android自定义刷新类控件

android虽然定义了种类非常丰富的控件，但是有的时候这些自定义的控件还是不能满足我的要求，为了能够适配更多的需求，我们需要在原有的基础上进行自定义控件。

今天我向大家介绍的就是android中最常见的刷新类控件。因为我们最近正在参加一个项目，在项目组长的带领下，我学到了很多的东西，这对我的android技术的提升非常大，定义一个自定义控件可能不是很难，但是如何让这个自定义控件更加有效、更加快速地运行。

首先我们需要建立一个自定义控件类：

package com.example.ui.widget;

import com.example.androidtest.R;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.LinearInterpolator;
import android.view.animation.RotateAnimation;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;

/**
 * 下拉刷新控件
 * 
 * @author JeffLee 
 * @version 1.0
 * @created 2014-10-21
 */
public class PullToRefreshListView extends ListView implements OnScrollListener {

	private final static String TAG = "PullToRefreshListView";

	private static final int MAX_Y_OVERSCROLL_DISTANCE = 100;
	private Context mContext;
	private int mMaxYOverscrollDistance;

	// 下拉刷新标志
	private final static int PULL_To_REFRESH = 0;
	// 松开刷新标志
	private final static int RELEASE_To_REFRESH = 1;
	// 正在刷新标志
	public final static int REFRESHING = 2;
	// 刷新完成标志
	private final static int DONE = 3;

	private LayoutInflater inflater;

	private LinearLayout headView;
	private TextView tipsTextview;
	private TextView lastUpdatedTextView;
	private ImageView arrowImageView;
	private ProgressBar progressBar;
	// 用来设置箭头图标动画效果
	private RotateAnimation animation;
	private RotateAnimation reverseAnimation;

	// 用于保证startY的值在一个完整的touch事件中只被记录一次
	private boolean isRecored;

	private int headContentWidth;
	private int headContentHeight;
	private int headContentOriginalTopPadding;

	private int startY;
	private int firstItemIndex;
	private int currentScrollState;

	private int state;

	private boolean isBack;

	public OnRefreshListener refreshListener;
	public OnLoadMoreListener loadMoreListener;

	// -- footer view
	private PullToRefreshFooter mFooterView;
	private boolean mEnablePullLoad;
	private boolean mPullLoading = false;
	private boolean mIsFooterReady = false;

	private float mFirstY = -1; // save event y

	private boolean bloading = false;

	public PullToRefreshListView(Context context, AttributeSet attrs) {
		super(context, attrs);
		init(context);
	}

	public PullToRefreshListView(Context context, AttributeSet attrs,
			int defStyle) {
		super(context, attrs, defStyle);
		init(context);
	}

	public int getState() {
		return state;
	}

	private void init(Context context) {
		mContext = context;
		final DisplayMetrics metrics = mContext.getResources()
				.getDisplayMetrics();
		final float density = metrics.density;

		mMaxYOverscrollDistance = (int) (density * MAX_Y_OVERSCROLL_DISTANCE);
		// 设置滑动效果
		animation = new RotateAnimation(0, -180, Animation.RELATIVE_TO_SELF,
				0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
		animation.setInterpolator(new LinearInterpolator());
		animation.setDuration(200);
		animation.setFillAfter(true);

		reverseAnimation = new RotateAnimation(-180, 0,
				Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,
				0.5f);
		reverseAnimation.setInterpolator(new LinearInterpolator());
		reverseAnimation.setDuration(200);
		reverseAnimation.setFillAfter(true);

		inflater = LayoutInflater.from(context);
		headView = (LinearLayout) inflater.inflate(
				R.layout.pull_to_refresh_head, null);

		arrowImageView = (ImageView) headView
				.findViewById(R.id.head_arrowImageView);
		// arrowImageView.setMinimumWidth(50);
		// arrowImageView.setMinimumHeight(50);
		progressBar = (ProgressBar) headView
				.findViewById(R.id.head_progressBar);
		tipsTextview = (TextView) headView.findViewById(R.id.head_tipsTextView);
		lastUpdatedTextView = (TextView) headView
				.findViewById(R.id.head_lastUpdatedTextView);

		headContentOriginalTopPadding = headView.getPaddingTop();

		measureView(headView);
		headContentHeight = headView.getMeasuredHeight();
		headContentWidth = headView.getMeasuredWidth();

		headView.setPadding(headView.getPaddingLeft(), -1 * headContentHeight,
				headView.getPaddingRight(), headView.getPaddingBottom());
		headView.invalidate();

		addHeaderView(headView);

