Android Rating Bar 증가

.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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=".MainActivity2"
    android:orientation="vertical">

    <RatingBar
        android:id="@+id/ratingBar1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <RatingBar
        android:id="@+id/ratingBar2"
        style="?android:attr/ratingBarStyleSmall"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:numStars="10"
        android:stepSize="1"/>

    <RatingBar
        android:id="@+id/ratingBar3"
        android:rating="1.5"
        style="?android:attr/ratingBarStyleIndicator"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <Button
        android:id="@+id/btnInc"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="증가"/>

    <Button
        android:id="@+id/btnDec"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="감소"/>


</LinearLayout>

 

.java

public class MainActivity2 extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        RatingBar ratingBar1 = findViewById(R.id.ratingBar1);
        RatingBar ratingBar2 = findViewById(R.id.ratingBar2);
        RatingBar ratingBar3 = findViewById(R.id.ratingBar3);

        Button btnInc = findViewById(R.id.btnInc);
        Button btnDec = findViewById(R.id.btnDec);

        btnInc.setOnClickListener(new View.OnClickListener() {          //증가
            @Override
            public void onClick(View view) {
                ratingBar1.setRating(ratingBar1.getRating() + ratingBar1.getStepSize());
                ratingBar2.setRating(ratingBar2.getRating() + ratingBar2.getStepSize());
                ratingBar3.setRating(ratingBar3.getRating() + ratingBar3.getStepSize());
            }
        });

        btnDec.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                ratingBar1.setRating(ratingBar1.getRating() - ratingBar1.getStepSize());
                ratingBar2.setRating(ratingBar2.getRating() - ratingBar2.getStepSize());
                ratingBar3.setRating(ratingBar3.getRating() - ratingBar3.getStepSize());
            }
        });

    }
}

---

결과 값