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SwipeRefreshLayout的简要说明及使用demo

在最新的 Android Support Library, revision 19.1.0 (March 2014) 添加了SwipeRefreshLayout控件。

版本发布的说明信息如下：

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.

链接：http://developer.android.com/intl/zh-cn/tools/support-library/index.html

SwipeRefreshLayout 的官方说明地址如下：

http://developer.android.com/intl/zh-cn/reference/android/support/v4/widget/SwipeRefreshLayout.html

几点重要的说明如下：

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 。

使用的demo 如下：

效果图：

核心的代码：

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;
        }
    }

}

主布局文件 xml：

<?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>