项目中需要使用ListView的下拉刷新，于是在网上找了找，有很多类似的项目，但是最终选择了xListView。
xListView的使用非常简单，项目本来还有上拉加载，但是对我来说没用，所以就去掉了，下面是使用代码，非常简单。
private void initView(View view) {
online_tv_name = view.findViewById(R.id.online_tv_name);
two_listView = view.findViewById(R.id.two_listView);
mainAdapter = new MainAdapter(getContext(),list);
two_listView.setAdapter(mainAdapter);
two_listView.setXListViewListener(this);
}
@Override
public void onRefresh() {
handler.postDelayed(new Runnable() {
@Override
public void run() {
list.add(new Online(100,"下拉刷新","呵呵","呵呵"));
mainAdapter.notifyDataSetChanged();
onLoad();
}
},1000);
}
private void onLoad() {
two_listView.stopRefresh();//停止刷新
@SuppressLint("SimpleDateFormat") SimpleDateFormat formatter = new SimpleDateFormat("MM-ddHH:mm:ss");//设置日期显示格式
Date curDate = new Date(System.currentTimeMillis());//获取当前时间
String str = formatter.format(curDate);// 将时间装换为设置好的格式
two_listView.setRefreshTime(str);//设置时间
}
上面的代码很好理解，initview用来初始化数据，onRefresh用来刷新数据，onLoad用来停止刷新。
如果有上拉加载需要的直接拖到最下面，有我的免费Demo。
项目很简单，copy进去几个文件就OK了，一共两个java文件，一个xml布局文件，还有一张刷新时的图片。
首先是java文件。自定义一下ListView：
package zj.it.bhne.gridengineeringsurvey.myutils.view;
import android.annotation.SuppressLint;
import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.view.animation.DecelerateInterpolator;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.Scroller;
import android.widget.TextView;
import zj.it.bhne.gridengineeringsurvey.R;
public class XListView extends ListView implements OnScrollListener {
private float mLastY = -1; // save event y
private Scroller mScroller; // used for scroll back
private OnScrollListener mScrollListener; // user's scroll listener
// the interface to trigger refresh and load more.
private IXListViewListener mListViewListener;
// -- header view
private XListViewHeader mHeaderView;
// header view content, use it to calculate the Header's height. And hide it
// when disable pull refresh.
private RelativeLayout mHeaderViewContent;
private TextView mHeaderTimeView;
private int mHeaderViewHeight; // header view's height
private boolean mEnablePullRefresh = true;
private boolean mPullRefreshing = false; // is refreashing.
// total list items, used to detect is at the bottom of listview.
private int mTotalItemCount;
// for mScroller, scroll back from header or footer.
private int mScrollBack;
private final static int SCROLLBACK_HEADER = 0;
private final static int SCROLLBACK_FOOTER = 1;
private final static int SCROLL_DURATION = 400; // scroll back duration
private final static int PULL_LOAD_MORE_DELTA = 50; // when pull up >= 50px
// at bottom, trigger
// load more.
private final static float OFFSET_RADIO = 1.8f; // support iOS like pull
// feature.
/**
* @param context
*/
public XListView(Context context) {
super(context);
initWithContext(context);
}
public XListView(Context context, AttributeSet attrs) {
super(context, attrs);
initWithContext(context);
}
public XListView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
initWithContext(context);
}
private void initWithContext(Context context) {
mScroller = new Scroller(context, new DecelerateInterpolator());
// XListView need the scroll event, and it will dispatch the event to
// user's listener (as a proxy).
super.setOnScrollListener(this);
// init header view
mHeaderView = new XListViewHeader(context);
mHeaderViewContent = mHeaderView
.findViewById(R.id.xlistview_header_content);
mHeaderTimeView = mHeaderView
.findViewById(R.id.xlistview_header_time);
addHeaderView(mHeaderView);
// init header height
mHeaderView.getViewTreeObserver().addOnGlobalLayoutListener(
new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
mHeaderViewHeight = mHeaderViewContent.getHeight();
getViewTreeObserver()
.removeGlobalOnLayoutListener(this);
}
});
}
/**
* enable or disable pull down refresh feature.
*
* @param enable
*/
public void setPullRefreshEnable(boolean enable) {
mEnablePullRefresh = enable;
if (!mEnablePullRefresh) { // disable, hide the content
mHeaderViewContent.setVisibility(View.INVISIBLE);
} else {
mHeaderViewContent.setVisibility(View.VISIBLE);
}
}
/**
* stop refresh, reset header view.
