实例介绍
【实例简介】Android ListView 下拉刷新 上拉更多
【实例截图】
【核心代码】
【实例截图】
【核心代码】
public class ScrollOverListView extends ListView implements OnScrollListener { private int mLastY; private int mBottomPosition; private static final String TAG = "listview"; /**松开更新**/ private final static int RELEASE_To_REFRESH = 0; /**下拉更新**/ private final static int PULL_To_REFRESH = 1; /**更新中**/ private final static int REFRESHING = 2; /**无**/ private final static int DONE = 3; /**加载中**/ private final static int LOADING = 4; /**实际的padding的距离与界面上偏移距离的比例**/ private final static int RATIO = 3; private LayoutInflater inflater; /**头部刷新的布局**/ private LinearLayout headView; /**头部显示下拉刷新等的控件**/ private TextView tipsTextview; /**刷新控件**/ private TextView lastUpdatedTextView; /**箭头图标**/ private ImageView arrowImageView; /**头部滚动条**/ private ProgressBar progressBar; /**显示动画**/ private RotateAnimation animation; /**头部回退显示动画**/ 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; /**头部高度**/ private int headContentHeight; /**开始的Y坐标**/ private int startY; /**第一个item**/ private int firstItemIndex; /**状态**/ private int state; private boolean isBack; /**是否要使用下拉刷新功能**/ public boolean showRefresh = true; public static boolean canRefleash = true; public ScrollOverListView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); init(context); } public ScrollOverListView(Context context, AttributeSet attrs) { super(context, attrs); init(context); } public ScrollOverListView(Context context) { super(context); init(context); } /**出事化控件**/ private void init(Context context) { mBottomPosition = 0; setCacheColorHint(0); inflater = LayoutInflater.from(context); headView = (LinearLayout) inflater.inflate(R.layout.pull_down_head, null); arrowImageView = (ImageView) headView .findViewById(R.id.head_arrowImageView); arrowImageView.setMinimumWidth(70); 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); measureView(headView); headContentHeight = headView.getMeasuredHeight(); headView.setPadding(0, -1 * headContentHeight, 0, 0); headView.invalidate(); /**列表添加头部**/ addHeaderView(headView, null, false); setOnScrollListener(this); animation = new RotateAnimation(0, -180, RotateAnimation.RELATIVE_TO_SELF, 0.5f, RotateAnimation.RELATIVE_TO_SELF, 0.5f); animation.setInterpolator(new LinearInterpolator()); animation.setDuration(250); animation.setFillAfter(true); reverseAnimation = new RotateAnimation(-180, 0, RotateAnimation.RELATIVE_TO_SELF, 0.5f, RotateAnimation.RELATIVE_TO_SELF, 0.5f); reverseAnimation.setInterpolator(new LinearInterpolator()); reverseAnimation.setDuration(200); reverseAnimation.setFillAfter(true); state = DONE; } /**触摸事件的处理**/ @Override public boolean onTouchEvent(MotionEvent ev) { final int action = ev.getAction(); final int y = (int) ev.getRawY(); cancelLongPress(); switch (action) { case MotionEvent.ACTION_DOWN: { //按下的时候 if (firstItemIndex == 0 && !isRecored) { isRecored = true; startY = (int) ev.getY(); Log.v(TAG, "在down时候记录当前位置‘"); } // =========================== mLastY = y; final boolean isHandled = mOnScrollOverListener.onMotionDown(ev); if (isHandled) { mLastY = y; return isHandled; } break; } case MotionEvent.ACTION_MOVE: { //手指正在移动的时候 int tempY = (int) ev.getY(); if (showRefresh) { if (!isRecored && firstItemIndex == 0) { Log.v(TAG, "在move时候记录下位置"); isRecored = true; startY = tempY; } if (state != REFRESHING && isRecored && state != LOADING) { // 保证在设置padding的过程中,当前的位置一直是在head,否则如果当列表超出屏幕的话,当在上推的时候,列表会同时进行滚动 // 可以松手去刷新了 if (state == RELEASE_To_REFRESH) { setSelection(0); // 往上推了,推到了屏幕足够掩盖head的程度,但是还没有推到全部掩盖的地步 if (((tempY - startY) / RATIO < headContentHeight) && (tempY - startY) > 0) { state = PULL_To_REFRESH; changeHeaderViewByState(); } // 一下子推到顶了 else if (tempY - startY <= 0) { state = DONE; changeHeaderViewByState(); Log.v(TAG, "由松开刷新状态转变到done状态"); } // 往下拉了,或者还没有上推到屏幕顶部掩盖head的地步 else { // 不用进行特别的操作,只用更新paddingTop的值就行了 } } // 还没有到达显示松开刷新的时候,DONE或者是PULL_To_REFRESH状态 if (state == PULL_To_REFRESH) { setSelection(0); // 下拉到可以进入RELEASE_TO_REFRESH的状态 if ((tempY - startY) / RATIO >= headContentHeight) { state = RELEASE_To_REFRESH; isBack = true; changeHeaderViewByState(); Log.v(TAG, "由done或者下拉刷新状态转变到松开刷新"); } // 上推到顶了 else if (tempY - startY <= 0) { state = DONE; changeHeaderViewByState(); Log.v(TAG, "由DOne或者下拉刷新状态转变到done状态"); } } // done状态下 if (state == DONE) { if (tempY - startY > 0) { state = PULL_To_REFRESH; changeHeaderViewByState(); } } // 更新headView的size if (state == PULL_To_REFRESH) { headView.setPadding(0, -1 * headContentHeight (tempY - startY) / RATIO, 0, 0); } // 更新headView的paddingTop if (state == RELEASE_To_REFRESH) { headView.setPadding(0, (tempY - startY) / RATIO - headContentHeight, 0, 0); } } } // ============================================== final int childCount = getChildCount(); if (childCount == 0) return super.onTouchEvent(ev); final int itemCount = getAdapter().getCount() - mBottomPosition; final int deltaY = y - mLastY; final int lastBottom = getChildAt(childCount - 1).getBottom(); final int end = getHeight() - getPaddingBottom(); final int firstVisiblePosition = getFirstVisiblePosition(); final boolean isHandleMotionMove = mOnScrollOverListener .onMotionMove(ev, deltaY); if (isHandleMotionMove) { mLastY = y; return true; } /** 到达底部 * 到达底部的事件在另外一个类执行**/ if (firstVisiblePosition childCount >= itemCount && lastBottom <= end && deltaY < 0) { final boolean isHandleOnListViewBottomAndPullDown; isHandleOnListViewBottomAndPullDown = mOnScrollOverListener .onListViewBottomAndPullUp(deltaY); if (isHandleOnListViewBottomAndPullDown) { mLastY = y; return true; } } break; } case MotionEvent.ACTION_UP: { //手指抬起来的时候 if (state != REFRESHING && state != LOADING) { if (state == DONE) { // 什么都不做 } if (state == PULL_To_REFRESH) { state = DONE; changeHeaderViewByState(); Log.v(TAG, "由下拉刷新状态,到done状态"); } if (state == RELEASE_To_REFRESH) { state = REFRESHING; changeHeaderViewByState(); canRefleash = true; Log.v(TAG, "由松开刷新状态,到done状态"); } } isRecored = false; isBack = false; // /====================== final boolean isHandlerMotionUp = mOnScrollOverListener .onMotionUp(ev); if (isHandlerMotionUp) { mLastY = y; return true; } break; } } mLastY = y; return super.onTouchEvent(ev); } /** 空的 */ private OnScrollOverListener mOnScrollOverListener = new OnScrollOverListener() { @Override public boolean onListViewTopAndPullDown(int delta) { return false; } @Override public boolean onListViewBottomAndPullUp(int delta) { return false; } @Override public boolean onMotionDown(MotionEvent ev) { return false; } @Override public boolean onMotionMove(MotionEvent ev, int delta) { return false; } @Override public boolean onMotionUp(MotionEvent ev) { return false; } }; // =============================== public method /** * 