Android–ListView滚动条样式

当ListView的记录超过4页时才会显示滑块

java代码：

package com.example.test0123;

import java.lang.reflect.Field;
import android.app.Activity;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class TestList extends Activity {
 ListView lv;

 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.list);
  lv = (ListView) findViewById(R.id.listView1);
  lv.setAdapter(new ListAdapter());

  try {
   Field f = AbsListView.class.getDeclaredField(“mFastScroller”);
   f.setAccessible(true);
   Object o = f.get(lv);
   f = f.getType().getDeclaredField(“mThumbDrawable”);
   f.setAccessible(true);
   Drawable drawable = (Drawable) f.get(o);
   drawable = getResources().getDrawable(R.drawable.ic_launcher);
   f.set(o, drawable);
  } catch (Exception e) {
   throw new RuntimeException(e);
  }

 }

 public class ListAdapter extends BaseAdapter {

  public int getCount() {
   return 200;
  }

  public Object getItem(int position) {
   return null;
  }

  public long getItemId(int position) {
   return 0;
  }

  public View getView(int position, View convertView, ViewGroup parent)