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?
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
}
}
}
}
以下是我的偷懒方法,但它很有效:
将CardView包装在一个布局中,并在父布局上设置一个填充/边距来模拟分隔符,并强制将普通分隔符设置为null。
文件list_item.xml
<LinearLayout
android:id="@+id/entry_item_layout_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:paddingBottom="<divider_size>" > // This is the divider
<CardView
android:layout_width="<width_size>"
android:layout_height="<height_size>">
...
</CardView>
</LinearLayout
文件list.xml
<RecyclerView
android:divider="@null"
android:layout_width="<width_size>"
android:layout_height="<height_size>"
...
/>
这是我在Kotlin中为列显示(网格)所做的
class ItemDecorationColumns(private val space: Int) : ItemDecoration() {
override fun getItemOffsets(
outRect: Rect,
view: View,
parent: RecyclerView,
state: RecyclerView.State
) {
val position = parent.getChildLayoutPosition(view)
val manager = parent.layoutManager as GridLayoutManager?
val spanCount = manager?.spanCount ?: 0
if (position < spanCount) {
outRect.top = space
}
if (position % 2 != 0) {
outRect.right = space
}
outRect.left = space
outRect.bottom = space
}
}
使用
rvAlbums.addItemDecoration(ItemDecorationColumns(resources.getDimensionPixelSize(R.dimen.space)))