可以自定义其中一个条目为头部,头部触发的事件将以这个为准,默认为第一个 * * @param index 正数第几个,必须在条目数范围之内 */ public void setTopPosition(int index) { if (getAdapter() == null) throw new NullPointerException( "You must set adapter before setTopPosition!"); if (index < 0) throw new IllegalArgumentException("Top position must > 0"); } /** * 可以自定义其中一个条目为尾部,尾部触发的事件将以这个为准,默认为最后一个 * * @param index 倒数第几个,必须在条目数范围之内 */ public void setBottomPosition(int index) { if (getAdapter() == null) throw new NullPointerException( "You must set adapter before setBottonPosition!"); if (index < 0) throw new IllegalArgumentException("Bottom position must > 0"); mBottomPosition = index; } /** * 设置这个Listener可以监听是否到达顶端,或者是否到达低端等事件</br> * * @see OnScrollOverListener */ public void setOnScrollOverListener( OnScrollOverListener onScrollOverListener) { mOnScrollOverListener = onScrollOverListener; } /** * 滚动监听接口 * * @see ScrollOverListView#setOnScrollOverListener(OnScrollOverListener) * */ public interface OnScrollOverListener { /** * 到达最顶部触发 * * @param delta * 手指点击移动产生的偏移量 * @return */ boolean onListViewTopAndPullDown(int delta); /** * 到达最底部触发 * * @param delta * 手指点击移动产生的偏移量 * @return */ boolean onListViewBottomAndPullUp(int delta); /** * 手指触摸按下触发,相当于{@link MotionEvent#ACTION_DOWN} * * @return 返回true表示自己处理 * @see View#onTouchEvent(MotionEvent) */ boolean onMotionDown(MotionEvent ev); /** * 手指触摸移动触发,相当于{@link MotionEvent#ACTION_MOVE} * * @return 返回true表示自己处理 * @see View#onTouchEvent(MotionEvent) */ boolean onMotionMove(MotionEvent ev, int delta); /** * 手指触摸后提起触发,相当于{@link MotionEvent#ACTION_UP} * * @return 返回true表示自己处理 * @see View#onTouchEvent(MotionEvent) */ boolean onMotionUp(MotionEvent ev); } @Override public void onScroll(AbsListView arg0, int firstVisiableItem, int arg2, int arg3) { firstItemIndex = firstVisiableItem; } @Override public void onScrollStateChanged(AbsListView view, int scrollState) { } // 此方法直接照搬自网络上的一个下拉刷新的demo,此处是“估计”headView的width以及height 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); } public void onRefreshComplete() { state = DONE; lastUpdatedTextView.setText("最近更新:" new Date().toLocaleString()); changeHeaderViewByState(); } // 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("松开刷新"); Log.v(TAG, "当前状态,松开刷新"); break; case PULL_To_REFRESH: progressBar.setVisibility(View.GONE); tipsTextview.setVisibility(View.VISIBLE); lastUpdatedTextView.setVisibility(View.VISIBLE); arrowImageView.clearAnimation(); arrowImageView.setVisibility(View.VISIBLE); // 是由RELEASE_To_REFRESH状态转变来的 if (isBack) { isBack = false; arrowImageView.clearAnimation(); arrowImageView.startAnimation(reverseAnimation); tipsTextview.setText("下拉刷新"); } else { tipsTextview.setText("下拉刷新"); } Log.v(TAG, "当前状态,下拉刷新"); break; case REFRESHING: headView.setPadding(0, 0, 0, 0); progressBar.setVisibility(View.VISIBLE); arrowImageView.clearAnimation(); arrowImageView.setVisibility(View.GONE); tipsTextview.setText("正在刷新..."); lastUpdatedTextView.setVisibility(View.VISIBLE); Log.v(TAG, "当前状态,正在刷新..."); break; case DONE: headView.setPadding(0, -1 * headContentHeight, 0, 0); progressBar.setVisibility(View.GONE); arrowImageView.clearAnimation(); arrowImageView.setImageResource(R.drawable.pull_down_arrow); tipsTextview.setText("下拉刷新"); lastUpdatedTextView.setVisibility(View.VISIBLE); Log.v(TAG, "当前状态,done"); break; } } }
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