Android评分条示例

Android RatingBar 可以用来获取用户的评分。评分返回一个浮点数，例如2.0，3.5，4.0等。

Android RatingBar会以星星的形式显示评分。Android RatingBar是AbsSeekBar类的子类。

android RatingBar类的 getRating() 方法会返回评分数字。

Android RatingBar示例

让我们看一个简单的Android评分条示例。

activity_main.xml

从工具箱中拖动RatingBar和Button，现在activity_main.xml文件将如下所示:

<?xml version="1.0" encoding="utf-8"?>  
<android.support.constraint.ConstraintLayout 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="example.javatpoint.com.ratingbar.MainActivity">  

    <Button  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:text="submit"  
        android:id="@+id/button"  
        app:layout_constraintBottom_toBottomOf="parent"  
        app:layout_constraintLeft_toLeftOf="parent"  
        app:layout_constraintRight_toRightOf="parent"  
        app:layout_constraintTop_toTopOf="parent"  
        app:layout_constraintVertical_bias="0.615" />  

    <RatingBar  
        android:id="@+id/ratingBar"  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:layout_marginLeft="72dp"  
        android:layout_marginTop="60dp"  
        app:layout_constraintStart_toStartOf="parent"  
        app:layout_constraintTop_toTopOf="parent" />  

</android.support.constraint.ConstraintLayout>  

Activity类

让我们来编写代码以显示用户的评分。

package example.javatpoint.com.ratingbar;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.RatingBar;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    RatingBar ratingbar;
    Button button;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        addListenerOnButtonClick();
    }
    public void addListenerOnButtonClick(){
        ratingbar=(RatingBar)findViewById(R.id.ratingBar);
        button=(Button)findViewById(R.id.button);
        //Performing action on Button Click
        button.setOnClickListener(new View.OnClickListener(){

            @Override
            public void onClick(View arg0) {
                //Getting the rating and displaying it on the toast
                String rating=String.valueOf(ratingbar.getRating());
                Toast.makeText(getApplicationContext(), rating, Toast.LENGTH_LONG).show();
            }

        });
    }
}

输出：