*/
public void stopRefresh() {
if (mPullRefreshing) {
mPullRefreshing = false;
resetHeaderHeight();
}
}
/**
* set last refresh time
*
* @param time
*/
public void setRefreshTime(String time) {
mHeaderTimeView.setText(time);
}
private void invokeOnScrolling() {
if (mScrollListener instanceof OnXScrollListener) {
OnXScrollListener l = (OnXScrollListener) mScrollListener;
l.onXScrolling(this);
}
}
private void updateHeaderHeight(float delta) {
mHeaderView.setVisiableHeight((int) delta
+ mHeaderView.getVisiableHeight());
if (mEnablePullRefresh && !mPullRefreshing) { // 未处于刷新状态，更新箭头
if (mHeaderView.getVisiableHeight() > mHeaderViewHeight) {
mHeaderView.setState(XListViewHeader.STATE_READY);
} else {
mHeaderView.setState(XListViewHeader.STATE_NORMAL);
}
}
setSelection(0); // scroll to top each time
}
/**
* reset header view's height.
*/
private void resetHeaderHeight() {
int height = mHeaderView.getVisiableHeight();
if (height == 0) // not visible.
return;
// refreshing and header isn't shown fully. do nothing.
if (mPullRefreshing && height <= mHeaderViewHeight) {
return;
}
int finalHeight = 0; // default: scroll back to dismiss header.
// is refreshing, just scroll back to show all the header.
if (mPullRefreshing && height > mHeaderViewHeight) {
finalHeight = mHeaderViewHeight;
}
mScrollBack = SCROLLBACK_HEADER;
mScroller.startScroll(0, height, 0, finalHeight - height,
SCROLL_DURATION);
// trigger computeScroll
invalidate();
}
@SuppressLint("ClickableViewAccessibility")
@Override
public boolean onTouchEvent(MotionEvent ev) {
if (mLastY == -1) {
mLastY = ev.getRawY();
}
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
mLastY = ev.getRawY();
break;
case MotionEvent.ACTION_MOVE:
final float deltaY = ev.getRawY() - mLastY;
mLastY = ev.getRawY();
if (getFirstVisiblePosition() == 0
&& (mHeaderView.getVisiableHeight() > 0 || deltaY > 0)) {
// the first item is showing, header has shown or pull down.
updateHeaderHeight(deltaY / OFFSET_RADIO);
invokeOnScrolling();
}
break;
default:
mLastY = -1; // reset
if (getFirstVisiblePosition() == 0) {
// invoke refresh
if (mEnablePullRefresh
&& mHeaderView.getVisiableHeight() > mHeaderViewHeight) {
mPullRefreshing = true;
mHeaderView.setState(XListViewHeader.STATE_REFRESHING);
if (mListViewListener != null) {
mListViewListener.onRefresh();
}
}
resetHeaderHeight();
}
break;
}
return super.onTouchEvent(ev);
}
@Override
public void computeScroll() {
if (mScroller.computeScrollOffset()) {
if (mScrollBack == SCROLLBACK_HEADER) {
mHeaderView.setVisiableHeight(mScroller.getCurrY());
}
postInvalidate();
invokeOnScrolling();
}
super.computeScroll();
}
@Override
public void setOnScrollListener(OnScrollListener l) {
mScrollListener = l;
}
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
if (mScrollListener != null) {
mScrollListener.onScrollStateChanged(view, scrollState);
}
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
// send to user's listener
mTotalItemCount = totalItemCount;
if (mScrollListener != null) {
mScrollListener.onScroll(view, firstVisibleItem, visibleItemCount,
totalItemCount);
}
}
public void setXListViewListener(IXListViewListener l) {
mListViewListener = l;
}
/**
* you can listen ListView.OnScrollListener or this one. it will invoke
* onXScrolling when header/footer scroll back.
*/
public interface OnXScrollListener extends OnScrollListener {
void onXScrolling(View view);
}
/**
* implements this interface to get refresh/load more event.
