<?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="com.example.blogtest.MainActivity"> 
  <!--numStars设置星星的数量，stepSize默认的评分--> 
  <RatingBar 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:id="@+id/rb_main_rating" 
    android:numStars="5" 
    android:stepSize="0.5" 
    /> 
</LinearLayout> 

package com.example.blogtest; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.view.Gravity; 
import android.widget.RatingBar; 
import android.widget.Toast; 
public class MainActivity extends AppCompatActivity { 
  private RatingBar rb_main_rating; 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    //获得RatingBar的控件 
    rb_main_rating = (RatingBar) findViewById(R.id.rb_main_rating); 
    //给控件设置监听事件 
    rb_main_rating.setOnRatingBarChangeListener(new RatingBar.OnRatingBarChangeListener() { 
      @Override 
      public void onRatingChanged(RatingBar ratingBar, float rating, boolean fromUser) { 
        Toast t=Toast.makeText(MainActivity.this,"您的评分为："+rating,Toast.LENGTH_SHORT); 
        t.setGravity(Gravity.CENTER,0,0); 
        t.show(); 
      } 
    }); 
  } 
}