这是之前在ListView类中使用divider和dividerHeight参数实现的一个例子:

<ListView
    android:id="@+id/activity_home_list_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:divider="@android:color/transparent"
    android:dividerHeight="8dp"/>

然而,在RecyclerView类中我没有看到这样的可能性。

<android.support.v7.widget.RecyclerView
    android:id="@+id/activity_home_recycler_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:scrollbars="vertical"/>

在这种情况下,是否可以定义边距和/或直接添加自定义分隔符视图到列表项的布局中,或者是否有更好的方法来实现我的目标?


当前回答

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。

其他回答

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!

由于没有正确的方法来实现这一点,但正确使用材质设计,我只是做了以下技巧,直接在列表项上添加一个分隔符:

<View
    android:layout_width="match_parent"
    android:layout_height="1dp"
    android:background="@color/dividerColor"/>

使用这个类在你的RecyclerView中设置分隔符。

public class GridSpacingItemDecoration extends RecyclerView.ItemDecoration {

    private int spanCount;
    private int spacing;
    private boolean includeEdge;

    public GridSpacingItemDecoration(int spanCount, int spacing, boolean includeEdge) {
        this.spanCount = spanCount;
        this.spacing = spacing;
        this.includeEdge = includeEdge;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        int position = parent.getChildAdapterPosition(view); // Item position
        int column = position % spanCount; // Item column

        if (includeEdge) {
            outRect.left = spacing - column * spacing / spanCount; // spacing - column * ((1f / spanCount) * spacing)
            outRect.right = (column + 1) * spacing / spanCount; // (column + 1) * ((1f / spanCount) * spacing)

            if (position < spanCount) { // Top edge
                outRect.top = spacing;
            }
            outRect.bottom = spacing; // Item bottom
        } else {
            outRect.left = column * spacing / spanCount; // column * ((1f / spanCount) * spacing)
            outRect.right = spacing - (column + 1) * spacing / spanCount; // spacing - (column + 1) * ((1f / spanCount) * spacing)
            if (position >= spanCount) {
                outRect.top = spacing; // Item top
            }
        }
    }
}

这实际上并不能解决问题,但是作为一种临时的解决方法,您可以在XML布局中的卡片上设置useCompatPadding属性,使其与在前lollipop版本中测量的相同。

card_view:cardUseCompatPadding="true"
public class VerticalItemDecoration extends RecyclerView.ItemDecoration {

    private boolean verticalOrientation = true;
    private int space = 10;

    public VerticalItemDecoration(int value, boolean verticalOrientation) {
        this.space = value;
        this.verticalOrientation = verticalOrientation;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent,
                               RecyclerView.State state) {
        // Skip first item in the list
        if (parent.getChildAdapterPosition(view) != 0) {
            if (verticalOrientation) {
                outRect.set(space, 0, 0, 0);
            } else if (!verticalOrientation) {
                outRect.set(0, space, 0, 0);
            }
        }
    }
}

mCompletedShippingRecyclerView.addItemDecoration(new VerticalItemDecoration(20,false));