PullToRefreshScrollView 嵌套RecyclerView实现特卖列表倒计时抢购

来源：互联网发布：手机淘宝刷手接单软件编辑：程序博客网时间：2024/04/30 18:15

不久之前，我们谈到了通过Handler与timer及TimerTask结合实现倒计时抢购列表，那个是PullToRefreshListView实现的，今天要讲的是PullToRefreshScrollView 嵌套RecyclerView实现的抢购首页功能，相信在很多的app中都有实现的，不过我们知道特别是这种嵌套，滑动和计算高度的时候是各种冲突的，PullToRefreshScrollView 嵌套RecyclerView会有焦点的获取问题，好，今天就实现这么一个功能。之前的功能请访问：点击打开链接

先上一张效果图：

为了方便大家的理解，我将上面的两个子模块封装成了一个组件，我们今天只对下面的实现进行讲解。

首先这里倒计时写在子线程就不说了，还有就是用RecycleView而不用ListView这也不多说了，这方面比较的文章比较多，但是我在版本5.0的时候遇到一夜问题，就是RecyclerView的高度计算不出来，这里之前面试别人的时候也说过，这里不是对RecycleView的OnMeasure（）重写，而是需要设置RecycleView的layoutManager，比如是要实现ListView的线性效果，就需要增加下面的Layoutparam.

public class WrapLinearLayoutManager extends LinearLayoutManager {    public WrapLinearLayoutManager(Context context) {        super(context);    }    public WrapLinearLayoutManager(Context context, int orientation, boolean reverseLayout) {        super(context, orientation, reverseLayout);    }    private int[] mMeasuredDimension = new int[2];    @Override    public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state,                          int widthSpec, int heightSpec) {        final int widthMode = View.MeasureSpec.getMode(widthSpec);        final int heightMode = View.MeasureSpec.getMode(heightSpec);        final int widthSize = View.MeasureSpec.getSize(widthSpec);        final int heightSize = View.MeasureSpec.getSize(heightSpec);        int width = 0;        int height = 0;        for (int i = 0; i < getItemCount(); i++) {            measureScrapChild(recycler, i,                    View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),                    View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),                    mMeasuredDimension);            if (getOrientation() == HORIZONTAL) {                width = width + mMeasuredDimension[0];                if (i == 0) {                    height = mMeasuredDimension[1];                }            } else {                height = height + mMeasuredDimension[1];                if (i == 0) {                    width = mMeasuredDimension[0];                }            }        }        switch (widthMode) {            case View.MeasureSpec.EXACTLY:                width = widthSize;            case View.MeasureSpec.AT_MOST:            case View.MeasureSpec.UNSPECIFIED:        }        switch (heightMode) {            case View.MeasureSpec.EXACTLY:                height = heightSize;            case View.MeasureSpec.AT_MOST:            case View.MeasureSpec.UNSPECIFIED:        }        setMeasuredDimension(width, height);    }    private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec,                                   int heightSpec, int[] measuredDimension) {        try {            View view = recycler.getViewForPosition(0);//fix 动态添加时报IndexOutOfBoundsException            if (view != null) {                RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) view.getLayoutParams();                int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec,                        getPaddingLeft() + getPaddingRight(), p.width);                int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec,                        getPaddingTop() + getPaddingBottom(), p.height);                view.measure(childWidthSpec, childHeightSpec);                measuredDimension[0] = view.getMeasuredWidth() + p.leftMargin + p.rightMargin;                measuredDimension[1] = view.getMeasuredHeight() + p.bottomMargin + p.topMargin;                recycler.recycleView(view);            }        } catch (Exception e) {            e.printStackTrace();        } finally {        }    }    @Override    public boolean canScrollVertically() {        return false;    }}

