我有一个非常简单的方法在RecyclerView中添加一个分隔符。使用自定义适配器修改回收器视图布局，然后与回收器视图项目一起添加带有背景色(将是分隔色)的线性布局，并添加1dp的高度(或根据您的要求)和宽度以匹配父级。

下面是一个示例代码。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical" android:layout_width="match_parent"
              android:layout_height="match_parent">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:padding="18dp">

        <TextView
            android:id="@+id/list_row_SNO"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight=".8"
            android:layout_gravity="end"
            android:text="44."
            android:textAlignment="center"
            android:textSize="24sp"
            android:textColor="@color/colorBlack"
            android:fontFamily="sans-serif-condensed" />

        <TextView
            android:id="@+id/list_row_Heading"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight=".2"
            android:layout_gravity="start"
            android:text="Student's application for leave and this what"
            android:textAlignment="textStart"
            android:textSize="24sp"
            android:textColor="@color/colorBlack"
            android:fontFamily="sans-serif-condensed" />

    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:background="@color/colorHighlight">
    </LinearLayout>

</LinearLayout>

请注意一下Alex Fu在GitHub上的这个文件: 链接

它是“直接从支持演示中提取”的diveritemdecoration .java示例文件。

在我的项目中导入这个文件后，我能够很好地获得分隔线，并将其作为项目装饰添加到回收器视图。

下面是我的onCreateView在我的片段中包含Recyclerview的样子:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_recycler_view, container, false);

    mRecyclerView = (RecyclerView) rootView.findViewById(R.id.my_recycler_view);
    mRecyclerView.addItemDecoration(new DividerItemDecoration(getActivity(), DividerItemDecoration.VERTICAL));

    mRecyclerView.setHasFixedSize(true);
    mLayoutManager = new LinearLayoutManager(getActivity());
    mRecyclerView.setLayoutManager(mLayoutManager);
    mRecyclerView.setItemAnimator(new DefaultItemAnimator());

    return rootView;
}

我确信可以做额外的造型，但这只是一个起点。：）

我在列表中添加了一行，如下所示:

<View
    android:id="@+id/divider"
    android:layout_width="match_parent"
    android:layout_height="1px"
    android:background="@color/dividerColor"/>

1px会画出细线。

如果你想隐藏最后一行的分隔符，那么使用separator . setvisibility (View.GONE);onBindViewHolder的最后一个列表项。

而不是创建一个形状xml来改变分隔线的高度和颜色，你可以通过编程来创建它:

val divider = DividerItemDecoration(
                  context,
                  DividerItemDecoration.VERTICAL)

divider.setDrawable(ShapeDrawable().apply {
    intrinsicHeight = resources.getDimensionPixelOffset(R.dimen.dp_15)
    paint.color = Color.RED // Note:
                            //   Currently (support version 28.0.0), we
                            //   can not use tranparent color here. If
                            //   we use transparent, we still see a
                            //   small divider line. So if we want
                            //   to display transparent space, we
                            //   can set color = background color
                            //   or we can create a custom ItemDecoration
                            //   instead of DividerItemDecoration.
})

recycler_devices.addItemDecoration(divider)

我觉得需要一个简单的、不使用XML的、基于代码的答案

DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(recyclerView.getContext(), DividerItemDecoration.VERTICAL);

ShapeDrawable shapeDrawableForDivider = new ShapeDrawable(new RectShape());

int dividerThickness = // (int) (SomeOtherView.getHeight() * desiredPercent);
shapeDrawableForDivider.setIntrinsicHeight(dividerThickness);
shapeDrawableForDivider.setAlpha(0);

dividerItemDecoration.setDrawable(shapeDrawableForDivider);

recyclerView.addItemDecoration(dividerItemDecoration);

我非常喜欢这个答案，我用Kotlin的单一表达式重新写了一遍:

    recyclerView.addItemDecoration(DividerItemDecoration(this,DividerItemDecoration.VERTICAL).also { deco ->
        with (ShapeDrawable(RectShape())){
            intrinsicHeight = (resources.displayMetrics.density * 24).toInt()
            alpha = 0
            deco.setDrawable(this)
        }
    })

这和@Nerdy最初的答案是一样的，只是它将分隔线的高度设置为24dp，而不是另一个视图高度的百分比。

我从一个旧的要点中分叉了DividerItemDecoration，并简化了它以适应我的用例，我还修改了它，以在ListView中绘制的方式绘制分隔符，包括在最后一个列表项之后的分隔符。这也会处理垂直的ItemAnimator动画:

1)将这个类添加到你的项目中:

public class DividerItemDecoration extends RecyclerView.ItemDecoration {
    private static final int[] ATTRS = new int[]{android.R.attr.listDivider};
    private Drawable divider;

    public DividerItemDecoration(Context context) {
        try {
            final TypedArray a = context.obtainStyledAttributes(ATTRS);
            divider = a.getDrawable(0);
            a.recycle();
        } catch (Resources.NotFoundException e) {
            // TODO Log or handle as necessary.
        }
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        super.getItemOffsets(outRect, view, parent, state);
        if (divider == null) return;
        if (parent.getChildAdapterPosition(view) < 1) return;

        if (getOrientation(parent) == LinearLayoutManager.VERTICAL)
            outRect.top = divider.getIntrinsicHeight();
        else
            throw new IllegalArgumentException("Only usable with vertical lists");
    }

    @Override
    public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
        if (divider == null) {
            super.onDrawOver(c, parent, state);
            return;
        }

        final int left = parent.getPaddingLeft();
        final int right = parent.getWidth() - parent.getPaddingRight();
        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 size = divider.getIntrinsicHeight();
            final int top = (int) (child.getTop() - params.topMargin - size + child.getTranslationY());
            final int bottom = top + size;
            divider.setBounds(left, top, right, bottom);
            divider.draw(c);

            if (i == childCount - 1) {
                final int newTop = (int) (child.getBottom() + params.bottomMargin + child.getTranslationY());
                final int newBottom = newTop + size;
                divider.setBounds(left, newTop, right, newBottom);
                divider.draw(c);
            }
        }
    }

    private int getOrientation(RecyclerView parent) {
        if (!(parent.getLayoutManager() instanceof LinearLayoutManager))
            throw new IllegalStateException("Layout manager must be an instance of LinearLayoutManager");
        return ((LinearLayoutManager) parent.getLayoutManager()).getOrientation();
    }
}

2)添加装饰器到你的RecylerView:

recyclerView.addItemDecoration(new DividerItemDecoration(getActivity()));