我观看了来自此link的教程，该教程创建了可扩展的recyclerview，而没有使用第三方应用程序来扩展recyclerview并在其中填充自定义网格布局。
下面是使用的代码：
MainActivity
public class MainActivity extends AppCompatActivity {
RecyclerView expanderRecyclerView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
expanderRecyclerView = findViewById(R.id.recyclerView);
initiateExpander();
}
private void initiateExpander() {
ArrayList<String> parentList = new ArrayList<>();
ArrayList<ArrayList> childListHolder = new ArrayList<>();
parentList.add("Fruits & Vegetables");
parentList.add("Beverages & Health");
parentList.add("Home & Kitchen");
ArrayList<String> childNameList = new ArrayList<>();
childNameList.add("Apple");
childNameList.add("Mango");
childNameList.add("Banana");
childListHolder.add(childNameList);
childNameList = new ArrayList<>();
childNameList.add("Red bull");
childNameList.add("Maa");
childNameList.add("Horlicks");
childListHolder.add(childNameList);
childNameList = new ArrayList<>();
childNameList.add("Knife");
childNameList.add("Vessels");
childNameList.add("Spoons");
childListHolder.add(childNameList);
ExpandableRecyclerViewAdapter expandableCategoryRecyclerViewAdapter =
new ExpandableRecyclerViewAdapter(getApplicationContext(), parentList,
childListHolder);
expanderRecyclerView.setLayoutManager(new LinearLayoutManager(getApplicationContext()));
expanderRecyclerView.setAdapter(expandableCategoryRecyclerViewAdapter);
}
}
ExpandableRecyclerViewAdapter
public class ExpandableRecyclerViewAdapter extends
RecyclerView.Adapter<ExpandableRecyclerViewAdapter.ViewHolder> {
int previousExpandedPosition = -1, mExpandedPosition=-1;
ArrayList<String> nameList = new ArrayList<String>();
ArrayList<String> image = new ArrayList<String>();
ArrayList<Integer> counter = new ArrayList<Integer>();
ArrayList<ArrayList> itemNameList = new ArrayList<ArrayList>();
boolean isExpanded=true;
Context context;
public ExpandableRecyclerViewAdapter(Context context,
ArrayList<String> nameList,
ArrayList<ArrayList> itemNameList) {
this.nameList = nameList;
this.itemNameList = itemNameList;
this.context = context;
Log.d("namelist", nameList.toString());
for (int i = 0; i < nameList.size(); i++) {
counter.add(0);
}
}
public class ViewHolder extends RecyclerView.ViewHolder {
TextView name;
ImageButton dropBtn;
RecyclerView cardRecyclerView;
CardView cardView;
public ViewHolder(View itemView) {
super(itemView);
name = itemView.findViewById(R.id.categoryTitle);
dropBtn = itemView.findViewById(R.id.categoryExpandBtn);
cardRecyclerView = itemView.findViewById(R.id.innerRecyclerView);
cardView = itemView.findViewById(R.id.cardView);
}
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.card_collapseview, parent, false);
ExpandableRecyclerViewAdapter.ViewHolder vh = new ExpandableRecyclerViewAdapter.ViewHolder(v);
return vh;
}
@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
holder.name.setText(nameList.get(position));
InnerRecyclerViewAdapter itemInnerRecyclerView = new InnerRecyclerViewAdapter(context ,itemNameList.get(position));
holder.cardRecyclerView.setLayoutManager(new GridLayoutManager(context, 2));
holder.cardView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (counter.get(position) % 2 == 0) {
holder.cardRecyclerView.setVisibility(View.VISIBLE);
} else {
holder.cardRecyclerView.setVisibility(View.GONE);
}
counter.set(position, counter.get(position) + 1);
}
});
holder.cardRecyclerView.setAdapter(itemInnerRecyclerView);
}
@Override
public int getItemCount() {
return nameList.size();
}
}
InnerRecyclerViewAdapter
public class InnerRecyclerViewAdapter extends
RecyclerView.Adapter<InnerRecyclerViewAdapter.ViewHolder> {
public ArrayList<String> nameList = new ArrayList<String>();
Context context;
public InnerRecyclerViewAdapter(Context context, ArrayList<String> nameList)
{
this.nameList = nameList;
this.context=context;
}
public class ViewHolder extends RecyclerView.ViewHolder {
TextView name;
CardView cardView;
public ViewHolder(View itemView) {
super(itemView);
name = itemView.findViewById(R.id.itemTextView);
cardView=itemView.findViewById(R.id.cardView);
}
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.card_expand_item_view, parent, false);
InnerRecyclerViewAdapter.ViewHolder vh = new InnerRecyclerViewAdapter.ViewHolder(v);
return vh;
}
@Override
public void onBindViewHolder(ViewHolder holder, final int position) {
holder.name.setText(nameList.get(position));
holder.cardView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Toast.makeText(context, "Clicked on "+nameList.get(position),Toast.LENGTH_LONG).show();
}
});
}
@Override
public int getItemCount() {
return nameList.size();
}
}
我无法弄清楚如何修改此代码，以使recyclerview一次扩展一行...如果已经扩展了另一行，则应在另一行扩展时自动将其关闭行。
请指导我该怎么做。
答案 0 :(得分：1)
所以我自己找到了使用自定义recyclerview进行扩展的gridlayout的答案。
实际上，我按照@ADM的建议删除了recyclerview并使用了ExpandableListView。
还使用gridlayout在子级布局中添加了自定义recyclerview，一次只能打开一个子级。
如果有人需要，我将在下面发布代码...
