分组 布局 adapter

package com.example.listview;


import java.util.ArrayList;
import java.util.HashMap;

import android.app.ListActivity;
import android.content.Context;
import android.graphics.Color;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;


public class MainActivity extends ListActivity {
	
	//item view的类型总数
	private final int VIEW_TYPE_COUNT = 2;
	private final String DATA="data";
	private final String TYPE="type";
	private final int GROUP=-2;
	private final int ITEM=-3;
	
	private ArrayList<HashMap<String,Object>> items = null;
	

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		
		ListView listview = this.getListView();
		BaseAdapter adapter = new MyBaseAdapter();
		
		items = new ArrayList<HashMap<String, Object>>(); 
		listview.setAdapter(adapter);
	
		String [] groups={"A","B","C","D","E","F"};
		int count=0;
		for(int i=0;i<groups.length;i++){
			HashMap<String,Object> group_map = new HashMap<String,Object>();
			group_map.put(TYPE,GROUP);
			group_map.put(DATA, groups[i]);
			items.add(group_map);
		
			for (int j = 0; j < 5; j++) {  
                HashMap<String, Object> data_map = new HashMap<String, Object>();  
                data_map.put(TYPE, ITEM);  
                data_map.put(DATA, "数据:" + (count++));  
                items.add(data_map);  
            }  
		}	
	}
	private class MyBaseAdapter extends BaseAdapter{
	
		private LayoutInflater inflater = null;
		
		public  MyBaseAdapter(){
			inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);	
		}

		@Override
		public int getCount() {
			
			return items.size();
		}

		@Override
		public Object getItem(int position) {
			HashMap<String, Object> map = items.get(position);
			return map.get(DATA); 
		}

		@Override
		public long getItemId(int position) {
			
			return position;
		}

		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			int type = getItemViewType(position);
			
			//根据不同的view type加载不同的布局文件 
			switch(type){
			case GROUP:
				convertView = inflater.inflate(android.R.layout.simple_list_item_2,null);
				
				TextView tv1 = (TextView) convertView.findViewById(android.R.id.text1);
				tv1.setText("分组");
				tv1.setBackgroundColor(Color.RED);
				
				TextView tv2 = (TextView) convertView.findViewById(android.R.id.text2);           
                tv2.setText(getItem(position) + "");  
                tv2.setBackgroundColor(Color.GRAY); 
                break;
			case ITEM:
				convertView = inflater.inflate(  
                        android.R.layout.simple_list_item_1, null);  
                TextView tv = (TextView) convertView  
                        .findViewById(android.R.id.text1);  
                tv.setText(getItem(position) + "");  
                break;  
			}
			return convertView;
		}
		
		//解析view type
		//view type值是我们事先埋入到items数据中的字段值
		//注意：此处的返回值不要大于getViewTypeCount（）的返回值
		@Override
		public int getItemViewType(int position) {
			HashMap<String, Object> map = items.get(position);
			return (Integer) map.get(TYPE);
		}
		
		// 在本例中共计有2个不同类型的view  
        // android.R.layout.simple_list_item_1 和  
        // android.R.layout.simple_list_item_1.
		@Override
		public int getViewTypeCount() {
			
			return VIEW_TYPE_COUNT;  
		}
	}
}