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>"
...
/>
•PrimeAdapter
通过使用PrimeAdapter,在RecyclerViews中处理分隔符可以非常简单。它为创建和管理分隔器提供了多种功能和更大的灵活性。
您可以按以下方式创建适配器(请参阅GitHub中关于使用的完整文档):
val adapter = PrimeAdapter.with(recyclerView)
.setLayoutManager(LinearLayoutManager(activity))
.set()
.build(ActorAdapter::class.java)
创建适配器实例后,您可以简单地使用以下命令添加分隔符:
//----- Default divider:
adapter.setDivider()
//----- Divider with a custom drawable:
adapter.setDivider(ContextCompat.getDrawable(context, R.drawable.divider))
//----- Divider with a custom color:
adapter.setDivider(Color.RED)
//----- Divider with a custom color and a custom inset:
adapter.setDivider(Color.RED, insetLeft = 16, insetRight = 16)
//----- Deactivate dividers:
adapter.setDivider(null)
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>
使用RecyclerView itemdecoration -一个基本的分隔符样本在Kotlin android
一个完整的示例,包括一个构建器,添加边缘或使用资源颜色的可能性
class SeparatorDecoration constructor(ctx: Context, @ColorRes dividerColor: Int, heightDp: Float) :
RecyclerView.ItemDecoration() {
private val mPaints = Paint()
init {
mPaints.color = dividerColor
val thickness = TypedValue.applyDimension(
TypedValue.COMPLEX_UNIT_DIP,
heightDp,
ctx.resources.displayMetrics
)
mPaints.strokeWidth = thickness
}
override fun getItemOffsets(
outRect: Rect,
view: View,
parent: RecyclerView,
state: RecyclerView.State
) {
val params = view.layoutParams as RecyclerView.LayoutParams
// and add a separator to any view but the last one
val p = params.viewAdapterPosition
// and add a separator to any view but the last one
if (p < state.itemCount) outRect[0, 0, 0] =
mPaints.strokeWidth.toInt() // left, top, right, bottom
else outRect.setEmpty() // 0, 0, 0, 0
}
override fun onDraw(c: Canvas, parent: RecyclerView, state: RecyclerView.State) {
// we set the stroke width before, so as to correctly draw the line we have to offset by width / 2
val offset = (mPaints.strokeWidth / 2).roundToInt()
// this will iterate over every visible view
for (i in 0 until parent.childCount) {
// get the view
val view: View = parent.getChildAt(i)
val params = view.layoutParams as RecyclerView.LayoutParams
// get the position
val position = params.viewAdapterPosition
// and finally draw the separator
if (position < state.itemCount) {
c.drawLine(
view.left.toFloat(),
(view.bottom + offset).toFloat(),
view.right.toFloat(), (view.bottom + offset).toFloat(), mPaints
)
}
}
}
}
设置很简单。只需将您的装饰与其余的初始设置一起添加到您的recyclerView。
val decoration = SeparatorDecoration(context, R.color.primaryColor, 1.5f)
recyclerview.addItemDecoration(decoration)