通过星级改变图片的透明度

来源：互联网发布：淘宝宝贝收藏在哪里编辑：程序博客网时间：2024/04/27 14:34

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:orientation="vertical"    android:layout_width="match_parent"    android:layout_height="match_parent"     ><ImageView     android:id="@+id/imageview"    android:layout_width="match_parent"    android:layout_height="320dp"    android:src="@drawable/lijiang"/>    <RatingBar        android:id="@+id/ratingbar"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:numStars="5"        android:max="255"        android:progress="255"        android:stepSize="0.5" /></LinearLayout>

MainActivity.java

<pre name="code" class="java">package com.lxm.ratingbartest;import android.app.Activity;import android.os.Bundle;import android.view.Menu;import android.widget.ImageView;import android.widget.RatingBar;import android.widget.RatingBar.OnRatingBarChangeListener;public class MainActivity extends Activity {RatingBar ratingbar;ImageView image;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);image = (ImageView) findViewById(R.id.imageview);ratingbar = (RatingBar) findViewById(R.id.ratingbar);ratingbar.setOnRatingBarChangeListener(new OnRatingBarChangeListener() {@Overridepublic void onRatingChanged(RatingBar ratingBar, float rating,boolean fromUser) {image.setAlpha((int)(rating*25/5));}});}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}}

运行效果：

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