		// init footer view
		mFooterView = new PullToRefreshFooter(context);

		setOnScrollListener(this);
	}

	@Override
	public void setAdapter(ListAdapter adapter) {
		super.setAdapter(adapter);
	}

	// 需要有加载更多功能时候的设置adapter的方式
	public void setLoadMoreAdapter(ListAdapter adapter) {
		setAdapter(adapter);
		addFooterView();
	}

	public void addFooterView() {
		if (mIsFooterReady == false) {
			mIsFooterReady = true;
			mFooterView.setOnClickListener(new View.OnClickListener() {

				@Override
				public void onClick(View v) {
					// 不在下拉刷新状态，以及没有全部加载,且不在加载更多的状态下进行点击刷新
					if (state != REFRESHING && !mPullLoading) { //
						startLoadMore();
					}
				}
			});
			addFooterView(mFooterView);
		}
	}

	/**
	 * stop load more, reset footer view.
	 */
	// public void stopLoadMore() {
	// if (mPullLoading == true) {
	// mPullLoading = false;
	// mFooterView.setState(XListViewFooter.STATE_NORMAL);
	// }
	// }
	public void completeLoadMore(int status) {
		if (mPullLoading == true) {
			state = PULL_To_REFRESH;
			mPullLoading = false;
			// mFooterView.setState(status);
		}
		mFooterView.setState(status);
	}

	public void setFooterState(int status) {
		mFooterView.setState(status);
	}

	public int getFooterState() {
		return mFooterView.getState();
	}

	private void startLoadMore() {
		// 设置了加载更多的监听器，以及加载更多状态不是数据加载完毕，和为空数据的时候，都可以进行上滑刷新
		if (loadMoreListener != null
				&& mFooterView.getState() != PullToRefreshFooter.STATE_LOADFULL
				&& mFooterView.getState() != PullToRefreshFooter.STATE_NULL) {
			mPullLoading = true;
			state = REFRESHING;
			mFooterView.setState(PullToRefreshFooter.STATE_LOADING);
			loadMoreListener.onLoadMore();
		}

	}

	public void settingOnScroll(AbsListView view, int firstVisiableItem,
			int visibleItemCount, int totalItemCount) {
		firstItemIndex = firstVisiableItem;
		// if (firstVisiableItem + visibleItemCount >=
		// totalItemCount){//currentScrollState == SCROLL_STATE_TOUCH_SCROLL
		// if (state != REFRESHING
		// && ! mPullLoading) {
		// startLoadMore();
		// }
		// }
	}

	public void settingOnScrollStateChanged(AbsListView view, int scrollState) {
		currentScrollState = scrollState;
		if (scrollState == SCROLL_STATE_IDLE && getCount() > 0) {
			// 判断滚动到底部
			if (view.getLastVisiblePosition() == (view.getCount() - 1)) {
				if (state != REFRESHING && !mPullLoading) {
					startLoadMore();
				}
			}
		}
	}

	@Override
	public void onScroll(AbsListView view, int firstVisiableItem,
			int visibleItemCount, int totalItemCount) {
		settingOnScroll(view, firstVisiableItem, visibleItemCount,
				totalItemCount);
	}

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

	public final boolean getLoadingState() {
		return bloading;
	}

	public final void setLoadingState(boolean bloading) {
		// Log.i(TAG, "setLoadingState bloading =" + bloading);
		this.bloading = bloading;
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {
		if (mFirstY == -1) {
			mFirstY = event.getRawY();
		}
		switch (event.getAction()) {
		case MotionEvent.ACTION_DOWN:
			if (firstItemIndex == 0 && !isRecored) {
				startY = (int) event.getY();
				isRecored = true;
			}
			break;

		case MotionEvent.ACTION_CANCEL:// 失去焦点&取消动作
		case MotionEvent.ACTION_UP:

