Coding Membuat Aplikasi Kalkulator di Android (Menggunakan Android Studio)

1. MainActivity.java

package com.example.user.kalkulatormini;

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


public class MainActivity extends AppCompatActivity {
    private double hasilAkhir = 0.0;
    private String angka1 = "";
    private String angka2 = "";
    TextView hasil;
    Button btJumlah, btKurang, btKali, btBagi;
    EditText edAngka1, edAngka2;


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

        edAngka1 = (EditText) findViewById(R.id.editAngka1);
        edAngka2 =  (EditText) findViewById(R.id.editAngka2);
        hasil = (TextView) findViewById(R.id.textHasil);
        btJumlah = (Button) findViewById(R.id.tombolTambah);
        btKurang = (Button) findViewById(R.id.tombolKurang);
        btKali = (Button) findViewById(R.id.tombolKali);
        btBagi = (Button) findViewById(R.id.tombolBagi);

    }

    public void klikTambah (View V){
        angka1 = edAngka1.getText().toString();
        angka2 = edAngka2.getText().toString();

        if (angka1.equalsIgnoreCase("") || (angka2.equalsIgnoreCase(""))){
            edAngka1.setFocusable(true);
        }else{
            double angkaA = Double .parseDouble(angka1);
            double angkaB = Double .parseDouble(angka2);
            hasilAkhir = angkaA + angkaB;
            String hasilString = String .valueOf(hasilAkhir);
            hasil.setText (hasilString);

        }

    }

    public void klikKurang (View V){
        angka1 = edAngka1.getText().toString();
        angka2 = edAngka2.getText().toString();

        if (angka1.equalsIgnoreCase("") || (angka2.equalsIgnoreCase(""))){
            edAngka1.setFocusable(true);
        }else{
            double angkaA = Double .parseDouble(angka1);
            double angkaB = Double .parseDouble(angka2);
            hasilAkhir = angkaA - angkaB;
            String hasilString = String .valueOf(hasilAkhir);
            hasil.setText (hasilString);

        }

    }

    public void klikKali (View V){
        angka1 = edAngka1.getText().toString();
        angka2 = edAngka2.getText().toString();

        if (angka1.equalsIgnoreCase("") || (angka2.equalsIgnoreCase(""))){
            edAngka1.setFocusable(true);
        }else{
            double angkaA = Double .parseDouble(angka1);
            double angkaB = Double .parseDouble(angka2);
            hasilAkhir = angkaA * angkaB;
            String hasilString = String .valueOf(hasilAkhir);
            hasil.setText (hasilString);

        }

    }

    public void klikBagi (View V){
        angka1 = edAngka1.getText().toString();
        angka2 = edAngka2.getText().toString();

        if (angka1.equalsIgnoreCase("") || (angka2.equalsIgnoreCase(""))){
            edAngka1.setFocusable(true);
        }else{
            double angkaA = Double .parseDouble(angka1);
            double angkaB = Double .parseDouble(angka2);
            hasilAkhir = angkaA / angkaB;
            String hasilString = String .valueOf(hasilAkhir);
            hasil.setText (hasilString);

        }

    }

    @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) {
     
        int id = item.getItemId();

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

        return super.onOptionsItemSelected(item);
    }
}

Share on Facebook

Share on Twitter

Share on Google+

Share on LinkedIn