<?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設置星星的數量，stepSize默認的評分-->   <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);     //獲得RatingBar的控件     rb_main_rating = (RatingBar) findViewById(R.id.rb_main_rating);     //給控件設置監聽事件     rb_main_rating.setOnRatingBarChangeListener(new RatingBar.OnRatingBarChangeListener() {       @Override       public void onRatingChanged(RatingBar ratingBar, float rating, boolean fromUser) {         Toast t=Toast.makeText(MainActivity.this,"您的評分為："+rating,Toast.LENGTH_SHORT);         t.setGravity(Gravity.CENTER,0,0);         t.show();       }     });   } }