Changes for v4 support library:

         Added the SwipeRefreshLayout class, which enables users to refresh the contents of a view with a vertical swipe gesture.

        Fixed accessibility issues with navigation drawers.

Changes for v7 appcompat library:

        Fixed background issues with the action bar.

1.  SwipeRefreshLayout 是用来做下拉刷新的，可以实现Google Now上的下拉刷新效果

2.  SwipeRefreshLayout 只能有一个直接的子view，也就是说SwipeRefreshLayout 只能直接包裹一个子view（当然这个子view可以包含多个view）,

如果不满足这个条件，运行的时候会报如下的错误：

java.lang.IllegalStateException: SwipeRefreshLayout can host only one direct child

3. SwipeRefreshLayout 包裹的子view必须是可以支持下拉刷新手势的，例如ListView和ScrollView 。

package com.hsx.demo;

import java.util.ArrayList;

import java.util.List;

import java.util.Random;

import android.app.Activity;

import android.content.Context;

import android.os.Bundle;

import android.os.Handler;

import android.os.Message;

import android.support.v4.widget.SwipeRefreshLayout;

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 Activity implements SwipeRefreshLayout.OnRefreshListener {

    private SwipeRefreshLayout swipeLayout;

    List<String> data = new ArrayList<String>();

    MyAdapter adapter;

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        initData();

        swipeLayout = (SwipeRefreshLayout) findViewById(R.id.swipe_container);

        swipeLayout.setOnRefreshListener(this);

        swipeLayout.setColorScheme(android.R.color.holo_blue_bright, android.R.color.holo_green_light, android.R.color.holo_orange_light,

                android.R.color.holo_red_light);

        ListView listView = (ListView) findViewById(R.id.test_listview);

        adapter = new MyAdapter();

        listView.setAdapter(adapter);

    }

    private void initData() {

        data.add("苏州");

        data.add("北京");

        data.add("上海");

    }

    Handler handler = new Handler() {

        @Override

        public void handleMessage(Message msg) {

            super.handleMessage(msg);

            swipeLayout.setRefreshing(false);

            adapter.notifyDataSetChanged();

        }

    };

    public void onRefresh() {

        new Thread(new Runnable() {

            @Override

            public void run() {

                try {

                    Thread.sleep(5000);

                } catch (InterruptedException e) {

                    e.printStackTrace();

                }

                Random random = new Random();

                data.add("天津" + random.nextInt(100));

                handler.sendEmptyMessage(1000);

            }

        }).start();

    }

    private class MyAdapter extends BaseAdapter {

        @Override

        public int getCount() {

            return data.size();

        }

        @Override

        public Object getItem(int position) {

            return data.get(position);

        }

        @Override

        public long getItemId(int position) {

            return 0;

        }

        @Override

        public View getView(int position, View convertView, ViewGroup parent) {

            LayoutInflater inflater = (LayoutInflater) MainActivity.this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

            convertView = inflater.inflate(R.layout.item, null);

            TextView tvItem = (TextView) convertView.findViewById(R.id.item_tv);

            tvItem.setText(data.get(position));

            return convertView;

        }

    }

}

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical" >

    <android.support.v4.widget.SwipeRefreshLayout

        android:id="@+id/swipe_container"

        android:layout_width="match_parent"

        android:layout_height="match_parent" >

        <ListView

            android:id="@+id/test_listview"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:background="@android:color/white" >

        </ListView>

    </android.support.v4.widget.SwipeRefreshLayout>

</LinearLayout>