Android仿QQ联系人分组悬停 - PinnedHeaderListView

看效果：

配合pullrefresh还能做到下拉刷新，已实现（亲测）。

直接上源码：

/**
 * Created by carson on 2017/11/14.
 * 实现了分组悬停group header
 * @since 1.1.4
 */

public class PinnedExHeaderListview extends ExpandableListView implements AbsListView.OnScrollListener {

    private HeaderListener mHeadListener;
    /**
     * 用于在列表头显示的 View,mHeaderViewVisible 为 true 才可见
     */
    private View mHeaderView;
    /**
     * 列表头是否可见
     */
    private boolean mHeaderViewVisible;
    private int mHeaderViewWidth;
    private int mHeaderViewHeight;

    public PinnedExHeaderListview(Context context) {
        super(context);
    }

    public interface HeaderListener {
        public static final int PINNED_HEADER_GONE = 0;
        public static final int PINNED_HEADER_VISIBLE = 1;
        public static final int PINNED_HEADER_PUSHED_UP = 2;

        /**
         * 获取 Header 的状态
         *
         * @param groupPosition
         * @param childPosition
         * @return PINNED_HEADER_GONE, PINNED_HEADER_VISIBLE, PINNED_HEADER_PUSHED_UP
         * 其中之一
         */
        int getHeaderState(int groupPosition, int childPosition);

        /**
         * @param header
         * @param groupPosition
         * @param childPosition
         */
        void updateHeader(View header, int groupPosition, int childPosition);

    }


    public void initHeaderView(View view) {
        mHeaderView = view;
        if (mHeaderView != null) {
            AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
                    ViewGroup.LayoutParams.MATCH_PARENT,
                    ViewGroup.LayoutParams.WRAP_CONTENT);
            view.setLayoutParams(lp);
            setFadingEdgeLength(0);
        }
    }


    public void setHeaderViewListener(HeaderListener listener) {
        this.mHeadListener = listener;
        setOnScrollListener(this);
    }

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

    }

    @Override
    public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
        if (mHeaderView != null) {
            long flatPos = getExpandableListPosition(firstVisibleItem);
            int groupPosition = ExpandableListView.getPackedPositionGroup(flatPos);
            int childPosition = ExpandableListView.getPackedPositionChild(flatPos);
            configureHeaderView(groupPosition, childPosition);
        }
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        if (mHeaderView!=null){
            int x = (int) ev.getX();
            int y = (int) ev.getY();
            int pos = pointToPosition(x, y);
            if (y >= mHeaderView.getTop() && y <= mHeaderView.getBottom()) {
               if (ev.getAction() == MotionEvent.ACTION_UP) {
                    int groupPosition = getPackedPositionGroup(getExpandableListPosition(pos));
                    System.out.println("this is :"+ groupPosition +getExpandableListAdapter().getGroup(groupPosition).toString());
                    if (groupPosition != INVALID_POSITION) {
                        int point = mHeaderView.getWidth()-x;
                        if(point< Utils.convertDpToPixel(70)&&point>Utils.convertDpToPixel(15)){
                            ToastUtil.showMessage("icon click"+groupPosition);
                        }
//                        if (isGroupExpanded(groupPosition)) {
//                            collapseGroup(groupPosition);
//                        } else {
//                            expandGroup(groupPosition);
//                        }
                    }
                }
                return true;
            }
        }
        return super.dispatchTouchEvent(ev);
    }
    private float mDownX;
    private float mDownY;

    /**
     * 如果 HeaderView 是可见的 , 此函数用于判断是否点击了 HeaderView, 并对做相应的处理 , 因为 HeaderView
     * 是画上去的 , 所以设置事件监听是无效的 , 只有自行控制 .
     */
//    @Override
//    public boolean onTouchEvent(MotionEvent ev) {
//        if (mHeaderViewVisible) {
//            switch (ev.getAction()) {
//                case MotionEvent.ACTION_DOWN:
//                    mDownX = ev.getX();
//                    mDownY = ev.getY();
//                    if (mDownX <= mHeaderViewWidth && mDownY <= mHeaderViewHeight) {
//                        return true;
//                    }
//                    break;
//                case MotionEvent.ACTION_UP:
//                    float x = ev.getX();
//                    float y = ev.getY();
//                    float offsetX = Math.abs(x - mDownX);
//                    float offsetY = Math.abs(y - mDownY);
//                    // 如果 HeaderView 是可见的 , 点击在 HeaderView 内 , 那么触发 headerClick()
//                    if (x <= mHeaderViewWidth && y <= mHeaderViewHeight
//                            && offsetX <= mHeaderViewWidth
//                            && offsetY <= mHeaderViewHeight) {
//                        if (mHeaderView != null) {
//                            headerViewClick();
//                        }
//                        return true;
//                    }
//                    break;
//                default:
//                    break;
//            }
//        }
//        return super.onTouchEvent(ev);
//    }

