Android SDK Tutorial: Rating Bar Example

In today’s Android SDK tutorial I will show you how to use the rating bar widget.

The Result

Let’s make a widget that displays in text the number of stars you selected from a rating. Like always be sure to change your android:minSdkVersion to a corresponding version.

Android rating bar with 3 stars selected

Motorola Xoom: Android rating bar, 3 stars selected

Now if we touch on another star:

android star rating bar

Android star rating, 7 stars selected

The Manifest (AndroidManifest.xml)

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.example.helloandroid"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="13" />

    <application android:icon="@drawable/icon" android:label="@string/app_name" android:debuggable="true">
    
        <activity android:name=".HelloAndroid"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>
</manifest>

The Layout (main.xml)

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout	
	xmlns:android="http://schemas.android.com/apk/res/android"
	android:layout_width="fill_parent"
	android:layout_height="fill_parent">
	<TextView android:id="@+id/ratingText" android:layout_width="wrap_content" android:layout_height="wrap_content" />
	<RatingBar android:id="@+id/rating" 
		android:isIndicator="false"
		android:stepSize="1.0" 
		android:numStars="10" 
		android:rating="0.0" 
		android:layout_width="wrap_content" 
		android:layout_height="wrap_content">
	</RatingBar>
	
</LinearLayout>

The Rating Bar Java Class(HelloAndroid.java)

package com.example.helloandroid;

import android.app.Activity;
import android.os.Bundle;
import android.widget.RatingBar;
import android.widget.TextView;


public class HelloAndroid extends Activity implements RatingBar.OnRatingBarChangeListener{
	
	RatingBar rating; // declare RatingBar object
	TextView ratingText;// declare TextView Object
	
	@Override
	public void onCreate(Bundle savedInstanceState){
		super.onCreate(savedInstanceState); // call super class constructor
		
		setContentView(R.layout.main);// set content from main.xml
		ratingText=(TextView)findViewById(R.id.ratingText);// create TextView object
		rating=(RatingBar)findViewById(R.id.rating);// create RatingBar object
		rating.setOnRatingBarChangeListener(this);// select listener to be HelloAndroid (this) class
	}
	
	// implement abstract method onRatingChanged
	public void onRatingChanged(RatingBar ratingBar,float rating, boolean fromUser){
		ratingText.setText(""+this.rating.getRating()); // display rating as number in TextView, use "this.rating" to not confuse with "float rating"
	}
}

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