为了让nj的回答更简单一点，你可以这样做:

public class DividerColorItemDecoration extends DividerItemDecoration {

    public DividerColorItemDecoration(Context context, int orientation) {
        super(context, orientation);
        setDrawable(ContextCompat.getDrawable(context, R.drawable.line_divider));
    }
}

所有这些答案都让我接近了答案，但它们都遗漏了一个关键细节。经过一番研究，我发现最简单的方法是将以下3个步骤结合起来:

使用支持库的DividerItemDecoration 用正确的颜色创建分隔线 在主题中设置这个分隔符为listDivider

步骤1:在配置RecyclerView时

recyclerView.addItemDecoration(
        new DividerItemDecoration(context, layoutManager.getOrientation()));

第二步:在res/drawable/divider_gray.xml这样的文件中

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <size android:width="1px" android:height="1px" />
    <solid android:color="@color/gray" />
</shape>

步骤3:在应用程序的主题

<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
    <!-- Other theme items above -->
    <item name="android:listDivider">@drawable/divider_gray</item>
</style>

编辑:更新跳过最后的分隔符: 在使用了一些之后，我意识到它在最后一项之后画了一个分隔符，这很烦人。所以我修改了第1步，如下所示，以覆盖在DividerItemDecoration的默认行为(当然，制作一个单独的类是另一种选择):

recyclerView.addItemDecoration(
        new DividerItemDecoration(context, layoutManager.getOrientation()) {
            @Override
            public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
                int position = parent.getChildAdapterPosition(view);
                // hide the divider for the last child
                if (position == parent.getAdapter().getItemCount() - 1) {
                    outRect.setEmpty();
                } else {
                    super.getItemOffsets(outRect, view, parent, state);
                }
            }
        }
);

所以这可能不是正确的方式，但我只是添加了一个视图到RecyclerView的单项视图(因为我不认为有一个内置的函数)，像这样:

<View
    android:layout_width="fill_parent"
    android:layout_height="@dimen/activity_divider_line_margin"
    android:layout_alignParentBottom="true"
    android:background="@color/tasklist_menu_dividerline_grey" />

这意味着每一项都有一行在底部填充。我把它做成1dp高，背景#111111。这也给了它一种“3D”效果。

我认为这是最简单的方法

mDividerItemDecoration = new DividerItemDecoration(recyclerView.getContext(),
                DividerItemDecoration.VERTICAL);
// or DividerItemDecoration.HORIZONTALL
        mDividerItemDecoration.setDrawable(getDrawable(R.drawable.myshape));
        recyclerView.addItemDecoration(mDividerItemDecoration);

注意:myshape可以是你想要做分隔的高度的矩形

下面是一个简单的自定义分割线(垂直分割线/ 1dp高度/黑色)的代码:

假设你有支持库:

compile "com.android.support:recyclerview-v7:25.1.1"

java代码

    DividerItemDecoration divider = new DividerItemDecoration(recyclerView.getContext(), DividerItemDecoration.VERTICAL);
    divider.setDrawable(ContextCompat.getDrawable(getBaseContext(), R.drawable.my_custom_divider));
    recyclerView.addItemDecoration(divider);

然后custom_divide .xml文件示例:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle">
    <size android:height="1dp" />
    <solid android:color="@android:color/black" />
</shape>

Bhuvanesh BS解决方案有效。Kotlin版本:

import android.graphics.Canvas
import android.graphics.drawable.Drawable
import androidx.recyclerview.widget.RecyclerView

class DividerItemDecorator(private val mDivider: Drawable?) : RecyclerView.ItemDecoration() {

    override fun onDraw(
        canvas: Canvas,
        parent: RecyclerView,
        state: RecyclerView.State
    ) {

        val dividerLeft = parent.paddingLeft
        val dividerRight = parent.width - parent.paddingRight
        for (i in 0 until parent.childCount - 1) {
            val child = parent.getChildAt(i)
            val dividerTop =
                child.bottom + (child.layoutParams as RecyclerView.LayoutParams).bottomMargin
            val dividerBottom = dividerTop + mDivider!!.intrinsicHeight
            mDivider.setBounds(dividerLeft, dividerTop, dividerRight, dividerBottom)
            mDivider.draw(canvas)
        }
    }
}