/*此时，所有的Object对象都没有被释放，因为变量v引用这些对象。实际上这些对象已经是无用的，但还被引用，GC就无能为力了(事实上GC认为它还有用)，这一点是导致内存泄漏最重要的原因。*/
Vector v = new Vector(10);   
for (int i = 1; i < 100; i++)   {   　
  Object o = new Object();   　
  v.add(o);   　
  o = null;   
 }

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

 <?xml version="1.0" encoding="utf-8" ?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="60dip">
 <ImageView android:id="@+id/icon" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:paddingLeft="9px" /> 
 <TextView android:id="@+id/text" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_toRightOf="@id/icon" android:textAppearance="?android:attr/textAppearanceMedium" android:paddingLeft="9px" /> 
 </RelativeLayout>

public class BadAdapter extends BaseAdapter {
  ......

  @Override
  public View getView(int position, View convertView, ViewGroup parent) {
    Log.d("MyAdapter", "Position:" + position + "---"
        + String.valueOf(System.currentTimeMillis()));
    final LayoutInflater inflater = (LayoutInflater) mContext
        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View v = inflater.inflate(R.layout.list_item_icon_text, null);
    ((ImageView) v.findViewById(R.id.icon)).setImageResource(R.drawable.icon);
    ((TextView) v.findViewById(R.id.text)).setText(mData[position]);
    return v;
  }
}

public class GoodAdapter extends BaseAdapter {

  ......

  @Override
  public View getView(int position, View convertView, ViewGroup parent) {
    Log.d("MyAdapter", "Position:" + position + "---"
        + String.valueOf(System.currentTimeMillis()));
    ViewHolder holder;
    if (convertView == null) {
      final LayoutInflater inflater = (LayoutInflater) mContext
          .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
      convertView = inflater.inflate(R.layout.list_item_icon_text, null);
      holder = new ViewHolder();
      holder.icon = (ImageView) convertView.findViewById(R.id.icon);
      holder.text = (TextView) convertView.findViewById(R.id.text);
      convertView.setTag(holder);
    } else {
      holder = (ViewHolder) convertView.getTag();
    }
    holder.icon.setImageResource(R.drawable.icon);
    holder.text.setText(mData[position]);
    return convertView;
  }

  static class ViewHolder {
    ImageView icon;
    TextView text;
  }
}

public class MainActivity extends ListActivity {
  private BadAdapter/GoodAdapter mAdapter;

  private String[] mArrData;

  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    mArrData = new String[1000];
    for (int i = 0; i < 1000; i++) {
      mArrData[i] = "Google IO Adapter";
    }
    mAdapter = new BadAdapter/GoodAdapter(this, mArrData);
    setListAdapter(mAdapter);
  }
}