Android 自定义滑动条

Java代码如下:

滑动条  //
LayoutInflater myInflater = LayoutInflater.from(this);
seekBar = (SeekBar)myInflater.inflate(R.layout.seekbar, null).findViewById(R.id.seekbar);
seekBar.setBackgroundResource(R.drawable.music_back);//设置滑动条的背景,不知道为什么,在XML里面设置背景一直显示不正常,只拉升显示了一部分
Bitmap bitmapSeekBack = BitmapFactory.decodeResource(getResources(),R.drawable.music_back);
//确定这个控件的大小和位置
left = 151*ndisplayWidth/main.nDefaultWidth;
top = 110*ndisplayHeight/main.nDefaultHeigh;
width = bitmapSeekBack.getWidth();
height = bitmapSeekBack.getHeight();
lpParam = new AbsoluteLayout.LayoutParams(width,height,left,top);
abslayout.addView(seekBar, lpParam); 
seekBar.setonSeekBarchangelistener(new OnMusicSeekBarChange());
 
class OnMusicSeekBarChange implements OnSeekBarchangelistener
{
 public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser)
 {
 }
 public void onStartTrackingTouch(SeekBar seekBar)
 {
 }
 public void onStopTrackingTouch(SeekBar seekBar)
 {
  mPlayer.seekTo(mPlayer.getDuration()*seekBar.getProgress()/seekBar.getMax());
 }
}

layout目录下的seekbar.xml

<?xml version="1.0" encoding="utf-8"?>
 <SeekBar xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/seekbar"
  android:progressDrawable="@drawable/seekbar"  
  android:thumb="@drawable/thumb"
 /> 

drawable目录下的seekbar.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:id="@android:id/progress">    
         <clip android:drawable="@drawable/music_fore" />
    </item>
</layer-list> 

drawable目录下的thumb.xml

<?xml version="1.0" encoding="UTF-8"?>  
<selector xmlns:android="http://schemas.android.com/apk/res/android">        
 <!-- 按下状态-->
 <item
  android:state_pressed="true"
  android:drawable="@drawable/playerslider_down"
 />
  
 <!-- 松开状态 -->
 <item
  android:state_pressed="false"
  android:drawable="@drawable/playerslider_up" 
 />
</selector>