Android中SeekBar拖动条使用方法详解

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
 android:orientation="vertical"
 tools:context=".SeekBarActivity">
 
 <ImageView
  android:id="@+id/image"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:src="@drawable/pineapple" />
 
 
 <!--android:thumb 自定义一个Drawable对象（设置滑块的小图标）-->
 <SeekBar
  android:id="@+id/seekbar"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:max="250"
  android:progress="150"
  android:thumb="@drawable/test" />
</LinearLayout>

public class SeekBarActivity extends AppCompatActivity {
 private ImageView imageView;//图片
 private SeekBar seekBar;//拖动条
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_seek_bar);
 
  imageView = (ImageView)findViewById(R.id.image);
  seekBar = (SeekBar)findViewById(R.id.seekbar);
 
  seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {、
   //滑块位置变动时触发该方法
   @Override
   public void onProgressChanged(SeekBar seekBar, int progress, boolean b) {
    //设置图片透明度
    imageView.setImageAlpha(progress);
   }
 
   @Override
   public void onStartTrackingTouch(SeekBar seekBar) {
 
   }
 
   @Override
   public void onStopTrackingTouch(SeekBar seekBar) {
 
   }
  });
 }
}