recyclerview可以通過addItemDecoration()方法實現新增自定義分割線的功能。比如需要實現如下圖功能

首先自己定義類繼承自RecyclerView.ItemDecoration

public class MyDividerDecoration extends RecyclerView.ItemDecoration {

    private static final int[] ATTRS = new int[]{
            android.R.attr.listDivider
    };

    /**
     * 用於繪製間隔樣式
     */
    private Drawable mDivider;

    public MyDividerDecoration(Context context) {
        // 獲取預設主題的屬性
        final TypedArray a = context.obtainStyledAttributes(ATTRS);
        mDivider = a.getDrawable(0);
        a.recycle();
    }


    @Override
    public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
        // 繪製間隔，每一個item，繪製右邊和下方間隔樣式
        int childCount = parent.getChildCount();
        int spanCount = ((GridLayoutManager)parent.getLayoutManager()).getSpanCount();
        int orientation = ((GridLayoutManager)parent.getLayoutManager()).getOrientation();
        boolean isDrawHorizontalDivider = true;
        boolean isDrawVerticalDivider = true;
        int extra = childCount % spanCount;
        extra = extra == 0 ? spanCount : extra;
        for(int i = 0; i < childCount; i++) {
            isDrawVerticalDivider = true;
            isDrawHorizontalDivider = true;
            // 如果是豎直方向，最右邊一列不繪製豎直方向的間隔
            if(orientation == OrientationHelper.VERTICAL && (i + 1) % spanCount == 0) {
                isDrawVerticalDivider = false;
            }

            // 如果是豎直方向，最後一行不繪製水平方向間隔
            if(orientation == OrientationHelper.VERTICAL && i >= childCount - extra) {
                isDrawHorizontalDivider = false;
            }

            // 如果是水平方向，最下面一行不繪製水平方向的間隔
            if(orientation == OrientationHelper.HORIZONTAL && (i + 1) % spanCount == 0) {
                isDrawHorizontalDivider = false;
            }

            // 如果是水平方向，最後一列不繪製豎直方向間隔
            if(orientation == OrientationHelper.HORIZONTAL && i >= childCount - extra) {
                isDrawVerticalDivider = false;
            }

            if(isDrawHorizontalDivider) {
                drawHorizontalDivider(c, parent, i);
            }

            if(isDrawVerticalDivider) {
                drawVerticalDivider(c, parent, i);
            }
        }
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        int spanCount = ((GridLayoutManager) parent.getLayoutManager()).getSpanCount();
        int orientation = ((GridLayoutManager)parent.getLayoutManager()).getOrientation();
        int position = parent.getChildLayoutPosition(view);
        if(orientation == OrientationHelper.VERTICAL && (position + 1) % spanCount == 0) {
            outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
            return;
        }

        if(orientation == OrientationHelper.HORIZONTAL && (position + 1) % spanCount == 0) {
            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
            return;
        }

        outRect.set(0, 0, mDivider.getIntrinsicWidth(), mDivider.getIntrinsicHeight());
    }

    /**
     * 繪製豎直間隔線
     *
     * @param canvas
     * @param parent
     *              父佈局，RecyclerView
     * @param position
     *              irem在父佈局中所在的位置
     */
    private void drawVerticalDivider(Canvas canvas, RecyclerView parent, int position) {
        final View child = parent.getChildAt(position);
        final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                .getLayoutParams();
        final int top = child.getTop() - params.topMargin;
        final int bottom = child.getBottom() + params.bottomMargin + mDivider.getIntrinsicHeight();
        final int left = child.getRight() + params.rightMargin;
        final int right = left + mDivider.getIntrinsicWidth();
        mDivider.setBounds(left, top, right, bottom);
        mDivider.draw(canvas);
    }

    /**
     * 繪製水平間隔線
     *
     * @param canvas
     * @param parent
     *              父佈局，RecyclerView
     * @param position
     *              item在父佈局中所在的位置
     */
    private void drawHorizontalDivider(Canvas canvas, RecyclerView parent, int position) {
        final View child = parent.getChildAt(position);
        final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                .getLayoutParams();
        final int top = child.getBottom() + params.bottomMargin;
        final int bottom = top + mDivider.getIntrinsicHeight();
        final int left = child.getLeft() - params.leftMargin;
        final int right = child.getRight() + params.rightMargin + mDivider.getIntrinsicWidth();
        mDivider.setBounds(left, top, right, bottom);
        mDivider.draw(canvas);
    }
}
 

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" >
    <solid android:color="@color/bg_gray"/>
    <size android:height="2dp" android:width="2dp"/>
</shape>

  <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
        <item name="android:listDivider">@drawable/my_divider</item>
    </style>
 

 recyclerview.addItemDecoration(new MyDividerDecoration(this));