Android SeekBar实现滑动条效果

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
  android:orientation="vertical" android:layout_width="fill_parent" 
  android:layout_height="fill_parent"> 
  <SeekBar android:id="@+id/SeekBar01" android:layout_width="245px" 
    android:layout_height="25px" android:paddingLeft="16px" 
    android:paddingRight="15px" android:paddingTop="5px" 
    android:paddingBottom="5px" android:progress="0" android:max="0" 
    android:secondaryProgress="0" /> 
  <TextView android:layout_width="fill_parent" 
    android:layout_height="wrap_content" android:text="@string/hello" 
    android:id="@+id/TextView01" /> 
</LinearLayout> 

package com.esri.arcgis.sample; 
 
import android.app.Activity; 
import android.os.Bundle; 
import android.widget.SeekBar; 
import android.widget.SeekBar.OnSeekBarChangeListener; 
import android.widget.TextView; 
import android.widget.Toast; 
 
public class AndroidSeekBar extends Activity { 
  /** Called when the activity is first created. */ 
  @Override 
  public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 
 
    // 找到拖动条和文本框 
    final SeekBar sb = (SeekBar) findViewById(R.id.SeekBar01); 
    final TextView tv1 = (TextView) findViewById(R.id.TextView01); 
 
    // 设置拖动条的初始值和文本框的初始值 
    sb.setMax(100); 
    sb.setProgress(30); 
    tv1.setText("当前进度：" + sb.getProgress()); 
 
    // 设置拖动条改变监听器 
    OnSeekBarChangeListener osbcl = new OnSeekBarChangeListener() { 
 
      @Override 
      public void onProgressChanged(SeekBar seekBar, int progress, 
          boolean fromUser) { 
        tv1.setText("当前进度：" + sb.getProgress()); 
        Toast.makeText(getApplicationContext(), "onProgressChanged", 
            Toast.LENGTH_SHORT).show(); 
      } 
 
      @Override 
      public void onStartTrackingTouch(SeekBar seekBar) { 
        Toast.makeText(getApplicationContext(), "onStartTrackingTouch", 
            Toast.LENGTH_SHORT).show(); 
      } 
 
      @Override 
      public void onStopTrackingTouch(SeekBar seekBar) { 
        Toast.makeText(getApplicationContext(), "onStopTrackingTouch", 
            Toast.LENGTH_SHORT).show(); 
      } 
 
    }; 
 
    // 为拖动条绑定监听器 
    sb.setOnSeekBarChangeListener(osbcl); 
 
  } 
}