AsyncTask 异步查询 通讯录

package com.example.asynctasktest;

import java.io.InputStream;
import java.util.ArrayList;

import android.app.Activity;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Color;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.provider.ContactsContract.CommonDataKinds.Phone;
import android.provider.ContactsContract.CommonDataKinds.Photo;
import android.text.TextUtils;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;

/**
 * 当执行的操作比较耗时时候，比如查询通讯录数据库。可以使用AsyncTask 这个类去异步查询
 * ，一边查询数据一边更新数据。 可以读取十条联系人，更新一次画面。不用等到全部查询结束再去更新画面。
 * 不要忘记在AndroidManifest中添加读取联系人的权限
 *    
	
 * */
public class ContactView extends Activity
{

	ContentResolver resolver;
	Cursor phoneCursor;
	
	//定义一个异步查询数据库的任务
	AsynLoadcontactTask task;
	
	private Context mContext = null;
	private MyListAdapter myAdapter = null;
	
	//查询联系人数据库里的字段
    private static final String[] PHONES_PROJECTION = new String[] {
    	Phone.DISPLAY_NAME, 
    	Phone.NUMBER, 
    	Photo.PHOTO_ID,
    	Phone.CONTACT_ID
    	};
   
    private static final int PHONES_DISPLAY_NAME_INDEX = 0;
    
    private static final int PHONES_NUMBER_INDEX = 1;
    
    private static final int PHONES_PHOTO_ID_INDEX = 2;
   
    private static final int PHONES_CONTACT_ID_INDEX = 3;
    //存放联系人的名字
    private ArrayList mContactsName = new ArrayList();
    //存放联系人的号码
    private ArrayList mContactsNumber = new ArrayList();
    //存放联系人的头像，手机中存储的联系人可以有头像，sim卡中一律没有头像
    private ArrayList mContactsPhonto = new ArrayList();
    //存放联系人头像的地址
    private ArrayList mContactsPhontoUri = new ArrayList();

    //定义一个listview
	private ListView listView = null;
	
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		
		listView = new ListView(this);
		setContentView(listView);
		
		mContext = this;
		listView.setBackgroundColor(Color.WHITE);
		
		myAdapter = new MyListAdapter(mContext);
		
		task = new AsynLoadcontactTask();
		
		//异步查询数据库 开始执行
		task.execute(0);
	}
	
	@Override
	public void onBackPressed() {
		//取消异步查询
		task.cancel(true);
		super.onBackPressed();
	}
	@Override
	protected void onResume() {
		super.onResume();
		
		listView.setOnItemClickListener(new OnItemClickListener() {
			
			public void onItemClick(AdapterView arg0, View arg1, int arg2,
					long arg3) {
				// TODO Auto-generated method stub
				Log.i("xxx", "you clicked item "+arg2);
			}
		});
		
		listView.setAdapter(myAdapter);
	}
    	
	//定义一个ViewHolder
	private static class ViewHolder {

		ImageView image = null;
		TextView name = null;
		TextView number = null;
	}
	
	//adapter 填充listview
    class MyListAdapter extends BaseAdapter {
    	
		public MyListAdapter(Context context) {
		    mContext = context;
		}
	
		public int getCount() {
		    return mContactsName.size();
		}
	
		@Override
		public boolean areAllItemsEnabled() {
		    return false;
		}
	
		public Object getItem(int position) {
		    return position;
		}
	
		public long getItemId(int position) {
		    return position;
		}
	
		public View getView(int position, View convertView, ViewGroup parent) {
			ViewHolder viewHolder = null;
			
			if (convertView == null) {
				convertView = LayoutInflater.from(mContext).inflate(
						R.layout.contactor, null);
				viewHolder = new ViewHolder();
				viewHolder.image = (ImageView) convertView
						.findViewById(R.id.head_icon);
				viewHolder.name = (TextView) convertView
						.findViewById(R.id.name);
				viewHolder.number = (TextView) convertView
						.findViewById(R.id.number);

				convertView.setTag(viewHolder);
			} else {
				viewHolder = (ViewHolder) convertView.getTag();
			}
		    viewHolder.name.setText(mContactsName.get(position));
		    viewHolder.number.setText(mContactsNumber.get(position));
		    viewHolder.image.setImageBitmap(mContactsPhonto.get(position));
		    return convertView;
		}

    }
    
    //AsyncTask 查询数据库 边查边去填充ListView， 查询10条联系人 更新一次ListView里的数据。
	private class AsynLoadcontactTask extends AsyncTask {
		
		private AsynLoadcontactTask(){
		}

		
		@Override
		protected void onPostExecute(Integer result) {
			// TODO Auto-generated method stub
			super.onPostExecute(result);
			phoneCursor.close();
			
		}
		
		protected synchronized Integer doInBackground(Integer... params) {
	    	mContactsName.clear();
			mContactsNumber.clear();
			mContactsPhonto.clear();
			mContactsPhontoUri.clear();
			
			resolver = mContext.getContentResolver();
			phoneCursor = resolver.query(Phone.CONTENT_URI,PHONES_PROJECTION, null, null, null);
		
			if (phoneCursor != null) {
				
			    while (phoneCursor.moveToNext()) {
		
					String phoneNumber = phoneCursor.getString(PHONES_NUMBER_INDEX);
					if (TextUtils.isEmpty(phoneNumber))
					    continue;
					
					Long contactid = phoneCursor.getLong(PHONES_CONTACT_ID_INDEX);
					String contactName = phoneCursor.getString(PHONES_DISPLAY_NAME_INDEX);
					
					Long photoid = phoneCursor.getLong(PHONES_PHOTO_ID_INDEX);
					
					Bitmap contactPhoto = null;
					Uri uri = null;
					
					if(photoid > 0 ) {
						uri =ContentUris.withAppendedId(ContactsContract.Contacts.CONTENT_URI,contactid);
						InputStream input = ContactsContract.Contacts.openContactPhotoInputStream(resolver, uri);
						contactPhoto = BitmapFactory.decodeStream(input);
					}else {
						//如果没有头像，给一个默认图片
						contactPhoto = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
					}
					
					mContactsName.add(contactName);
					mContactsNumber.add(phoneNumber);
					mContactsPhonto.add(contactPhoto);
					mContactsPhontoUri.add(uri);
					
					//update UI every 10 contacts were read
					if (mContactsNumber.size() % 10 == 0) {
						
						//用publishProgress（）方法 可以调用 onProgressUpdate(Integer... values) 这个方法
						publishProgress(3);
					}
			    }
			}
			//update all contacts 
			publishProgress(3);
			return null;
		}
		
		protected void onPreExecute() {
		}

		protected void onProgressUpdate(Integer... values) {
			
			myAdapter.notifyDataSetChanged();
		
		}

	}
}