如果是要实现Grid的效果，需要设置，这个GridLayoutManager系统帮我们实现了

public class WrapGridLayoutManager extends GridLayoutManager {    private int mwidth = 0;    private int mheight = 0;     public WrapGridLayoutManager(Context context, int spanCount) {        super(context, spanCount);    }     public WrapGridLayoutManager((Context context, int spanCount,            int orientation, boolean reverseLayout) {        super(context, spanCount, orientation, reverseLayout);    }     private int[] mMeasuredDimension = new int[2];     public int getMwidth() {        return mwidth;    }     public void setMwidth(int mwidth) {        this.mwidth = mwidth;    }     public int getMheight() {        return mheight;    }     public void setMheight(int mheight) {        this.mheight = mheight;    }     @Override    public void onMeasure(RecyclerView.Recycler recycler,            RecyclerView.State state, int widthSpec, int heightSpec) {        final int widthMode = View.MeasureSpec.getMode(widthSpec);        final int heightMode = View.MeasureSpec.getMode(heightSpec);        final int widthSize = View.MeasureSpec.getSize(widthSpec);        final int heightSize = View.MeasureSpec.getSize(heightSpec);         int width = 0;        int height = 0;        int count = getItemCount();        int span = getSpanCount();        for (int i = 0; i < count; i++) {            measureScrapChild(recycler, i, View.MeasureSpec.makeMeasureSpec(i,                    View.MeasureSpec.UNSPECIFIED),                    View.MeasureSpec.makeMeasureSpec(i,                            View.MeasureSpec.UNSPECIFIED), mMeasuredDimension);             if (getOrientation() == HORIZONTAL) {                if (i % span == 0) {                    width = width + mMeasuredDimension[0];                }                if (i == 0) {                    height = mMeasuredDimension[1];                }            } else {                if (i % span == 0) {                    height = height + mMeasuredDimension[1];                }                if (i == 0) {                    width = mMeasuredDimension[0];                }            }        }         switch (widthMode) {        case View.MeasureSpec.EXACTLY:            width = widthSize;        case View.MeasureSpec.AT_MOST:        case View.MeasureSpec.UNSPECIFIED:        }         switch (heightMode) {        case View.MeasureSpec.EXACTLY:            height = heightSize;        case View.MeasureSpec.AT_MOST:        case View.MeasureSpec.UNSPECIFIED:        }        setMheight(height);        setMwidth(width);        setMeasuredDimension(width, height);    }     private void measureScrapChild(RecyclerView.Recycler recycler,            int position, int widthSpec, int heightSpec, int[] measuredDimension) {        if (position < getItemCount()) {            try {                View view = recycler.getViewForPosition(0);// fix                                                            // 鍔ㄦ?佹坊鍔犳椂鎶ndexOutOfBoundsException                if (view != null) {                    this.measureChild(view, 0, 0);                    measuredDimension[0] = this.getDecoratedMeasuredWidth(view);                    measuredDimension[1] = this.getDecoratedMeasuredHeight(view);                    recycler.recycleView(view);                }            } catch (Exception e) {                e.printStackTrace();            }        }    }         public static class SpacesItemDecoration extends RecyclerView.ItemDecoration {          private int space;           public SpacesItemDecoration(int space) {            this.space = space;          }           @Override          public void getItemOffsets(Rect outRect, View view,               RecyclerView parent, RecyclerView.State state) {            outRect.left = space;            outRect.right = space;            outRect.bottom = space;            outRect.top = space;             // Add top margin only for the first item to avoid double space between items//          if(parent.getChildLayoutPosition(view) == 0)          }        }}

recyclerView.setLayoutManager(new GridLayoutManager(getActivity(), 2));

要解决PullToRefreshScrollView和RecyclerView我尝试了，通过OnIntercetor事件拦截，不起作用，最后只需要在RecycleView设置下面一段话就好了。

 LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity(), LinearLayoutManager.VERTICAL, false) {            @Override            public boolean canScrollVertically() {                return false;            }        };        recyclerView.setLayoutManager(linearLayoutManager);

最后附上代码的下载地址点击打开链接，欢迎留言（加群：278792776）

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