Android RecyclerView上下左右滑动表格布局

简介

使用RecyclerView实现网格布局，实现手机界面应用列表 ，基本逻辑实现，自定义可上下左右滑动的LayoutManager实现，item布局有两种实现方式，

XML布局文件

第一种直接固定一行显示多少，布局文件xml大小固定：

        

       ···

        

    

按行显示绑定对象；第二种实现每一个单元格的布局绑定：

LayoutManager 实现

创建继承自LinearLayoutManager的FormLayoutManger,并是现实LayoutManager的generateDefaultLayoutParams，确定RecyclerView作用域，

public class FormLayoutManger2 extends LinearLayoutManager {
    @Override
    public RecyclerView.LayoutParams generateDefaultLayoutParams() {
        return new RecyclerView.LayoutParams(RecyclerView.LayoutParams.WRAP_CONTENT, RecyclerView.LayoutParams.WRAP_CONTENT);
    }
}

重写onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state)，布局item布局展示方式，

// 按第一种实现方式，一行展示
@Override
    public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
        if (getItemCount() <= 0 || state.isPreLayout()) {
            return;
        }
        detachAndScrapAttachedViews(recycler);
       // 高度宽度统一，获取第一行大小数据，保存到List mItemFrames对象中
        View first = recycler.getViewForPosition(0);
        measureChildWithMargins(first, 0, 0);
        int width = getDecoratedMeasuredWidth(first);
        int height = getDecoratedMeasuredHeight(first);
        if (mItemFrames == null || mItemFrames.size() != getItemCount()) {
            mItemFrames = new ArrayList<>();
            for (int i = 0; i < getItemCount(); i++) {
                View scrap = recycler.getViewForPosition(i);
                addView(scrap);
                Rect rect = new Rect();
                rect.set(0, i * height, width, (i + 1) * height);
                mItemFrames.add(rect);
            }
        }
        mTotalWidth = Math.max(width, getHorizontallySpace());
        mTotalHeight = Math.max(getItemCount() * height, getVerticalSpace());
       // 获取到每一行单元格的宽高，添加到RecycleView中
        fill(recycler, state);
    }

// 按第二种实现方式，计算每个单元格的宽高，计算展示位置
@Override
    public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
        if (getItemCount() <= 0 || state.isPreLayout()) { return;}
        detachAndScrapAttachedViews(recycler);
        View first = recycler.getViewForPosition(0);
        measureChildWithMargins(first, 0, 0);
        int width = getDecoratedMeasuredWidth(first);
        int height = getDecoratedMeasuredHeight(first);
        //定义方向的偏移量
        int rows = -1;
        mItemFrames = new ArrayList<>();
        for (int i = 0; i < getItemCount(); i++) {
            int column = i % (spanCount);
            View scrap = recycler.getViewForPosition(i);
            addView(scrap);
            if (column == 0) {
                rows++;
            }
            Rect rect = new Rect();
            if (rows == 0) {
                rect.set(column * width, 0, (column + 1) * width, height);
            } else {
                rect.set(column * width, rows * height, (column + 1) * width, (rows + 1) * height);
            }
            mItemFrames.add(rect);
        }
        mTotalWidth = Math.max(spanCount * width, getHorizontallySpace());
        mTotalHeight = Math.max((rows + 1) * height, getVerticalSpace());
        fill(recycler, state);
    }

fill构建布局：

    private void fill(RecyclerView.Recycler recycler, RecyclerView.State state) {
        if (getItemCount() <= 0 || state.isPreLayout()) { return;}
        detachAndScrapAttachedViews(recycler);
        Rect displayRect = new Rect(mSumDx, mSumDy, getHorizontallySpace() + mSumDx, getVerticalSpace() + mSumDy);
        for (int i = 0; i < getItemCount(); i++) {
            Rect frame = mItemFrames.get(i);
            if (Rect.intersects(displayRect, frame)) {
                View scrap = recycler.getViewForPosition(i);
                addView(scrap);
                measureChildWithMargins(scrap, 0, 0);
                layoutDecorated(scrap, frame.left - mSumDx, frame.top - mSumDy, frame.right - mSumDx, frame.bottom - mSumDy);
            }
        }
    }

