <EditText
        android:id="@+id/eluas"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/btnproses"
        android:layout_centerVertical="true"
        android:ems="10" />

    <EditText
        android:id="@+id/ekeliling"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/eluas"
        android:layout_below="@+id/eluas"
        android:layout_marginTop="29dp"
        android:ems="10" />

</RelativeLayout>

MainActivity.java

package com.example.circlecalculate;

import androidx.appcompat.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 {

    EditText eJari, eLuas, eKeliling;

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

    public void myClickHandler(View v){
        eJari = (EditText) findViewById(R.id.ejari);
        eLuas = (EditText) findViewById(R.id.eluas);
        eKeliling = (EditText) findViewById(R.id.ekeliling);
        switch (v.getId()){
            case R.id.btnproses:
                int jari = Integer.parseInt(eJari.getText().toString());


                double luas = 3.14 * jari * jari ;
                double keliling = 2 * 3.14 ;

                eLuas.setText(String.valueOf(luas));
                eKeliling.setText(String.valueOf(keliling));

                break;
            case R.id.btnhapus:
                eJari.setText("");
                eLuas.setText("");
                eKeliling.setText("");

                break;
        }
    }

}