XML属性

1.android:isIndicator 是否允许改变，true为步允许
2.android:numStars 星星总数
3.android:rating 默认星级
4.android:stepSize 每一次改变的星星数

常用方法

getRating(); 获取等级
getStepSize(); 每次改变多少个星星
getProgress(); 获取进度值，进度值为=星星等级*每次改变的星星数

例子

<RatingBar
    android:isIndicator="false"
    android:numStars="5"
    android:rating="3.5"
    android:id="@+id/ratingBar"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />
<Button
    android:layout_below="@+id/ratingBar"
    android:id="@+id/bn"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
   android:text="提交" />

public class MainActivity extends AppCompatActivity {
    private RatingBar ratingBar;
    private Button bn;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main); 
        ratingBar = (RatingBar) findViewById(R.id.ratingBar);
        bn = (Button) findViewById(R.id.bn);
        bn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                int result = ratingBar.getProgress();
                float raing = ratingBar.getRating();
                float step = ratingBar.getStepSize();
                Log.i("星级评分","'进度值："+result+"默认星："+raing+"每一步多少："+step);
                Toast.makeText(MainActivity.this, "您获得了"+raing+"颗星星", Toast.LENGTH_SHORT).show();
            }
        });
    }
}