AsyncQueryHandler 异步查询数据

ListView主界面

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <ListView
        android:id="@+id/list_view"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:cacheColorHint="#00000000"
        android:scrollbars="none" />

</RelativeLayout>

ListView条目

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent">

		
	<ImageView
		android:id="@+id/image_view"
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:layout_alignParentLeft="true"
		android:layout_marginRight="5.0dip"
		android:src="@drawable/contact_list_icon" />
		
    <TextView
    	android:id="@+id/name"
    	android:textAppearance="?android:textAppearanceMedium"
    	android:layout_width="wrap_content"
    	android:layout_height="wrap_content"
    	android:layout_marginLeft="2.0dip"
    	android:layout_marginTop="6.0dip"
    	android:layout_marginRight="5.0dip"
    	android:singleLine="true"
    	android:layout_toRightOf="@id/image_view"
    	android:layout_alignTop="@id/image_view" />
    	
    <TextView
    	android:id="@+id/number"
    	android:textAppearance="?android:textAppearanceSmall"
    	android:ellipsize="marquee"
    	android:layout_width="wrap_content"
    	android:layout_height="wrap_content"
    	android:singleLine="true"
    	android:textColor="#AAAAAA"
    	android:layout_below="@id/name"
    	android:layout_alignLeft="@id/name"
    	android:layout_alignWithParentIfMissing="true" />
    	
</RelativeLayout>

主界面代码

package com.droid;

import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.content.AsyncQueryHandler;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
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 TestAsyncQueryHandler extends Activity {
	private ListView personList;
	private List<ContentValues> listData;

	private static final String NAME = "name", NUMBER = "number",
			SORT_KEY = "sort_key";

	private AsyncQueryHandler asyncQuery;

	private BaseAdapter adapter;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);

		setContentView(R.layout.main);
		personList = (ListView) findViewById(R.id.list_view);

		asyncQuery = new MyAsyncQueryHandler(getContentResolver());
		asyncQueryContact();
	}

	/**
	 * 查询操作
	 */
	private void asyncQueryContact() {
		// TODO Auto-generated method stub
		Uri uri = Uri.parse("content://com.android.contacts/data/phones");
		String[] projection = { "_id", "display_name", "data1", "sort_key" };
		asyncQuery.startQuery(0, null, uri, projection, null, null,
				"sort_key COLLATE LOCALIZED asc");
	}

	/**
	 * handler
	 * 
	 * @author Administrator
	 * 
	 */

	private class MyAsyncQueryHandler extends AsyncQueryHandler {

		public MyAsyncQueryHandler(ContentResolver cr) {
			super(cr);

		}

		@Override
		protected void onQueryComplete(int token, Object cookie, Cursor cursor) {
			if (cursor != null && cursor.getCount() > 0) {
				listData = new ArrayList<ContentValues>();
				// cursor.moveToFirst();
				for (int i = 0; i < cursor.getCount(); i++) {
					ContentValues cv = new ContentValues();
					cursor.moveToPosition(i);
					String name = cursor.getString(1);
					String number = cursor.getString(2);
					String sortKey = cursor.getString(3);
					if (number.startsWith("+86")) {
						cv.put(NAME, name);
						// process (+86)
						cv.put(NUMBER, number.substring(3));
						cv.put(SORT_KEY, sortKey);
					} else {
						cv.put(NAME, name);
						cv.put(NUMBER, number);
						cv.put(SORT_KEY, sortKey);
					}
					listData.add(cv);
				}
				if (listData.size() > 0) {
					setAdapter(listData);
				}
				cursor.close();
			}
		}

	}

	private void setAdapter(List<ContentValues> listData) {
		adapter = new ListAdapter(this, listData);
		personList.setAdapter(adapter);

	}

	private class ListAdapter extends BaseAdapter {

		private LayoutInflater inflater;
		private List<ContentValues> list;

		public ListAdapter(Context context, List<ContentValues> list) {
			this.inflater = LayoutInflater.from(context);
			this.list = list;
		}

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

		@Override
		public Object getItem(int position) {
			return list.get(position);
		}

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

		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			ViewHolder holder;
			if (convertView == null) {
				convertView = inflater.inflate(R.layout.list_item, null);
				holder = new ViewHolder();
				holder.name = (TextView) convertView.findViewById(R.id.name);
				holder.number = (TextView) convertView
						.findViewById(R.id.number);
				convertView.setTag(holder);
			} else {
				holder = (ViewHolder) convertView.getTag();
			}

			ContentValues cv = list.get(position);
			holder.name.setText(cv.getAsString(NAME));
			holder.number.setText(cv.getAsString(NUMBER));

			return convertView;
		}

		private class ViewHolder {
			TextView name;
			TextView number;
		}

	}

}