ListView 和 Adapter 的基础2

来源：互联网发布：股票模拟软件编辑：程序博客网时间：2024/05/21 23:26

不同的项目布局(item layout)

我们再举一个稍微复杂的例子，在上例的list中加入一些分隔线

你需要做这些:

重(@Override)写 getViewTypeCount() – 返回你有多少个不同的布局
重写 getItemViewType(int) – 由position返回view type id
根据view item的类型，在getView中创建正确的convertView

以下是代码：

public class MultipleItemsList extends ListActivity {      private MyCustomAdapter mAdapter;      @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        mAdapter = new MyCustomAdapter();        for (int i = 1; i < 50; i++) {            mAdapter.addItem("item " + i);            if (i % 4 == 0) {                mAdapter.addSeparatorItem("separator " + i);            }        }        setListAdapter(mAdapter);    }      private class MyCustomAdapter extends BaseAdapter {          private static final int TYPE_ITEM = 0;        private static final int TYPE_SEPARATOR = 1;        private static final int TYPE_MAX_COUNT = TYPE_SEPARATOR + 1;          private ArrayList mData = new ArrayList();        private LayoutInflater mInflater;          private TreeSet mSeparatorsSet = new TreeSet();          public MyCustomAdapter() {            mInflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);        }          public void addItem(final String item) {            mData.add(item);            notifyDataSetChanged();        }          public void addSeparatorItem(final String item) {            mData.add(item);            // save separator position            mSeparatorsSet.add(mData.size() - 1);            notifyDataSetChanged();        }          @Override        public int getItemViewType(int position) {            return mSeparatorsSet.contains(position) ? TYPE_SEPARATOR : TYPE_ITEM;        }          @Override        public int getViewTypeCount() {            return TYPE_MAX_COUNT;        }          @Override        public int getCount() {            return mData.size();        }          @Override        public String getItem(int position) {            return mData.get(position);        }          @Override        public long getItemId(int position) {            return position;        }          @Override        public View getView(int position, View convertView, ViewGroup parent) {            ViewHolder holder = null;            int type = getItemViewType(position);            System.out.println("getView " + position + " " + convertView + " type = " + type);            if (convertView == null) {                holder = new ViewHolder();                switch (type) {                    case TYPE_ITEM:                        convertView = mInflater.inflate(R.layout.item1, null);                        holder.textView = (TextView)convertView.findViewById(R.id.text);                        break;                    case TYPE_SEPARATOR:                        convertView = mInflater.inflate(R.layout.item2, null);                        holder.textView = (TextView)convertView.findViewById(R.id.textSeparator);                        break;                }                convertView.setTag(holder);            } else {                holder = (ViewHolder)convertView.getTag();            }            holder.textView.setText(mData.get(position));            return convertView;        }      }      public static class ViewHolder {        public TextView textView;    }}

运行程序，你会看到每4个item一个分割线：