Xamarin.Android RatingBar

A RatingBar is a UI widget that displays a rating from one to five stars. The user may select a rating by taping on a star In this section, you'll create a widget that allows the user to provide a rating, with the RatingBar widget.

Creating a RatingBar

1. Open the Resource/layout/Main.axml file and add the RatingBar element (inside the LinearLayout):

   <RatingBar android:id="@+id/ratingbar"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:numStars="5"
            android:stepSize="1.0"/>
   

   The android:numStars attribute defines how many stars to display for the rating bar. The android:stepSize attribute defines the granularity for each star (for example, a value of 0.5 would allow half-star ratings).

2. To do something when a new rating has been set, add the following code to the end of the OnCreate() method:

   RatingBar ratingbar = FindViewById<RatingBar>(Resource.Id.ratingbar);
   
   ratingbar.RatingBarChange += (o, e) => {
           Toast.MakeText(this, "New Rating: " + ratingbar.Rating.ToString (), ToastLength.Short).Show ();
   };
   

   This captures the RatingBar widget from the layout with FindViewById and then sets an event method then defines the action to perform when the user sets a rating. In this case, a simple Toast message displays the new rating.

3. Run the application.