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1 package com.example.androidseekbar; 2  3 import android.os.Bundle; 4 import android.app.Activity; 5 import android.view.Menu; 6 import android.widget.ImageView; 7 import android.widget.RatingBar; 8 import android.widget.RatingBar.OnRatingBarChangeListener; 9 import android.widget.SeekBar;10 import android.widget.SeekBar.OnSeekBarChangeListener;11 12 public class AndroidSeekBarActivity extends Activity {13 14     @Override15     protected void onCreate(Bundle savedInstanceState) {16         super.onCreate(savedInstanceState);17         setContentView(R.layout.activity_android_seek_bar);18 19         final ImageView img = (ImageView) this.findViewById(R.id.img);20         SeekBar sekbar = (SeekBar) this.findViewById(R.id.sekbar);21         sekbar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {22 23             @Override24             public void onStopTrackingTouch(SeekBar seekBar) {25                 // TODO Auto-generated method stub26 27             }28 29             @Override30             public void onStartTrackingTouch(SeekBar seekBar) {31                 // TODO Auto-generated method stub32 33             }34 35             @Override36             public void onProgressChanged(SeekBar seekBar, int progress,37                     boolean fromUser) {38                 // 拖动时触发39                 img.setAlpha(progress);40             }41         });42         43         RatingBar ratbar=(RatingBar)this.findViewById(R.id.ratbar);44         ratbar.setOnRatingBarChangeListener(new OnRatingBarChangeListener() {45             46             @Override47             public void onRatingChanged(RatingBar arg0, float rating, boolean arg2) {48                 //动态改变图片透明度49                 img.setAlpha((int)(rating*255/5));50             }51         });52     }53 54     @Override55     public boolean onCreateOptionsMenu(Menu menu) {56         // Inflate the menu; this adds items to the action bar if it is present.57         getMenuInflater().inflate(R.menu.activity_android_seek_bar, menu);58         return true;59     }60 61 }