			if (state != REFRESHING) {
				if (state == DONE) { // 当前-抬起-ACTION_UP：DONE什么都不做
				} else if (state == PULL_To_REFRESH) { // 当前-抬起-ACTION_UP：PULL_To_REFRESH-->DONE-由下拉刷新状态到刷新完成状态
					state = DONE;
					changeHeaderViewByState();
				} else if (state == RELEASE_To_REFRESH) { // 当前-抬起-ACTION_UP：RELEASE_To_REFRESH-->REFRESHING-由松开刷新状态，到刷新完成状态
					state = REFRESHING;
					changeHeaderViewByState();
					onRefresh();
				}
				final float deltaY = event.getRawY() - mFirstY;
				if ((deltaY < 0) && !mPullLoading
						&& getLastVisiblePosition() == getCount() - 1) {
					startLoadMore();
				}
				mFirstY = -1; // reset
			}

			isRecored = false;
			isBack = false;

			break;

		case MotionEvent.ACTION_MOVE:
			int tempY = (int) event.getY();
			if (!isRecored && firstItemIndex == 0) {
				isRecored = true;
				startY = tempY;
			}
			// 如果正在加载，则不能进行刷新操作
			if (bloading) {
				break;
			}
			// Log.i(TAG,"tempY =" + tempY +";startY = "+startY);
			if (state != REFRESHING && isRecored) {
				// 可以松开刷新了
				if (state == RELEASE_To_REFRESH) {
					// 往上推，推到屏幕足够掩盖head的程度，但还没有全部掩盖
					if ((tempY - startY < headContentHeight + 20)
							&& (tempY - startY) > 0) {
						state = PULL_To_REFRESH;
						changeHeaderViewByState();
					} else if (tempY - startY <= 0) { // 一下子推到顶
						state = DONE;
						changeHeaderViewByState();
					} else { // 往下拉，或者还没有上推到屏幕顶部掩盖head
						// 不用进行特别的操作，只用更新paddingTop的值就行了
					}
				} else if (state == PULL_To_REFRESH) { // 还没有到达显示松开刷新的时候,DONE或者是PULL_To_REFRESH状态
					// 下拉到可以进入RELEASE_TO_REFRESH的状态
					if (tempY - startY >= headContentHeight + 20) {
						state = RELEASE_To_REFRESH;
						isBack = true;
						changeHeaderViewByState();
					}
					// 上推到顶了
					else if (tempY - startY <= 0) {
						state = DONE;
						changeHeaderViewByState();
					}
				} else if (state == DONE) { // done状态下
					if (tempY - startY > 0) {
						state = PULL_To_REFRESH;
						changeHeaderViewByState();
					}
				}

				// 更新headView的size
				if (state == PULL_To_REFRESH) {
					int topPadding = ((-1 * headContentHeight + (tempY - startY)));

					headView.setPadding(headView.getPaddingLeft(), topPadding,
							headView.getPaddingRight(),
							headView.getPaddingBottom());
					headView.invalidate();
				}

				// 更新headView的paddingTop
				if (state == RELEASE_To_REFRESH) {
					int topPadding = ((tempY - startY - headContentHeight));
					if (topPadding > mMaxYOverscrollDistance)
						topPadding = mMaxYOverscrollDistance;

					headView.setPadding(headView.getPaddingLeft(), topPadding,
							headView.getPaddingRight(),
							headView.getPaddingBottom());
					headView.invalidate();
				}
			}
			break;
		default:
			break;
		}

		if (state == RELEASE_To_REFRESH) {
			return true;
		}
		return super.onTouchEvent(event);
	}

	// 当状态改变时候，调用该方法，以更新界面
	private void changeHeaderViewByState() {
		switch (state) {
		case RELEASE_To_REFRESH:

			arrowImageView.setVisibility(View.VISIBLE);
			progressBar.setVisibility(View.GONE);
			tipsTextview.setVisibility(View.VISIBLE);
			lastUpdatedTextView.setVisibility(View.VISIBLE);

			arrowImageView.clearAnimation();
			arrowImageView.startAnimation(animation);

			tipsTextview.setText(R.string.pull_to_refresh_release_label);
			break;
		case PULL_To_REFRESH:

