Android SwipeRefreshLayout 官方下拉刷新控件

来源：互联网发布：淘宝售前客服用语编辑：程序博客网时间：2024/05/21 09:00

SwipeRefreshLayout在V4包下。

SwipeRefreshLayout只能有一个直接子View，可能是一个ListView或一个Layout或其他需要刷新的组件。

setOnRefreshListener 用于监听刷新的动作。SwipeRefreshLayout 下拉，就会有刷新的效果出来，触发该监听。

如果需要一个刷新的动画，setRefreshing(true)，停: setRefreshing(false)

如果要禁用刷新动画和手势响应，ssetEnable(false)，恢复setEnable(true)

下面是一个Demo：

import android.content.Context;
import android.support.v4.widget.SwipeRefreshLayout;
import android.util.AttributeSet;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewConfiguration;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ListView;

/**
* 继承自SwipeRefreshLayout,从而实现滑动到底部时上拉加载更多的功能.
*
* @author mrsimple
*/
public class RefershLayout extends SwipeRefreshLayout implements
       OnScrollListener {


   /**
   * 滑动到最下面时的上拉操作
   */

   private int mTouchSlop;
   /**
   * listview实例
   */
   private ListView mListView;

   /**
   * 上拉监听器, 到了最底部的上拉加载操作
   */
   private OnLoadListener mOnLoadListener;

   /**
   * ListView的加载中footer
   */
   private View mListViewFooter;

   /**
   * 按下时的y坐标
   */
   private int mYDown;
   /**
   * 抬起时的y坐标, 与mYDown一起用于滑动到底部时判断是上拉还是下拉
   */
   private int mLastY;
   /**
   * 是否在加载中 ( 上拉加载更多 )
   */
   private boolean isLoading = false;

   /**
   * @param context
   */
   public RefershLayout(Context context, AttributeSet attrs) {
       super(context, attrs);
       mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();

       mListViewFooter = LayoutInflater.from(context).inflate(
               R.layout.xlistview_footer, null, false);
   }

   public RefershLayout(Context context) {
       super(context);
       // TODO Auto-generated constructor stub
   }
   @Override
   protected void onLayout(boolean changed, int left, int top, int right,
           int bottom) {
       super.onLayout(changed, left, top, right, bottom);

       // 初始化ListView对象
       if (mListView == null) {
           getListView();
       }
   }

   /**
   * 获取ListView对象
   */
   private void getListView() {
       int childs = getChildCount();
       if (childs > 0) {
           View childView = getChildAt(0);
           if (childView instanceof ListView) {
               mListView = (ListView) childView;
               // 设置滚动监听器给ListView, 使得滚动的情况下也可以自动加载
               mListView.setOnScrollListener(this);
               Log.d(VIEW_LOG_TAG, "### 找到listview");
           }
       }
   }


   /*
   * (non-Javadoc)
   *
   * @see android.view.ViewGroup#dispatchTouchEvent(android.view.MotionEvent)
   */
   @Override
   public boolean dispatchTouchEvent(MotionEvent event) {
       final int action = event.getAction();

       switch (action) {
       case MotionEvent.ACTION_DOWN:
           // 按下
           mYDown = (int) event.getRawY();
           break;

       case MotionEvent.ACTION_MOVE:
           // 移动
           mLastY = (int) event.getRawY();
           break;

       case MotionEvent.ACTION_UP:
           // 抬起
           if (canLoad()) {
               loadData();
           }
           break;
       default:
           break;
       }

       return super.dispatchTouchEvent(event);
   }

   /**
   * 是否可以加载更多, 条件是到了最底部, listview不在加载中, 且为上拉操作.
   *
   * @return
   */
   private boolean canLoad() {
       return isBottom() && !isLoading && isPullUp();
   }

   /**
   * 判断是否到了最底部
   */
   private boolean isBottom() {

       if (mListView != null && mListView.getAdapter() != null) {
           return mListView.getLastVisiblePosition() == (mListView
                   .getAdapter().getCount() - 1);
       }
       return false;
   }

   /**
   * 是否是上拉操作
   *
   * @return
   */
   private boolean isPullUp() {
       return (mYDown - mLastY) >= mTouchSlop;
   }