布局完成后实现它的滑动事件，实现上下左右滑动，重写canScrollHorizontally（），canScrollVertically（），返回ture,设置可上下左右滑动，然后根据求取的最大宽度和高度，设置滑动的最大高度和宽度，

@Override
    public boolean canScrollHorizontally() {
        return canHorizontallyScroll;
    }

    @Override
    public boolean canScrollVertically() {
        return canVerticallyScroll;
    }

    public void setCanHorizontallyScroll(boolean canHorizontallyScroll) {
        this.canHorizontallyScroll = canHorizontallyScroll;
    }

    public void setCanVerticallyScroll(boolean canVerticallyScroll) {
        this.canVerticallyScroll = canVerticallyScroll;
    }

    @Override
    public int scrollHorizontallyBy(int dx, RecyclerView.Recycler recycler, RecyclerView.State state) {
        int travel = dx;
        //如果滑动到最顶部
        if (mSumDx + dx < 0) {
            travel = -mSumDx;
        } else if (mSumDx + dx > mTotalWidth - getHorizontallySpace()) {
            //如果滑动到最底部
            travel = mTotalWidth - getHorizontallySpace() - mSumDx;
        }

        mSumDx += travel;
        // 平移容器内的item
        offsetChildrenHorizontal(-travel);
        fill(recycler, state);
        return dx;
    }

    @Override
    public int scrollVerticallyBy(int dy, RecyclerView.Recycler recycler, RecyclerView.State state) {
        int travel = dy;
        //如果滑动到最顶部
        if (mSumDy + dy < 0) {
            travel = -mSumDy;
        } else if (mSumDy + dy > mTotalHeight - getVerticalSpace()) {
            //如果滑动到最底部
            travel = mTotalHeight - getVerticalSpace() - mSumDy;
        }

        mSumDy += travel;
        // 平移容器内的item
        offsetChildrenVertical(-travel);
        fill(recycler, state);
        return dy;
    }

功能基本就完了 ，完整代码：

public class FormLayoutManger2 extends LinearLayoutManager {
    // 同步滑动时间
    private final List mRecyclerViews = new ArrayList<>();
    // 垂直滑动边界判断
    private int mSumDy = 0;
    private int mTotalHeight = 0;
    // 横向滑动边界判断
    private int mSumDx = 0;
    private int mTotalWidth = 0;

    private boolean canHorizontallyScroll = true;
    private boolean canVerticallyScroll = true;

    public FormLayoutManger2(Context context, RecyclerView... recyclerViews) {
        super(context);
        if (recyclerViews != null) {
            for (RecyclerView recyclerView : recyclerViews) {
                connectRecyclerView(recyclerView);
            }
        }
    }

    private SmartRefreshLayout refreshLayout;

    public void setRefreshLayout(SmartRefreshLayout refreshLayout) {
        this.refreshLayout = refreshLayout;
    }

    @Override
    public RecyclerView.LayoutParams generateDefaultLayoutParams() {
        return new RecyclerView.LayoutParams(RecyclerView.LayoutParams.WRAP_CONTENT, RecyclerView.LayoutParams.WRAP_CONTENT);
    }


    @Override
    public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
        if (getItemCount() <= 0 || state.isPreLayout()) {
            return;
        }
        detachAndScrapAttachedViews(recycler);
        View first = recycler.getViewForPosition(0);
        measureChildWithMargins(first, 0, 0);
        int width = getDecoratedMeasuredWidth(first);
        int height = getDecoratedMeasuredHeight(first);
        if (mItemFrames == null || mItemFrames.size() != getItemCount()) {
            mItemFrames = new ArrayList<>();
            for (int i = 0; i < getItemCount(); i++) {
                View scrap = recycler.getViewForPosition(i);
                addView(scrap);
                Rect rect = new Rect();
                rect.set(0, i * height, width, (i + 1) * height);
                mItemFrames.add(rect);
            }
        }
        mTotalWidth = Math.max(width, getHorizontallySpace());
        mTotalHeight = Math.max(getItemCount() * height, getVerticalSpace());
        fill(recycler, state);
    }

    private List mItemFrames = new ArrayList<>();

