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?
Here is a simple hack to add a divider
Just add a background to the layout of your recycler item as follows
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@drawable/shape_border"
android:gravity="center"
android:orientation="horizontal"
android:padding="5dp">
<ImageView
android:id="@+id/imageViewContactLogo"
android:layout_width="60dp"
android:layout_height="60dp"
android:layout_marginRight="10dp"
android:src="@drawable/ic_user" />
<LinearLayout
android:id="@+id/linearLayout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="0.92"
android:gravity="center|start"
android:orientation="vertical">
<TextView
android:id="@+id/textViewContactName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:singleLine="true"
android:text="Large Text"
android:textAppearance="?android:attr/textAppearanceLarge" />
<TextView
android:id="@+id/textViewStatusOrNumber"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:singleLine="true"
android:text=""
android:textAppearance="?android:attr/textAppearanceMedium" />
</LinearLayout>
<TextView
android:id="@+id/textViewUnreadCount"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginRight="10dp"
android:padding="5dp"
android:text=""
android:textAppearance="?android:attr/textAppearanceMedium"
android:textColor="@color/red"
android:textSize="22sp" />
<Button
android:id="@+id/buttonInvite"
android:layout_width="54dp"
android:layout_height="wrap_content"
android:background="@drawable/ic_add_friend" />
</LinearLayout>
在drawable文件夹中创建以下shape_border.xml文件:
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<gradient
android:angle="270"
android:centerColor="@android:color/transparent"
android:centerX="0.01"
android:startColor="#000" />
</shape>
这是最终的结果-一个带分隔符的RecyclerView。
而不是创建一个形状xml来改变分隔线的高度和颜色，你可以通过编程来创建它:
val divider = DividerItemDecoration(
context,
DividerItemDecoration.VERTICAL)
divider.setDrawable(ShapeDrawable().apply {
intrinsicHeight = resources.getDimensionPixelOffset(R.dimen.dp_15)
paint.color = Color.RED // Note:
// Currently (support version 28.0.0), we
// can not use tranparent color here. If
// we use transparent, we still see a
// small divider line. So if we want
// to display transparent space, we
// can set color = background color
// or we can create a custom ItemDecoration
// instead of DividerItemDecoration.
})
recycler_devices.addItemDecoration(divider)
下面是我在Kotlin中如何做的，在项目之间设置一个默认大小为10dp的简单空间:
class SimpleItemDecoration(context: Context, space: Int = 10) : RecyclerView.ItemDecoration() {
private val spaceInDp = ConvertUtil.dpToPx(context, space)
override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State) {
outRect.left = spaceInDp
outRect.right = spaceInDp
outRect.bottom = spaceInDp
// Add top margin only for the first item to avoid double space between items
if (parent.getChildAdapterPosition(view) == 0) {
outRect.top = spaceInDp
}
}
}
这是dpToPx方法:
fun dpToPx(context: Context, dp: Int): Int {
return (dp * context.resources.displayMetrics.density).toInt()
}
然后像这样将它添加到RecyclerView中:(感谢@MSpeed)
recyclerView.addItemDecoration(SimpleItemDecoration(context))
•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)