   /**
   * 如果到了最底部,而且是上拉操作.那么执行onLoad方法
   */
   private void loadData() {
       if (mOnLoadListener != null) {
           // 设置状态
           setLoading(true);
           //
           mOnLoadListener.onLoad();
       }
   }

   /**
   * @param loading
   */
   public void setLoading(boolean loading) {
       isLoading = loading;
       if (isLoading) {
           mListView.addFooterView(mListViewFooter);
       } else {
           mListView.removeFooterView(mListViewFooter);
           mYDown = 0;
           mLastY = 0;
       }
   }

   /**
   * @param loadListener
   */
   public void setOnLoadListener(OnLoadListener loadListener) {
       mOnLoadListener = loadListener;
   }

   @Override
   public void onScrollStateChanged(AbsListView view, int scrollState) {

   }

   @Override
   public void onScroll(AbsListView view, int firstVisibleItem,
           int visibleItemCount, int totalItemCount) {
       // 滚动时到了最底部也可以加载更多
       if (canLoad()) {
           loadData();
       }
   }

   /**
   * 加载更多的监听器
   *
   * @author mrsimple
   */
   public static interface OnLoadListener {
       public void onLoad();
   }
}

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

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">



     <RelativeLayout
        android:id="@+id/xlistview_footer_content"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:padding="10dp">

        <ProgressBar

            android:id="@+id/xlistview_footer_progressbar"
            android:layout_width="40dp"
            android:layout_height="40dp"
            android:layout_centerInParent="true"
            android:indeterminateDrawable="@drawable/frame_loading"
            android:visibility="visible" />

        <TextView
            android:id="@+id/xlistview_footer_hint_textview"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:text="加载更多..." />
    </RelativeLayout>

</LinearLayout>

<com.example.swiperefershlayoutdemo.RefershLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:id="@+id/swipe_layout"
    android:layout_height="match_parent" >

    <ListView
        android:id="@+id/mylistview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</com.example.swiperefershlayoutdemo.RefershLayout>

《mainActivity》

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import com.example.swiperefershlayoutdemo.RefershLayout.OnLoadListener;

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.widget.SwipeRefreshLayout.OnRefreshListener;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.Toast;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // 模拟一些数据
        final List<String> datas = new ArrayList<String>();
        for (int i = 0; i < 20; i++) {
            datas.add("item - " + i);
        }
        // 构造适配器
        final BaseAdapter adapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1,
                datas);
        ListView mylistview=(ListView)findViewById(R.id.mylistview);
        mylistview.setAdapter(adapter);
        // 获取RefreshLayout实例
        final RefershLayout myRefreshListView = (RefershLayout)
                findViewById(R.id.swipe_layout);

        // 设置下拉刷新时的颜色值,颜色值需要定义在xml中
        myRefreshListView
                .setColorScheme(R.color.umeng_comm_text_topic_light_color,
                        R.color.umeng_comm_yellow, R.color.umeng_comm_green,
                        R.color.umeng_comm_linked_text);






        // 设置下拉刷新监听器
        myRefreshListView.setOnRefreshListener(new OnRefreshListener() {

            @Override
            public void onRefresh() {

                Toast.makeText(MainActivity.this, "refresh", Toast.LENGTH_SHORT).show();

                myRefreshListView.postDelayed(new Runnable() {

                    @Override
                    public void run() {
                        // 更新数据
                        datas.add(new Date().toGMTString());
                        adapter.notifyDataSetChanged();
                        // 更新完后调用该方法结束刷新
                        myRefreshListView.setRefreshing(false);
                    }
                }, 1000);
            }
        });

        // 加载监听器
        myRefreshListView.setOnLoadListener(new OnLoadListener() {

            @Override
            public void onLoad() {

                Toast.makeText(MainActivity.this, "load", Toast.LENGTH_SHORT).show();

                myRefreshListView.postDelayed(new Runnable() {

                    @Override
                    public void run() {
                        datas.add(new Date().toGMTString());
                        adapter.notifyDataSetChanged();
                        // 加载完后调用该方法
                        myRefreshListView.setLoading(false);
                    }
                }, 1500);

            }
        });
    }


    }

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