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）