拖动条SeekBar及星级评分条

1.布局

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".AndroidSeekBarActivity" >

    <ImageView
        android:id="@+id/img"
        android:layout_width="match_parent"
        android:layout_height="240px"
        android:src="@drawable/mm" />

    <SeekBar
        android:id="@+id/sekbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:max="255"
        android:progress="255"
        android:thumb="@drawable/sj" />

    <RatingBar
        android:id="@+id/ratbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:max="255"
        android:numStars="5"
        android:progress="255"
        android:stepSize="0.5" />

</LinearLayout>

2.逻辑控制

package com.example.androidseekbar;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.ImageView;
import android.widget.RatingBar;
import android.widget.RatingBar.OnRatingBarChangeListener;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;

public class AndroidSeekBarActivity extends Activity {

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

        final ImageView img = (ImageView) this.findViewById(R.id.img);
        SeekBar sekbar = (SeekBar) this.findViewById(R.id.sekbar);
        sekbar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                // TODO Auto-generated method stub

            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
                // TODO Auto-generated method stub

            }

            @Override
            public void onProgressChanged(SeekBar seekBar, int progress,
                    boolean fromUser) {
                // 拖动时触发
                img.setAlpha(progress);
            }
        });
        
        RatingBar ratbar=(RatingBar)this.findViewById(R.id.ratbar);
        ratbar.setOnRatingBarChangeListener(new OnRatingBarChangeListener() {
            
            @Override
            public void onRatingChanged(RatingBar arg0, float rating, boolean arg2) {
                //动态改变图片透明度
                img.setAlpha((int)(rating*255/5));
            }
        });
    }

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

}