Android rating bar example

Android ratingbar is a widget which is used to get rating from the user.We can implement ratingbar in android application by simply adding ratingbar to our layout file. In this tutorial we will learn how to implement a ratingbar in android.

1.Creating New Project

1. Create a new project in Android Studio from File -> New Project
2. Fill the required fields like Application name and package name and click Next
3.  Select Basic activity and click Next, and click  Finish Button.A default activity will be created as MainActivity.java with layouts activity_main.xml and content_main.xml

2. Here is the code for your activity_main.xml

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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"
    android:fitsSystemWindows="true"
    tools:context="com.codesfor.ratingbar.MainActivity">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/AppTheme.PopupOverlay" />

    </android.support.design.widget.AppBarLayout>

    <include layout="@layout/content_main" />

</android.support.design.widget.CoordinatorLayout>

2.  following is the code for res/layout/content_main.xml. This is the layout in which ratingbar widget is added.

content_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.codesfor.ratingbar.MainActivity"
    tools:showIn="@layout/activity_main">

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:gravity="center_horizontal"
        android:orientation="vertical">

        <RatingBar
            android:id="@+id/rb_rating"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:rating="2.0"
            android:stepSize="1.0" />

        <TextView
            android:id="@+id/tv_result"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />

    </LinearLayout>

</RelativeLayout>

There is a ratingbar widget which is defined in about layout file. In this example we will see how to get values whenever we click on rating bar. 

5.  Here is the code for MainActivity.java, the code will contain the reference of ratingbar added in the above layout file and it will show how to implement actions while rating is changed.

MainActivity.java

package com.codesfor.ratingbar;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.RatingBar;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    Toolbar toolbar;
    RatingBar rb_rating;
    TextView tv_result;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //method for initialisation
        init();

// code for rating bar onratingbarchangelistener

        rb_rating.setOnRatingBarChangeListener(new RatingBar.OnRatingBarChangeListener() {
            @Override
            public void onRatingChanged(RatingBar ratingBar, float rating, boolean fromUser) {

                tv_result.setText("Selected Rating is : "+Float.toString(rating));

            }
        });

    }

    private void init() {

        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        rb_rating = (RatingBar) findViewById(R.id.rb_rating);
        tv_result = (TextView) findViewById(R.id.tv_result);


    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

Output