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android recycleview 实现grideview并

android recycleview 实现grideview并

作者: hao_developer | 来源:发表于2020-04-19 10:42 被阅读0次
    image.png
    package com.outsource.live.view;
    
    import android.content.Context;
    import android.content.res.TypedArray;
    import android.graphics.Canvas;
    import android.graphics.Rect;
    import android.graphics.drawable.Drawable;
    import android.view.View;
    
    import androidx.recyclerview.widget.GridLayoutManager;
    import androidx.recyclerview.widget.RecyclerView;
    import androidx.recyclerview.widget.StaggeredGridLayoutManager;
    
    public class DividerGridItemDecoration extends RecyclerView.ItemDecoration {
    
        private static final int[] ATTRS = new int[] { android.R.attr.listDivider };
        private Drawable mDivider;
    
        public DividerGridItemDecoration(Context context) {
            final TypedArray a = context.obtainStyledAttributes(ATTRS);
            mDivider = a.getDrawable(0);
            a.recycle();
        }
    
        @Override
        public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
            drawHorizontal(c, parent);
            drawVertical(c, parent);
        }
    
        private int getSpanCount(RecyclerView parent) {
            // 列数
            int spanCount = -1;
            RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
            if (layoutManager instanceof GridLayoutManager) {
                spanCount = ((GridLayoutManager) layoutManager).getSpanCount();
            } else if (layoutManager instanceof StaggeredGridLayoutManager) {
                spanCount = ((StaggeredGridLayoutManager) layoutManager).getSpanCount();
            }
            return spanCount;
        }
    
        public void drawHorizontal(Canvas c, RecyclerView parent) {
            int childCount = parent.getChildCount();
            for (int i = 0; i < childCount; i++) {
                final View child = parent.getChildAt(i);
                final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
                final int left = child.getLeft() - params.leftMargin;
                final int right = child.getRight() + params.rightMargin + mDivider.getIntrinsicWidth();
                final int top = child.getBottom() + params.bottomMargin;
                final int bottom = top + mDivider.getIntrinsicHeight();
                mDivider.setBounds(left, top, right, bottom);
                mDivider.draw(c);
            }
        }
    
        public void drawVertical(Canvas c, RecyclerView parent) {
            final int childCount = parent.getChildCount();
            for (int i = 0; i < childCount; i++) {
                final View child = parent.getChildAt(i);
                final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
                final int top = child.getTop() - params.topMargin;
                final int bottom = child.getBottom() + params.bottomMargin;
                final int left = child.getRight() + params.rightMargin;
                final int right = left + mDivider.getIntrinsicWidth();
                mDivider.setBounds(left, top, right, bottom);
                mDivider.draw(c);
            }
        }
    
        private boolean isLastColum(RecyclerView parent, int pos, int spanCount, int childCount) {
            RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
            if (layoutManager instanceof GridLayoutManager) {
                // 如果是最后一列,则不需要绘制右边
                if ((pos + 1) % spanCount == 0) {
                    return true;
                }
            } else if (layoutManager instanceof StaggeredGridLayoutManager) {
                int orientation = ((StaggeredGridLayoutManager) layoutManager).getOrientation();
                if (orientation == StaggeredGridLayoutManager.VERTICAL) {
                    // 如果是最后一列,则不需要绘制右边
                    if ((pos + 1) % spanCount == 0){
                        return true;
                    }
                } else {
                    childCount = childCount - childCount % spanCount;
                    // 如果是最后一列,则不需要绘制右边
                    if (pos >= childCount)
                        return true;
                }
            }
            return false;
        }
    
        private boolean isLastRaw(RecyclerView parent, int pos, int spanCount, int childCount) {
            RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
            if (layoutManager instanceof GridLayoutManager) {
                childCount = childCount - childCount % spanCount;
                if (pos >= childCount)// 如果是最后一行,则不需要绘制底部
                    return true;
            } else if (layoutManager instanceof StaggeredGridLayoutManager) {
                int orientation = ((StaggeredGridLayoutManager) layoutManager).getOrientation();
                // StaggeredGridLayoutManager 且纵向滚动
                if (orientation == StaggeredGridLayoutManager.VERTICAL) {
                    childCount = childCount - childCount % spanCount;
                    // 如果是最后一行,则不需要绘制底部
                    if (pos >= childCount)
                        return true;
                } else {
                    // StaggeredGridLayoutManager 且横向滚动
                    // 如果是最后一行,则不需要绘制底部
                    if ((pos + 1) % spanCount == 0) {
                        return true;
                    }
                }
            }
            return false;
        }
    
        @Override
        public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
            int spanCount = getSpanCount(parent);
            int childCount = parent.getAdapter().getItemCount();
            // 如果是最后一行,则不需要绘制底部
            if (isLastRaw(parent, itemPosition, spanCount, childCount)) {
                outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
            } else if (isLastColum(parent, itemPosition, spanCount, childCount)) {
                // 如果是最后一列,则不需要绘制右边
                outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
            } else {
                outRect.set(0, 0, mDivider.getIntrinsicWidth(), mDivider.getIntrinsicHeight());
            }
        }
    }
    

    val layoutGirdManagerTwo = GridLayoutManager(this.activity, 2)
            layoutGirdManagerOne.setOrientation(GridLayout.VERTICAL)
            mallMenusTwoAdapter = MallMenusTwoAdapter(this.context!!, mallMenusList)
            mallMenusTwoAdapter?.setAdapterClickListener(this)
            with(rvMenuTwoList) {
                addItemDecoration(DividerGridItemDecoration(this.context))
                layoutManager = layoutGirdManagerTwo
                adapter = mallMenusTwoAdapter
            }
    

    使用
    \color{red}{addItemDecoration(DividerGridItemDecoration(this.context))}

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          本文标题:android recycleview 实现grideview并

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