在android中最重要的常用组件之一ListView,几乎任何应用都有他们的影子。但我们每次在使用的时候总是忙于配置各种事件监听,特别是他的下拉刷新和加载更多。
下面的是框架中的源代码,一般不需要修改,直接导入就行了
前几天在github网站上看到一个比较好的开源框架。使用也是非常简单,我们只需要在onRefresh()和onLoadMore() 去加载我们的数据,他就会自动加到ListView中,
package me.maxwin; import java.util.ArrayList; import java.util.Random; import me.maxwin.view.XListView; import me.maxwin.view.XListView.IXListViewListener; import android.app.Activity; import android.os.Bundle; import android.os.Handler; import android.widget.ArrayAdapter; public class XListViewActivity extends Activity implements IXListViewListener { private XListView mListView; private MyAdapter mAdapter; private ArrayList<Person> items = new ArrayList<Person>(); private Handler mHandler; private int start = 0; private static int refreshCnt = 0; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); geneItems(); mListView = (XListView) findViewById(R.id.xListView); mListView.setPullLoadEnable(true); mAdapter = new MyAdapter(this, items); mListView.setAdapter(mAdapter); // mListView.setPullLoadEnable(false); // mListView.setPullRefreshEnable(false); mListView.setXListViewListener(this); mHandler = new Handler(); } private void geneItems() { Random r = new Random(); for (int i = 0; i != 20; ++i) { items.add(new Person("qingxue " + (++start),"1358888"+r.nextInt(10)+r.nextInt(10)+r.nextInt(10)+r.nextInt(10))); } } private void onLoad() { mListView.stopRefresh(); mListView.stopLoadMore(); mListView.setRefreshTime("刚刚"); } //下拉刷新 @Override public void onRefresh() { mHandler.postDelayed(new Runnable() { @Override public void run() { start = ++refreshCnt; items.clear(); geneItems(); // mAdapter.notifyDataSetChanged(); //mAdapter = new ArrayAdapter<String>(XListViewActivity.this, R.layout.list_item, items); //mListView.setAdapter(mAdapter); mAdapter.notifyDataSetChanged(); onLoad(); } }, 2000); } //加载更多 @Override public void onLoadMore() { mHandler.postDelayed(new Runnable() { @Override public void run() { geneItems(); mAdapter.notifyDataSetChanged(); onLoad(); } }, 2000); } }
另外还有适配器,这个必须自己写的,要看你生成什么样的条目了,我只是为了演示一个简单的实现
package me.maxwin; import java.util.ArrayList; import java.util.List; import android.content.Context; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.TextView; public class MyAdapter extends BaseAdapter { private LayoutInflater inflater; private List<Person> list; public MyAdapter(Context context){ this.inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); this.list = new ArrayList<Person>(); } public MyAdapter(Context context,List<Person> list){ this.inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); this.list = list; } @Override public int getCount() { return list.size(); } @Override public Object getItem(int position) { return list.get(position); } @Override public long getItemId(int position) { return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { TextView nameView = null; TextView phoneView = null; if(convertView==null){ convertView = inflater.inflate(R.layout.list_item, null);//生成条目界面对象 nameView = (TextView) convertView.findViewById(R.id.list_item_username); phoneView = (TextView) convertView.findViewById(R.id.list_item_phone); ViewCache cache = new ViewCache(); cache.nameView = nameView; cache.phoneView = phoneView; convertView.setTag(cache); }else{ ViewCache cache = (ViewCache) convertView.getTag(); nameView = cache.nameView; phoneView = cache.phoneView; } Person person = list.get(position); //下面代码实现数据绑定 nameView.setText(person.getUsername()); phoneView.setText(person.getNumber()); return convertView; } private final class ViewCache{ public TextView nameView; public TextView phoneView; } }
下面的是框架中的源代码,一般不需要修改,直接导入就行了
/** * @file XListView.java * @package me.maxwin.view * @create Mar 18, 2012 6:28:41 PM * @author Maxwin * @description An ListView support (a) Pull down to refresh, (b) Pull up to load more. * Implement IXListViewListener, and see stopRefresh() / stopLoadMore(). */ package me.maxwin.view; import me.maxwin.R; 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.ListAdapter; import android.widget.ListView; import android.widget.RelativeLayout; import android.widget.Scroller; import android.widget.TextView; 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. // -- footer view private XListViewFooter mFooterView; private boolean mEnablePullLoad; private boolean mPullLoading; private boolean mIsFooterReady = false; // 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 = (RelativeLayout) mHeaderView .findViewById(R.id.xlistview_header_content); mHeaderTimeView = (TextView) mHeaderView .findViewById(R.id.xlistview_header_time); addHeaderView(mHeaderView); // init footer view mFooterView = new XListViewFooter(context); // init header height mHeaderView.getViewTreeObserver().addOnGlobalLayoutListener( new OnGlobalLayoutListener() { @Override public void onGlobalLayout() { mHeaderViewHeight = mHeaderViewContent.getHeight(); getViewTreeObserver() .removeGlobalOnLayoutListener(this); } }); } @Override public void setAdapter(ListAdapter adapter) { // make sure XListViewFooter is the last footer view, and only add once. if (mIsFooterReady == false) { mIsFooterReady = true; addFooterView(mFooterView); } super.setAdapter(adapter); } /** * 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); } } /** * enable or disable pull up load more feature. * * @param enable */ public void setPullLoadEnable(boolean enable) { mEnablePullLoad = enable; if (!mEnablePullLoad) { mFooterView.hide(); mFooterView.setOnClickListener(null); } else { mPullLoading = false; mFooterView.show(); mFooterView.setState(XListViewFooter.STATE_NORMAL); // both "pull up" and "click" will invoke load more. mFooterView.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { startLoadMore(); } }); } } /** * stop refresh, reset header view. */ public void stopRefresh() { if (mPullRefreshing == true) { mPullRefreshing = false; resetHeaderHeight(); } } /** * stop load more, reset footer view. */ public void stopLoadMore() { if (mPullLoading == true) { mPullLoading = false; mFooterView.setState(XListViewFooter.STATE_NORMAL); } } /** * 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(); } private void updateFooterHeight(float delta) { int height = mFooterView.getBottomMargin() + (int) delta; if (mEnablePullLoad && !mPullLoading) { if (height > PULL_LOAD_MORE_DELTA) { // height enough to invoke load // more. mFooterView.setState(XListViewFooter.STATE_READY); } else { mFooterView.setState(XListViewFooter.STATE_NORMAL); } } mFooterView.setBottomMargin(height); // setSelection(mTotalItemCount - 1); // scroll to bottom } private void resetFooterHeight() { int bottomMargin = mFooterView.getBottomMargin(); if (bottomMargin > 0) { mScrollBack = SCROLLBACK_FOOTER; mScroller.startScroll(0, bottomMargin, 0, -bottomMargin, SCROLL_DURATION); invalidate(); } } private void startLoadMore() { mPullLoading = true; mFooterView.setState(XListViewFooter.STATE_LOADING); if (mListViewListener != null) { mListViewListener.onLoadMore(); } } @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(); } else if (getLastVisiblePosition() == mTotalItemCount - 1 && (mFooterView.getBottomMargin() > 0 || deltaY < 0)) { // last item, already pulled up or want to pull up. updateFooterHeight(-deltaY / OFFSET_RADIO); } 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(); } else if (getLastVisiblePosition() == mTotalItemCount - 1) { // invoke load more. if (mEnablePullLoad && mFooterView.getBottomMargin() > PULL_LOAD_MORE_DELTA) { startLoadMore(); } resetFooterHeight(); } break; } return super.onTouchEvent(ev); } @Override public void computeScroll() { if (mScroller.computeScrollOffset()) { if (mScrollBack == SCROLLBACK_HEADER) { mHeaderView.setVisiableHeight(mScroller.getCurrY()); } else { mFooterView.setBottomMargin(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 { public void onXScrolling(View view); } /** * implements this interface to get refresh/load more event. */ public interface IXListViewListener { public void onRefresh(); public void onLoadMore(); } }
/** * @file XFooterView.java * @create Mar 31, 2012 9:33:43 PM * @author Maxwin * @description XListView's footer */ package me.maxwin.view; import me.maxwin.R; import android.content.Context; import android.util.AttributeSet; import android.view.LayoutInflater; import android.view.View; import android.widget.LinearLayout; import android.widget.TextView; public class XListViewFooter extends LinearLayout { public final static int STATE_NORMAL = 0; public final static int STATE_READY = 1; public final static int STATE_LOADING = 2; private Context mContext; private View mContentView; private View mProgressBar; private TextView mHintView; public XListViewFooter(Context context) { super(context); initView(context); } public XListViewFooter(Context context, AttributeSet attrs) { super(context, attrs); initView(context); } public void setState(int state) { mHintView.setVisibility(View.INVISIBLE); mProgressBar.setVisibility(View.INVISIBLE); mHintView.setVisibility(View.INVISIBLE); if (state == STATE_READY) { mHintView.setVisibility(View.VISIBLE); mHintView.setText(R.string.xlistview_footer_hint_ready); } else if (state == STATE_LOADING) { mProgressBar.setVisibility(View.VISIBLE); } else { mHintView.setVisibility(View.VISIBLE); mHintView.setText(R.string.xlistview_footer_hint_normal); } } public void setBottomMargin(int height) { if (height < 0) return ; LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams)mContentView.getLayoutParams(); lp.bottomMargin = height; mContentView.setLayoutParams(lp); } public int getBottomMargin() { LinearLayout.LayoutParams lp = (LinearLayout.