Menghitung Luas Lingkaran

Posted by WIDIA NINGSIH on November 18, 2017 in

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:id="@+id/LinearLayout2"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical"

    android:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context=".HitungLuas" >

    <TextView

        android:id="@+id/txtJari"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="@string/txtNilaiJari" />

    <EditText

        android:id="@+id/edtNilaiJari"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:ems="10"

        android:inputType="numberDecimal" >

        <requestFocus />

    </EditText>

    <Button

        android:id="@+id/btnHitung"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="@string/txtHitung" />

    <TextView

        android:id="@+id/txtLuas"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="@string/txtLuas"

        android:textAppearance="?android:attr/textAppearanceLarge" />

</LinearLayout>

package com.widianingsih.luaslingkarann;

import android.os.Bundle;

import android.app.Activity;

import android.view.Menu;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

import android.widget.TextView;

public class HitungLuas extends Activity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_hitung_luas);

        final EditText edtNilaiJari=(EditText) findViewById(R.id.edtNilaiJari);

        final Button btnHitung=(Button) findViewById(R.id.btnHitung);

        final TextView txtLuas = (TextView) findViewById(R.id.txtLuas);

        btnHitung.setOnClickListener(new View.OnClickListener() {

                                                @Override

                                                public void onClick(View arg0) {

                                                                // TODO Auto-generated method stub

                                                                int valNilaiJari= Integer.parseInt(edtNilaiJari.getText().toString());

                                                                int luas=(int) (3.14*valNilaiJari*valNilaiJari);

                 txtLuas.setText("Luas= "+luas);

                                                               

                                                }

                                });

    }

    @Override

    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.

        getMenuInflater().inflate(R.menu.hitung_luas, menu);

        return true;

    }

   

}