Source Code Program Penghitung Luas Persegi Panjang di Android

Kali ini saya akan berbagi source code android ,program ini suangat sederhana. Saya rasa program seperti ini bagi programer android pemula pasti sangat berguna.

Ok , tampilan program seperti gambar dibawah ini.

Source code tampilan (activity_main.xml)

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
 android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
 android:paddingRight="@dimen/activity_horizontal_margin"
 android:paddingTop="@dimen/activity_vertical_margin"
 android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

 <Button
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="Hitung"
 android:id="@+id/button"
 android:layout_marginTop="51dp"
 android:layout_below="@+id/editTextLebar"
 android:layout_alignParentRight="true"
 android:layout_alignParentEnd="true" />

 <TextView
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="Panjang :"
 android:id="@+id/textViewPanjang"
 android:layout_alignRight="@+id/button"
 android:layout_alignEnd="@+id/button"
 android:layout_marginTop="27dp"
 android:layout_alignParentLeft="true"
 android:layout_alignParentStart="true" />

 <TextView
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="Lebar :"
 android:id="@+id/textViewLebar"
 android:layout_below="@+id/textViewPanjang"
 android:layout_alignParentLeft="true"
 android:layout_alignParentStart="true"
 android:layout_marginTop="25dp" />

 <EditText
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:id="@+id/editTextPanjang"
 android:layout_above="@+id/textViewLebar"
 android:layout_alignParentRight="true"
 android:layout_alignParentEnd="true"
 android:layout_toRightOf="@+id/textView"
 android:layout_toEndOf="@+id/textView"
 android:inputType="number|numberDecimal"
 android:numeric="decimal" />

 <EditText
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:id="@+id/editTextLebar"
 android:layout_alignBottom="@+id/textViewLebar"
 android:layout_alignLeft="@+id/editTextPanjang"
 android:layout_alignStart="@+id/editTextPanjang"
 android:layout_alignRight="@+id/editTextPanjang"
 android:layout_alignEnd="@+id/editTextPanjang"
 android:inputType="number|numberDecimal"
 android:numeric="decimal" />

 <TextView
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="Hasil Luas :"
 android:id="@+id/textView"
 android:layout_below="@+id/textViewLebar"
 android:layout_alignParentLeft="true"
 android:layout_alignParentStart="true"
 android:layout_marginTop="27dp" />

 <EditText
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:id="@+id/editTextLuas"
 android:layout_alignBottom="@+id/textView"
 android:layout_alignLeft="@+id/editTextLebar"
 android:layout_alignStart="@+id/editTextLebar"
 android:layout_alignRight="@+id/editTextLebar"
 android:layout_alignEnd="@+id/editTextLebar"
 android:inputType="numberDecimal"
 android:editable="false"
 />

</RelativeLayout>

Source code entity persegipanjang (PersegiPanjang.java)

package com.example.andiksetyawan.persegipanjang.entity;

/**
* Created by AndikSetyawan on 3/22/2015.
*/
public class PersegiPanjang {
private double panjang;
private double lebar;
private double luas;

public double getLuas() {
return luas = panjang*lebar;
}

public double getPanjang() {
return panjang;
}

public void setPanjang(double panjang) {
this.panjang = panjang;
}

public double getLebar() {
return lebar;
}

public void setLebar(double lebar) {
this.lebar = lebar;
}
}

Source Code activity (MainActivity.java)

package com.example.andiksetyawan.persegipanjang;

import android.content.Context;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.example.andiksetyawan.persegipanjang.entity.PersegiPanjang;

public class MainActivity extends ActionBarActivity {
 private EditText txtP;
 private EditText txtL;
 private EditText txtLuas;
 private Button button;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 button = (Button) findViewById(R.id.button);
 txtP = (EditText) findViewById(R.id.editTextPanjang);
 txtL = (EditText) findViewById(R.id.editTextLebar);
 txtLuas = (EditText) findViewById(R.id.editTextLuas);
 button.setOnClickListener(new View.OnClickListener() {
 public void onClick(View arg0) {
 String p,l;
 p = txtP.getText().toString();
 l = txtL.getText().toString();
 final PersegiPanjang persegiPanjang = new PersegiPanjang();
 Context context = getApplicationContext();
 if (p.matches("")){
 txtP.requestFocus();
 Toast.makeText(context, "Kamu belum memasukkan inputan panjang", Toast.LENGTH_SHORT).show();
 }else if(l.matches("")){
 txtL.requestFocus();
 Toast.makeText(context, "Kamu belum memasukkan inputan lebar", Toast.LENGTH_SHORT).show();
 }else{
 persegiPanjang.setPanjang(Double.parseDouble(p));
 persegiPanjang.setLebar(Double.parseDouble(l));

 txtLuas.setText(String.valueOf(persegiPanjang.getLuas()));
 }
 }
 });
 }
 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
 // Inflate the menu; this adds items to the action bar if it is present.
 getMenuInflater().inflate(R.menu.menu_main, menu);
 return true;
 }

 @Override
 public boolean onOptionsItemSelected(MenuItem item) {
 // Handle action bar item clicks here. The action bar will
 // automatically handle clicks on the Home/Up button, so long
 // as you specify a parent activity in AndroidManifest.xml.
 int id = item.getItemId();

 //noinspection SimplifiableIfStatement
 if (id == R.id.action_settings) {
 return true;
 }

 return super.onOptionsItemSelected(item);
 }
}

Lebih mudahnya silahkan project diatas dibawah ini:
[download] => via mediafire, size 5MB, Android Studio Project.