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?
•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)
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。
如果有人想为spaceBetween, paddingLeft, paddingTop, paddingRight和paddingBottom设置不同的值。
class ItemPaddingDecoration(
private val spaceBetween: Int,
private val paddingLeft: Int = spaceBetween,
private val paddingTop: Int = spaceBetween,
private val paddingRight: Int = spaceBetween,
private val paddingBottom: Int = spaceBetween
) : RecyclerView.ItemDecoration() {
override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State) {
val position = parent.getChildAdapterPosition(view)
val orientation = when (val layoutManager = parent.layoutManager) {
is LinearLayoutManager -> {
layoutManager.orientation
}
is GridLayoutManager -> {
layoutManager.orientation
}
else -> {
RecyclerView.HORIZONTAL
}
}
if (orientation == RecyclerView.HORIZONTAL) {
when {
position == 0 -> {
outRect.set(paddingLeft, paddingTop, spaceBetween, paddingBottom)
}
position < parent.adapter!!.itemCount - 1 -> {
outRect.set(0, paddingTop, spaceBetween, paddingBottom)
}
else -> {
outRect.set(0, paddingTop, paddingRight, paddingBottom)
}
}
} else {
when {
position == 0 -> {
outRect.set(paddingLeft, paddingTop, paddingRight, paddingBottom)
}
position < parent.adapter!!.itemCount - 1 -> {
outRect.set(paddingLeft, 0, paddingRight, spaceBetween)
}
else -> {
outRect.set(paddingLeft, 0, paddingRight, paddingBottom)
}
}
}
}
}
实现它自己的RecyclerView版本。ItemDecoration
public class SpacingItemDecoration extends RecyclerView.ItemDecoration {
private int spacingPx;
private boolean addStartSpacing;
private boolean addEndSpacing;
public SpacingItemDecoration(int spacingPx) {
this(spacingPx, false, false);
}
public SpacingItemDecoration(int spacingPx, boolean addStartSpacing, boolean addEndSpacing) {
this.spacingPx = spacingPx;
this.addStartSpacing = addStartSpacing;
this.addEndSpacing = addEndSpacing;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
super.getItemOffsets(outRect, view, parent, state);
if (spacingPx <= 0) {
return;
}
if (addStartSpacing && parent.getChildLayoutPosition(view) < 1 || parent.getChildLayoutPosition(view) >= 1) {
if (getOrientation(parent) == LinearLayoutManager.VERTICAL) {
outRect.top = spacingPx;
} else {
outRect.left = spacingPx;
}
}
if (addEndSpacing && parent.getChildAdapterPosition(view) == getTotalItemCount(parent) - 1) {
if (getOrientation(parent) == LinearLayoutManager.VERTICAL) {
outRect.bottom = spacingPx;
} else {
outRect.right = spacingPx;
}
}
}
private int getTotalItemCount(RecyclerView parent) {
return parent.getAdapter().getItemCount();
}
private int getOrientation(RecyclerView parent) {
if (parent.getLayoutManager() instanceof LinearLayoutManager) {
return ((LinearLayoutManager) parent.getLayoutManager()).getOrientation();
} else {
throw new IllegalStateException("SpacingItemDecoration can only be used with a LinearLayoutManager.");
}
}
}
请注意一下Alex Fu在GitHub上的这个文件:
链接
它是“直接从支持演示中提取”的diveritemdecoration .java示例文件。
在我的项目中导入这个文件后，我能够很好地获得分隔线，并将其作为项目装饰添加到回收器视图。
下面是我的onCreateView在我的片段中包含Recyclerview的样子:
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_recycler_view, container, false);
mRecyclerView = (RecyclerView) rootView.findViewById(R.id.my_recycler_view);
mRecyclerView.addItemDecoration(new DividerItemDecoration(getActivity(), DividerItemDecoration.VERTICAL));
mRecyclerView.setHasFixedSize(true);
mLayoutManager = new LinearLayoutManager(getActivity());
mRecyclerView.setLayoutManager(mLayoutManager);
mRecyclerView.setItemAnimator(new DefaultItemAnimator());
return rootView;
}
我确信可以做额外的造型，但这只是一个起点。：）