			progressBar.setVisibility(View.GONE);
			tipsTextview.setVisibility(View.VISIBLE);
			lastUpdatedTextView.setVisibility(View.VISIBLE);
			arrowImageView.clearAnimation();
			arrowImageView.setVisibility(View.VISIBLE);
			if (isBack) {
				isBack = false;
				arrowImageView.clearAnimation();
				arrowImageView.startAnimation(reverseAnimation);
			}
			tipsTextview.setText(R.string.pull_to_refresh_pull_label);
			break;

		case REFRESHING:
			headView.setPadding(headView.getPaddingLeft(),
					headContentOriginalTopPadding, headView.getPaddingRight(),
					headView.getPaddingBottom());
			headView.invalidate();

			progressBar.setVisibility(View.VISIBLE);
			arrowImageView.clearAnimation();
			arrowImageView.setVisibility(View.GONE);
			tipsTextview.setText(R.string.pull_to_refresh_refreshing_label);
			lastUpdatedTextView.setVisibility(View.GONE);
			break;
		case DONE: {
			headView.setPadding(headView.getPaddingLeft(), -1
					* headContentHeight, headView.getPaddingRight(),
					headView.getPaddingBottom());

			progressBar.setVisibility(View.GONE);
			arrowImageView.clearAnimation();
			// 此处更换图标
			// arrowImageView.setImageResource(R.drawable.ic_pulltorefresh_arrow);
			Bitmap arrow = BitmapFactory.decodeResource(getResources(),
					R.drawable.ic_pulltorefresh_arrow);
			Drawable background = new BitmapDrawable(arrow);
			arrowImageView.setBackgroundDrawable(background);
			tipsTextview.setText(R.string.pull_to_refresh_pull_label);
			lastUpdatedTextView.setVisibility(View.VISIBLE);
			headView.invalidate();
		}
			break;
		}
	}

	// 点击刷新
	public void clickRefresh() {
		setSelection(0);
		state = REFRESHING;
		changeHeaderViewByState();
		onRefresh();
	}

	public void setOnRefreshListener(OnRefreshListener refreshListener) {
		this.refreshListener = refreshListener;
	}

	public void setOnLoadMoreListener(OnLoadMoreListener loadMoreListener) {
		this.loadMoreListener = loadMoreListener;
	}

	public interface OnRefreshListener {
		public void onRefresh();

	}

	public interface OnLoadMoreListener {
		public void onLoadMore();
	}

	public void onRefreshComplete(String update) {
		lastUpdatedTextView.setText(update);
		onRefreshComplete();
	}

	public void firstRefreshing() {
		state = REFRESHING;
		headView.setPadding(0, 10, 0, 0);
		progressBar.setVisibility(View.VISIBLE);
		arrowImageView.clearAnimation();
		arrowImageView.setVisibility(View.GONE);
		tipsTextview.setText(R.string.pull_to_refresh_refreshing_label);
		lastUpdatedTextView.setVisibility(View.GONE);
	}

	/**
	 * stop refresh, reset header view.
	 */
	public void stopRefresh() {
		state = PULL_To_REFRESH;
		changeHeaderViewByState();
	}

	public void onRefreshComplete() {
		state = DONE;
		changeHeaderViewByState();
		setSelection(0);
	}

	public void onRefreshComplete(int loadMoreStatus) {
		onRefreshComplete();
		mFooterView.setState(loadMoreStatus);
	}

	private void onRefresh() {
		if (refreshListener != null) {
			refreshListener.onRefresh();
		}
	}

	// 计算headView的width及height值
	private void measureView(View child) {
		ViewGroup.LayoutParams p = child.getLayoutParams();
		if (p == null) {
			p = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT,
					ViewGroup.LayoutParams.WRAP_CONTENT);
		}
		int childWidthSpec = ViewGroup.getChildMeasureSpec(0, 0 + 0, p.width);
		int lpHeight = p.height;
		int childHeightSpec;
		if (lpHeight > 0) {
			childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight,
					MeasureSpec.EXACTLY);
		} else {
			childHeightSpec = MeasureSpec.makeMeasureSpec(0,
					MeasureSpec.UNSPECIFIED);
		}
		child.measure(childWidthSpec, childHeightSpec);
	}
	/*
	 * @Override protected boolean overScrollBy(int deltaX, int deltaY, int
	 * scrollX, int scrollY, int scrollRangeX, int scrollRangeY, int
	 * maxOverScrollX, int maxOverScrollY, boolean isTouchEvent) { // This is
	 * where the magic happens, we have replaced the incoming // maxOverScrollY
	 * with our own custom variable mMaxYOverscrollDistance;
	 * 
	 * return super.overScrollBy(deltaX, deltaY, scrollX, scrollY, scrollRangeX,
	 * scrollRangeY, maxOverScrollX, mMaxYOverscrollDistance, isTouchEvent); }
	 */
}