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() { LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams)mContentView.getLayoutParams(); lp.height = 0; mContentView.setLayoutParams(lp); } /** * show footer */ public void show() { LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams)mContentView.getLayoutParams(); lp.height = LayoutParams.WRAP_CONTENT; mContentView.setLayoutParams(lp); } private void initView(Context context) { mContext = context; LinearLayout moreView = (LinearLayout)LayoutInflater.from(mContext).inflate(R.layout.xlistview_footer, null); addView(moreView); moreView.setLayoutParams(new LinearLayout.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT)); mContentView = moreView.findViewById(R.id.xlistview_footer_content); mProgressBar = moreView.findViewById(R.id.xlistview_footer_progressbar); mHintView = (TextView)moreView.findViewById(R.id.xlistview_footer_hint_textview); } }
/** * @file XListViewHeader.java * @create Apr 18, 2012 5:22:27 PM * @author Maxwin * @description XListView's header */ package me.maxwin.view; import me.maxwin.R; import android.content.Context; import android.util.AttributeSet; import android.view.Gravity; import android.view.LayoutInflater; import android.view.View; import android.view.animation.Animation; import android.view.animation.RotateAnimation; import android.widget.ImageView; import android.widget.LinearLayout; import android.widget.ProgressBar; import android.widget.TextView; public class XListViewHeader extends LinearLayout { private LinearLayout mContainer; private ImageView mArrowImageView; private ProgressBar mProgressBar; private TextView mHintTextView; private int mState = STATE_NORMAL; private Animation mRotateUpAnim; private Animation mRotateDownAnim; private final int ROTATE_ANIM_DURATION = 180; public final static int STATE_NORMAL = 0; public final static int STATE_READY = 1; public final static int STATE_REFRESHING = 2; public XListViewHeader(Context context) { super(context); initView(context); } /** * @param context * @param attrs */ public XListViewHeader(Context context, AttributeSet attrs) { super(context, attrs); initView(context); } private void initView(Context context) { // 初始情况,设置下拉刷新view高度为0 LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams( LayoutParams.FILL_PARENT, 0); mContainer = (LinearLayout) LayoutInflater.from(context).inflate( R.layout.xlistview_header, null); addView(mContainer, lp); setGravity(Gravity.BOTTOM); mArrowImageView = (ImageView)findViewById(R.id.xlistview_header_arrow); mHintTextView = (TextView)findViewById(R.id.xlistview_header_hint_textview); mProgressBar = (ProgressBar)findViewById(R.id.xlistview_header_progressbar); mRotateUpAnim = new RotateAnimation(0.0f, -180.0f, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f); 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); } public void setState(int state) { if (state == mState) return ; if (state == STATE_REFRESHING) { // 显示进度 mArrowImageView.clearAnimation(); mArrowImageView.setVisibility(View.INVISIBLE); mProgressBar.setVisibility(View.VISIBLE); } else { // 显示箭头图片 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(R.string.xlistview_header_hint_normal); break; case STATE_READY: if (mState != STATE_READY) { mArrowImageView.clearAnimation(); mArrowImageView.startAnimation(mRotateUpAnim); mHintTextView.setText(R.string.xlistview_header_hint_ready); } break; case STATE_REFRESHING: mHintTextView.setText(R.string.xlistview_header_hint_loading); break; default: } mState = state; } public void setVisiableHeight(int height) { if (height < 0) height = 0; LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) mContainer .getLayoutParams(); lp.height = height; mContainer.setLayoutParams(lp); } public int getVisiableHeight() { return mContainer.getHeight(); } }
作者:chaoyu168 发表于2017/2/4 15:21:08 原文链接
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