为视图添加边距。这对我很管用。

android:layout_marginTop="10dp"

如果你只是想在XML中添加相等的间距，只需在RecyclerView中设置padding，并在你膨胀到RecyclerView中的项目中设置等量的layoutMargin，并让背景颜色决定间距颜色。

只需添加

recyclerView.addItemDecoration(new DividerItemDecoration(getContext(),
                DividerItemDecoration.VERTICAL));

此外，您可能还需要添加依赖项 实现“com.android.support: recyclerview-v7:28.0.0”

为了自定义它，你可以添加一个自定义drawable:

DividerItemDecoration itemDecorator = new DividerItemDecoration(getContext(), DividerItemDecoration.VERTICAL);
itemDecorator.setDrawable(ContextCompat.getDrawable(getContext(), R.drawable.divider));

你可以自由地使用任何自定义绘图，例如:

<shape xmlns:android="http://schemas.android.com/apk/res/android"
       android:shape="rectangle">
    <solid android:color="@color/colorPrimary"/>
    <size android:height="0.5dp"/>
</shape>

一个非常简单的解决方案是使用RecyclerView-FlexibleDivider

添加依赖关系:

compile 'com.yqritc:recyclerview-flexibledivider:1.4.0'

添加到你的recyclerview:

recyclerView.addItemDecoration(new HorizontalDividerItemDecoration.Builder(context).build());

这样就完成了!

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。

这很简单，你不需要这么复杂的代码:

DividerItemDecoration divider = new DividerItemDecoration(
    mRVMovieReview.getContext(), DividerItemDecoration.VERTICAL
);
divider.setDrawable(
    ContextCompat.getDrawable(getBaseContext(), R.drawable.line_divider)
);

mRVMovieReview.addItemDecoration(divider);

将它添加到你的drawable: line_divide .xml中

<?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>

对于GridLayoutManager，我使用这个:

public class GridSpacesItemDecoration : RecyclerView.ItemDecoration
{
    private int space;

    public GridSpacesItemDecoration(int space) {
        this.space = space;
    }

    public override void GetItemOffsets(Android.Graphics.Rect outRect, View view, RecyclerView parent, RecyclerView.State state)
    {
        var position = parent.GetChildLayoutPosition(view);

        /// Only for GridLayoutManager Layouts
        var manager = parent.GetLayoutManager() as GridLayoutManager;

        if (parent.GetChildLayoutPosition(view) < manager.SpanCount)
            outRect.Top = space;

        if (position % 2 != 0) {
            outRect.Right = space;
        }

        outRect.Left = space;
        outRect.Bottom = space;
    }
}

这适用于任何跨度。