    private void fill(RecyclerView.Recycler recycler, RecyclerView.State state) {
        if (getItemCount() <= 0 || state.isPreLayout()) {
            return;
        }
        detachAndScrapAttachedViews(recycler);
        Rect displayRect = new Rect(mSumDx, mSumDy, getHorizontallySpace() + mSumDx, getVerticalSpace() + mSumDy);
        for (int i = 0; i < getItemCount(); i++) {
            Rect frame = mItemFrames.get(i);
            if (Rect.intersects(displayRect, frame)) {
                View scrap = recycler.getViewForPosition(i);
                addView(scrap);
                measureChildWithMargins(scrap, 0, 0);
                layoutDecorated(scrap, frame.left - mSumDx, frame.top - mSumDy, frame.right - mSumDx, frame.bottom - mSumDy);
            }
        }
    }

    @Override
    public boolean canScrollHorizontally() {
        return canHorizontallyScroll;
    }

    @Override
    public boolean canScrollVertically() {
        return canVerticallyScroll;
    }

    public void setCanHorizontallyScroll(boolean canHorizontallyScroll) {
        this.canHorizontallyScroll = canHorizontallyScroll;
    }

    public void setCanVerticallyScroll(boolean canVerticallyScroll) {
        this.canVerticallyScroll = canVerticallyScroll;
    }

    @Override
    public int scrollHorizontallyBy(int dx, RecyclerView.Recycler recycler, RecyclerView.State state) {
        int travel = dx;
        //如果滑动到最顶部
        if (mSumDx + dx < 0) {
            travel = -mSumDx;
        } else if (mSumDx + dx > mTotalWidth - getHorizontallySpace()) {
            //如果滑动到最底部
            travel = mTotalWidth - getHorizontallySpace() - mSumDx;
        }

        mSumDx += travel;
        // 平移容器内的item
        offsetChildrenHorizontal(-travel);
        fill(recycler, state);
        return dx;
    }

    @Override
    public int scrollVerticallyBy(int dy, RecyclerView.Recycler recycler, RecyclerView.State state) {
        int travel = dy;
        //如果滑动到最顶部
        if (mSumDy + dy < 0) {
            travel = -mSumDy;
        } else if (mSumDy + dy > mTotalHeight - getVerticalSpace()) {
            //如果滑动到最底部
            travel = mTotalHeight - getVerticalSpace() - mSumDy;
        }

        mSumDy += travel;
        // 平移容器内的item
        offsetChildrenVertical(-travel);
        fill(recycler, state);
        return dy;
    }

    private int getVerticalSpace() {
        return getHeight() - getPaddingBottom() - getPaddingTop();
    }

    private int getHorizontallySpace() {
        return getWidth() - getPaddingEnd() - getPaddingStart();
    }


    public void connectRecyclerView(RecyclerView recyclerView) {
        recyclerView.addOnScrollListener(mScrollListener);
        mRecyclerViews.add(recyclerView);
    }

    private final RecyclerView.OnScrollListener mScrollListener = new RecyclerView.OnScrollListener() {
        @Override
        public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int newState) {
            // 以下场景处理的是，滑动过程中手指松开，移到另外一个recyclerview进行滚动
            if (newState == RecyclerView.SCROLL_STATE_DRAGGING) {
                // 该recyclerview进入滚动状态的时候，其余四个要先停止滚动
                int currentIndex = mRecyclerViews.indexOf(recyclerView);
                for (int i = 0; i < mRecyclerViews.size(); i++) {
                    if (i != currentIndex) {
                        mRecyclerViews.get(i).stopScroll();
                    }
                }
            }
            if (refreshLayout != null) {
                if (mSumDy == 0) {
                    refreshLayout.setEnabled(true);
                } else {
                    refreshLayout.setEnabled(false);
                }
            }
        }

        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
            if (recyclerView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE) {
                // 手指所放在的当前recyclerview的下标
                int currentIndex = mRecyclerViews.indexOf(recyclerView);
                for (int i = 0; i < mRecyclerViews.size(); i++) {
                    if (i != currentIndex) {
                        mRecyclerViews.get(i).scrollBy(dx, dy);
                    }
                }
            }
        }
    };
}