android 监听联系人数据库

package com.test.contentobserver;

import android.app.Activity;
import android.database.ContentObserver;
import android.os.Bundle;
import android.provider.Contacts.People;

public class TestContentObserver extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        this.getApplicationContext().getContentResolver().registerContentObserver (People.CONTENT_URI, true, contentObserver);
    }

    private class MyContentObserver extends ContentObserver {

        public MyContentObserver() {
            super(null);
        }

        @Override
        public void onChange(boolean selfChange) {
            super.onChange(selfChange);
        }

    }

    MyContentObserver contentObserver = new MyContentObserver();

}