Teknologiskolen

Android Studio plus og minus

package teknologiskolen.com.additionsubstraction;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    private Button btnPlus;
    private Button btnMinus;

    private TextView txtBalance;

    private int balance;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        // Initialisering af knapper
        btnPlus = (Button)findViewById(R.id.btnPlus);
        btnMinus = (Button)findViewById(R.id.btnMinus);

        // Initialisering af tekstfelt
        txtBalance = (TextView)findViewById(R.id.txtBalance);

        // Sæt værdien af balance variablen
        balance = 1000000;

        // Sæt balancen til at være synlig på textviewet
        txtBalance.setText(balance + "");

        // Giver knapperne en "lytter" - altså sådan de kan gøre noget
        btnPlus.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                balance++;
                txtBalance.setText(balance + "");
            }
        });

        btnMinus.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                balance--;
                txtBalance.setText(balance + "");
            }
        });
    }

    @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);
    }
}