    /**
     * 点击 HeaderView 触发的事件
     */
    private void headerViewClick() {
        long packedPosition = getExpandableListPosition(this
                .getFirstVisiblePosition());
        int groupPosition = ExpandableListView
                .getPackedPositionGroup(packedPosition);
        this.collapseGroup(groupPosition);
        this.setSelectedGroup(groupPosition);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        if (mHeaderView != null) {
            measureChild(mHeaderView, widthMeasureSpec, heightMeasureSpec);
            mHeaderViewWidth = mHeaderView.getMeasuredWidth();
            mHeaderViewHeight = mHeaderView.getMeasuredHeight();
        }
    }

    private int mOldState = -1;

    @Override
    protected void onLayout(boolean changed, int left, int top, int right,
                            int bottom) {
        super.onLayout(changed, left, top, right, bottom);

        if (this.mHeadListener != null) {
            long flatPostion = getExpandableListPosition(getFirstVisiblePosition());
            int groupPos = ExpandableListView
                    .getPackedPositionGroup(flatPostion);
            int childPos = ExpandableListView
                    .getPackedPositionChild(flatPostion);
            int state = this.mHeadListener.getHeaderState(groupPos, childPos);
            if (mHeaderView != null && state != mOldState) {
                mOldState = state;
                mHeaderView.layout(0, 0, mHeaderViewWidth, mHeaderViewHeight);
            }
            configureHeaderView(groupPos, childPos);
        }
    }

    public void configureHeaderView(int groupPosition, int childPosition) {
        if (groupPosition == -1 || mHeaderView == null || this.mHeadListener == null || getExpandableListAdapter().getGroupCount() == 0) {
            return;
        }
        int state = mHeadListener.getHeaderState(groupPosition, childPosition);
        switch (state) {
            case HeaderListener.PINNED_HEADER_GONE: {
                mHeaderViewVisible = false;
                break;
            }

            case HeaderListener.PINNED_HEADER_VISIBLE: {
                mHeadListener.updateHeader(mHeaderView, groupPosition,
                        childPosition);

                if (mHeaderView.getTop() != 0) {
                    mHeaderView.layout(0, 0, mHeaderViewWidth, mHeaderViewHeight);
                }

                mHeaderViewVisible = true;
                break;
            }

            case HeaderListener.PINNED_HEADER_PUSHED_UP: {
                View firstView = getChildAt(0);
                int bottom = firstView.getBottom();

                // intitemHeight = firstView.getHeight();
                int headerHeight = mHeaderView.getHeight();

                int y;
                if (bottom < headerHeight) {
                    y = (bottom - headerHeight);
//                    alpha = MAX_ALPHA * (headerHeight + y) / headerHeight;
                } else {
                    y = 0;
                }

                mHeadListener.updateHeader(mHeaderView, groupPosition,
                        childPosition);

                if (mHeaderView.getTop() != y) {
                    mHeaderView.layout(0, y, mHeaderViewWidth, mHeaderViewHeight
                            + y);
                }
                mHeaderViewVisible = true;
                break;
            }
        }
    }

    @Override
    /**
     * 列表界面更新时调用该方法(如滚动时)
     */
    protected void dispatchDraw(Canvas canvas) {
        super.dispatchDraw(canvas);
        if (mHeaderViewVisible && mHeaderView != null) {
            // 分组栏是直接绘制到界面中，而不是加入到ViewGroup中
            drawChild(canvas, mHeaderView, getDrawingTime());
        }
    }
}

使用注意事项：

R.layout.item_group_root为分组的view，就是悬停时的view

  //support group header floatting
        pinnedListview.initHeaderView(getLayoutInflater().inflate(R.layout.item_group_root, groupExpandablelist, false));
        pinnedListview.setHeaderViewListener(new PinnedExHeaderListview.HeaderListener() {
            @Override
            public int getHeaderState(int groupPosition, int childPosition) {
                if (groupPosition == -1) {
                    return PINNED_HEADER_GONE;
                }
                int childCount = adapter.getChildrenCount(groupPosition);
                if (childPosition == childCount - 1) {
                    return PINNED_HEADER_PUSHED_UP;
                } else if (childPosition == -1
                        && !pinnedListview.isGroupExpanded(groupPosition)) {
                    return PINNED_HEADER_GONE;
                } else {
                    return PINNED_HEADER_VISIBLE;
                }
            }

            @Override
            public void updateHeader(View header, int groupPosition, int childPosition) {
                if (groupPosition > -1) {
                    TextView group = (TextView) header.findViewById(R.id.root_name);
                    if (group != null) {
                        group.setText(adapter.getGroup(groupPosition).getModule_name());
                    }
                }
            }
        });