*/
public interface IXListViewListener {
void onRefresh();
}
}
另一个java文件是listview刷新时头部需要进行的操作以及计算：
public class XListViewHeader extends LinearLayout {
private static final String HINT_NORMAL = "下拉刷新";
private static final String HINT_READY = "松开刷新数据";
private static final String HINT_LOADING = "正在加载...";
// 正常状态
public final static int STATE_NORMAL = 0;
// 准备刷新状态，也就是箭头方向发生改变之后的状态
public final static int STATE_READY = 1;
// 刷新状态，箭头变成了progressBar
public final static int STATE_REFRESHING = 2;
// 布局容器，也就是根布局
private LinearLayout container;
// 箭头图片
private ImageView mArrowImageView;
// 刷新状态显示
private ProgressBar mProgressBar;
// 说明文本
private TextView mHintTextView;
// 记录当前的状态
private int mState;
// 用于改变箭头的方向的动画
private Animation mRotateUpAnim;
private Animation mRotateDownAnim;
public XListViewHeader(Context context) {
super(context);
initView(context);
}
public XListViewHeader(Context context, AttributeSet attrs) {
super(context, attrs);
initView(context);
}
@SuppressLint("InflateParams")
private void initView(Context context) {
mState = STATE_NORMAL;
// 初始情况下，设置下拉刷新view高度为0
LayoutParams lp = new LayoutParams(
LayoutParams.MATCH_PARENT, 0);
container = (LinearLayout) LayoutInflater.from(context).inflate(
R.layout.xlistview_header, null);
addView(container, lp);
// 初始化控件
mArrowImageView = findViewById(R.id.xlistview_header_arrow);
mHintTextView = findViewById(R.id.xlistview_header_hint_textview);
mProgressBar = findViewById(R.id.xlistview_header_progressbar);
// 初始化动画
mRotateUpAnim = new RotateAnimation(0.0f, -180.0f,
Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,
0.5f);
int ROTATE_ANIM_DURATION = 180;
mRotateUpAnim.setDuration(ROTATE_ANIM_DURATION);
mRotateUpAnim.setFillAfter(true);
mRotateDownAnim = new RotateAnimation(-180.0f, 0.0f,
Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,
0.5f);
mRotateDownAnim.setDuration(ROTATE_ANIM_DURATION);
mRotateDownAnim.setFillAfter(true);
}
// 设置header的状态
public void setState(int state) {
if (state == mState)
return;
// 显示进度
if (state == STATE_REFRESHING) {
mArrowImageView.clearAnimation();
mArrowImageView.setVisibility(View.INVISIBLE);
mProgressBar.setVisibility(View.VISIBLE);
} else {
// 显示箭头
mArrowImageView.setVisibility(View.VISIBLE);
mProgressBar.setVisibility(View.INVISIBLE);
}
switch (state) {
case STATE_NORMAL:
if (mState == STATE_READY) {
mArrowImageView.startAnimation(mRotateDownAnim);
}
if (mState == STATE_REFRESHING) {
mArrowImageView.clearAnimation();
}
mHintTextView.setText(HINT_NORMAL);
break;
case STATE_READY:
if (mState != STATE_READY) {
mArrowImageView.clearAnimation();
mArrowImageView.startAnimation(mRotateUpAnim);
mHintTextView.setText(HINT_READY);
}
break;
case STATE_REFRESHING:
mHintTextView.setText(HINT_LOADING);
break;
}
mState = state;
}
public void setVisiableHeight(int height) {
if (height < 0)
height = 0;
LayoutParams lp = (LayoutParams) container
.getLayoutParams();
lp.height = height;
container.setLayoutParams(lp);
}
public int getVisiableHeight() {
return container.getHeight();
}
public void show() {
container.setVisibility(View.VISIBLE);
}
public void hide() {
container.setVisibility(View.INVISIBLE);
}
下面是头文件的布局文件：
<?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="fill_parent"
android:layout_height="wrap_content"
android:gravity="bottom" >
<RelativeLayout
android:id="@+id/xlistview_header_content"
android:layout_width="fill_parent"
android:layout_height="60dp"
tools:ignore="UselessParent">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:gravity="center"
android:orientation="vertical" android:id="@+id/xlistview_header_text">
<TextView
android:id="@+id/xlistview_header_hint_textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/xlistview_header_hint_normal" />
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="3dp" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/xlistview_header_last_time"
android:textSize="12sp" />
<TextView
android:id="@+id/xlistview_header_time"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="12sp" />
</LinearLayout>
</LinearLayout>
<ImageView
android:id="@+id/xlistview_header_arrow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignStart="@id/xlistview_header_text"
android:layout_centerVertical="true"
android:layout_marginStart="-35dp"
android:src="@drawable/xlistview_arrow"
tools:ignore="ContentDescription" />
<ProgressBar
android:id="@+id/xlistview_header_progressbar"
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_alignStart="@id/xlistview_header_text"
android:layout_centerVertical="true"
android:layout_marginStart="-40dp"
android:visibility="invisible" />
</RelativeLayout>
</LinearLayout>下面这张图就是用来下拉刷新时显示的图片:
免费Demo在此
OK，就这样。