下面是pull_to_refresh_head.xml文件：

<?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="fill_parent"
    android:clickable="true"
    android:focusable="false"
    android:orientation="vertical" >

    <RelativeLayout
        android:id="@+id/head_contentLayout"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:paddingBottom="10dip"
        android:paddingTop="10dip" >

        <ImageView
            android:id="@+id/head_arrowImageView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true"
            android:layout_centerVertical="true"
            android:layout_marginLeft="50dp"
            android:background="@drawable/ic_pulltorefresh_arrow" />

        <FrameLayout
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:layout_alignParentLeft="true"
            android:layout_centerVertical="true"
            android:layout_marginLeft="100dip"
            android:layout_marginRight="10dip"
            android:paddingBottom="10dip"
            android:paddingTop="10dip" >

            <ProgressBar
                android:id="@+id/head_progressBar"
                style="@style/loading_small"
                android:visibility="gone" />
        </FrameLayout>

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:gravity="center_horizontal"
            android:orientation="vertical" >

            <TextView
                android:id="@+id/head_tipsTextView"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/pull_to_refresh_pull_label"
                android:textColor="@color/list_title" />

            <TextView
                android:id="@+id/head_lastUpdatedTextView"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:textColor="@color/list_title"
                android:textSize="10sp"
                android:visibility="gone" />
        </LinearLayout>
    </RelativeLayout>

</LinearLayout>

package com.example.ui.widget;

import com.example.androidtest.R;

import android.content.Context;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.RelativeLayout;
import android.widget.TextView;

public class PullToRefreshFooter extends RelativeLayout {
	public final static int STATE_NORMAL = 0; //正常状态，还有更多需要加载
	public final static int STATE_READY = 1;
	public final static int STATE_LOADING = 2; //正在加载中
	public final static int STATE_LOADFULL = 3;//数据全部加载完
	public final static int STATE_NULL = 4;//没有数据，初始状态
	private Context mContext;

	private View mContentView;
	private View mProgressBar;
	private TextView mHintView;
	
	private int state;
	
	public PullToRefreshFooter(Context context) {
		super(context);
		initView(context);
		setVisibility(View.GONE);
	}
	
	public PullToRefreshFooter(Context context, AttributeSet attrs) {
		super(context, attrs);
		initView(context);
	}

	
	public void setState(int state) {
		this.state = state;
//		mHintView.setVisibility(View.INVISIBLE);
//		mProgressBar.setVisibility(View.INVISIBLE);
//		mHintView.setVisibility(View.INVISIBLE);
		mProgressBar.setVisibility(View.GONE);
		mHintView.setVisibility(View.VISIBLE);
		setVisibility(View.VISIBLE);
		if (state == STATE_READY) {
			mHintView.setText(R.string.load_ready);
		} else if (state == STATE_LOADING) {
			mProgressBar.setVisibility(View.VISIBLE);
			mHintView.setText(R.string.load_ing);
		} else if (state == STATE_LOADFULL){
			mHintView.setText(R.string.load_full);
		} else if (state == STATE_NULL) {
			mHintView.setText(R.string.load_empty);
			//setVisibility(View.GONE);
		} else {
			mHintView.setText(R.string.load_more);
		}
	}
	public int getState() {
		return state;
	}
	public void setBottomMargin(int height) {
		if (height < 0) return ;
		RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams)mContentView.getLayoutParams();
		lp.bottomMargin = height;
		mContentView.setLayoutParams(lp);
	}
	
	public int getBottomMargin() {
		RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams)mContentView.getLayoutParams();
		return lp.bottomMargin;
	}
	
	
	/**
	 * normal status
	 */
	public void normal() {
		mHintView.setVisibility(View.VISIBLE);
		mProgressBar.setVisibility(View.GONE);
	}
	
	
	/**
	 * loading status 
	 */
	public void loading() {
		mHintView.setVisibility(View.GONE);
		mProgressBar.setVisibility(View.VISIBLE);
	}
	
