利用反射修改ListView的ScollBar图标

MainActivity如下:

package cc.testlistviewscollbar;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import android.os.Bundle;
import android.widget.AbsListView;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.app.Activity;
import android.graphics.drawable.Drawable;
/**
 * Demo描述:
 * 利用反射修改ListView的ScollBar图标
 *
 * 注意事项:
 * 并不是说这么做就一定会有效果.
 * 只有当ListView要显示的数据足够多(比如四屏或更多)时才会起到作用.
 *
 * 参考资料:
 * 1 http://blog.csdn.net/java2009cgh/article/details/7301197
 * 2 http://blog.csdn.net/lfdfhl/article/details/10311505
 *   Thank you very much
 *
 */
public class MainActivity extends Activity {
	private ListView mListView;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		init();
		setFastScrollBarForListView();
	}

	private void init(){
		mListView=(ListView) findViewById(R.id.listview);
        List<HashMap<String, Object>> list=new ArrayList<HashMap<String,Object>>();
      	HashMap<String, Object> hashMap=null;
      	for (int i = 0; i < 100; i++) {
      		hashMap=new HashMap<String, Object>();
      		hashMap.put("name", "小明"+i);
          	hashMap.put("phone", "135"+i);
          	hashMap.put("amount","500"+i);
        	list.add(hashMap);
		}
      SimpleAdapter adapter=new SimpleAdapter(this, list, R.layout.listviewitem,
      new String []{"name","phone","amount"}, new int[]{R.id.name,R.id.phone,R.id.amount});
      mListView.setAdapter(adapter);
	}

	//修改ListView的FastScroller图标
	private void setFastScrollBarForListView() {
        try {
            Field field = AbsListView.class.getDeclaredField("mFastScroller");
            field.setAccessible(true);
            Object object = field.get(mListView);
            field = field.getType().getDeclaredField("mThumbDrawable");
            field.setAccessible(true);
            Drawable drawable = (Drawable) field.get(object);
            drawable = getResources().getDrawable(R.drawable.ic_launcher);
            field.set(object, drawable);
        } catch (Exception e) {
        	System.out.println("----> 异常信息:"+e.toString());
            e.printStackTrace();
        }

    }

}

main.xml如下:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <ListView
        android:id="@+id/listview"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_centerInParent="true"
        android:fastScrollEnabled="true"
        android:focusable="true" />

</RelativeLayout>

listviewitem如下:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="50dip"
    android:gravity="center"
    android:orientation="horizontal" >

    <TextView
        android:id="@+id/name"
        android:layout_width="100dip"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/phone"
        android:layout_width="150dip"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/amount"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

</LinearLayout>