	/**
	 * hide footer when disable pull load more
	 */
	public void hide() {
		RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams)mContentView.getLayoutParams();
		lp.height = 0;
		mContentView.setLayoutParams(lp);
	}
	
	/**
	 * show footer
	 */
	public void show() {
		RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams)mContentView.getLayoutParams();
		lp.height = android.view.ViewGroup.LayoutParams.WRAP_CONTENT;
		mContentView.setLayoutParams(lp);
	}
	
	private void initView(Context context) {
		mContext = context;
		RelativeLayout moreView = (RelativeLayout)LayoutInflater.from(mContext).inflate(R.layout.listview_footer, null);
		addView(moreView);
		moreView.setLayoutParams(new RelativeLayout.LayoutParams(android.view.ViewGroup.LayoutParams.FILL_PARENT, android.view.ViewGroup.LayoutParams.WRAP_CONTENT));
		
		mContentView = moreView.findViewById(R.id.listview_foot_content);
		mProgressBar = moreView.findViewById(R.id.listview_foot_progress);
		mHintView = (TextView)moreView.findViewById(R.id.listview_foot_more);
	}
	
	
}

下面是listview_footer.xml文件：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/listview_foot_content"
    android:orientation="horizontal"
    android:layout_width="fill_parent"
	android:layout_height="wrap_content"
    android:gravity="center"
    android:padding="3dp"
    android:clickable="true"
    android:focusable="false">
	
    <TextView android:id="@+id/listview_foot_more"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:padding="5dp"
        android:textColor="@color/list_subTitle"
        android:text="@string/load_empty"/>
    
	<ProgressBar 
		android:id="@+id/listview_foot_progress"
		android:layout_toLeftOf="@id/listview_foot_more"
		android:layout_centerVertical="true"
		style="@style/loading_small"/>

</RelativeLayout>

然后我们就可以使用这个刷新类的自定义控件了，

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".PullRefreshActivity" >

    <com.example.ui.widget.PullToRefreshListView
        android:id="@+id/listview"
        style="@style/common_listview"
        android:layout_width="match_parent"
        android:divider="@drawable/divided_line"
        android:dividerHeight="1dp"
        android:listSelector="@drawable/listview_item_nocolor_selector"
        android:paddingLeft="8dp"
        android:paddingRight="8dp"
        android:scrollbars="none" >
    </com.example.ui.widget.PullToRefreshListView>

</LinearLayout>

然后再Activity中加载这个控件：

package com.example.androidtest;

import com.example.ui.adapter.PullRefreshAdapter;
import com.example.ui.widget.PullToRefreshListView;
import com.example.ui.widget.PullToRefreshListView.OnRefreshListener;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.widget.Toast;

public class PullRefreshActivity extends Activity {

	private Context mContext;
	private PullRefreshAdapter pullRefreshAdapter;

	private PullToRefreshListView listView;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_pulltorefresh);
		initView();
		initListView();
	}

	private void initView() {
		mContext = this;
		listView = (PullToRefreshListView) findViewById(R.id.listview);
	}

	private void initListView() {
		pullRefreshAdapter = new PullRefreshAdapter(mContext);
		listView.setLoadMoreAdapter(pullRefreshAdapter);

		listView.setOnRefreshListener(new OnRefreshListener() {

			@Override
			public void onRefresh() {
				// TODO Auto-generated method stub
				Toast.makeText(mContext, "哈哈", Toast.LENGTH_SHORT).show();
			}
		});
	}
}

package com.example.ui.adapter;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;

public class PullRefreshAdapter extends BaseAdapter {
	private Context mContext;

	public PullRefreshAdapter(Context context) {
		super();
		this.mContext = context;
	}

	@Override
	public int getCount() {
		// TODO Auto-generated method stub
		return 0;
	}

	@Override
	public Object getItem(int position) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public long getItemId(int position) {
		// TODO Auto-generated method stub
		return 0;
	}

	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		// TODO Auto-generated method stub
		return null;
	}

}

得到的效果如下：

上面显示出来了加载刷新的功能，可以在需要刷新的时候显示这个控件，这样对UI显示地比较方面。由于时间比较仓促，暂时先放上源码，以后再好好分析源码，请大家多多指教。