MainActivity
public class MainActivity extends AppCompatActivity {
private static ExpandableListView expandableListView;
private static ExpandableListAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
expandableListView = (ExpandableListView) findViewById(R.id.simple_expandable_listview);
// Setting group indicator null for custom indicator
expandableListView.setGroupIndicator(null);
setItems();
setListener();
}
// Setting headers and childs to expandable listview
void setItems() {
// Array list for header
ArrayList<String> header = new ArrayList<String>();
// Array list for child items
List<String> child1 = new ArrayList<String>();
List<String> child2 = new ArrayList<String>();
List<String> child3 = new ArrayList<String>();
List<String> child4 = new ArrayList<String>();
// Hash map for both header and child
HashMap<String, List<String>> hashMap = new HashMap<String, List<String>>();
// Adding headers to list
for (int i = 1; i < 5; i++) {
header.add("Group " + i);
}
// Adding child data
for (int i = 1; i < 5; i++) {
child1.add("Group 1 - " + " : Child" + i);
}
// Adding child data
for (int i = 1; i < 5; i++) {
child2.add("Group 2 - " + " : Child" + i);
}
// Adding child data
for (int i = 1; i < 6; i++) {
child3.add("Group 3 - " + " : Child" + i);
}
// Adding child data
for (int i = 1; i < 7; i++) {
child4.add("Group 4 - " + " : Child" + i);
}
// Adding header and childs to hash map
hashMap.put(header.get(0), child1);
hashMap.put(header.get(1), child2);
hashMap.put(header.get(2), child3);
hashMap.put(header.get(3), child4);
adapter = new ExpandableListAdapter(MainActivity.this, header, hashMap);
// Setting adpater over expandablelistview
expandableListView.setAdapter(adapter);
}
// Setting different listeners to expandablelistview
void setListener() {
// This listener will show toast on group click
expandableListView.setOnGroupClickListener(new OnGroupClickListener() {
@Override
public boolean onGroupClick(ExpandableListView listview, View view,
int group_pos, long id) {
Toast.makeText(MainActivity.this,
"You clicked : " + adapter.getGroup(group_pos),
Toast.LENGTH_SHORT).show();
return false;
}
});
// This listener will expand one group at one time
// You can remove this listener for expanding all groups
expandableListView
.setOnGroupExpandListener(new OnGroupExpandListener() {
// Default position
int previousGroup = -1;
@Override
public void onGroupExpand(int groupPosition) {
if (groupPosition != previousGroup)
// Collapse the expanded group
expandableListView.collapseGroup(previousGroup);
previousGroup = groupPosition;
}
});
// This listener will show toast on child click
expandableListView.setOnChildClickListener(new OnChildClickListener() {
@Override
public boolean onChildClick(ExpandableListView listview, View view,
int groupPos, int childPos, long id) {
Toast.makeText(
MainActivity.this,
"You clicked : " + adapter.getChild(groupPos, childPos),
Toast.LENGTH_SHORT).show();
return false;
}
});
}
}
ExpandableListAdapter
//For expandable list view use BaseExpandableListAdapter
public class ExpandableListAdapter extends BaseExpandableListAdapter {
private Context _context;
private List<String> header; // header titles
RecyclerView recyclerView;
// Child data in format of header title, child title
private HashMap<String, List<String>> child;
public ExpandableListAdapter(Context context, List<String> listDataHeader,
HashMap<String, List<String>> listChildData) {
this._context = context;
this.header = listDataHeader;
this.child = listChildData;
}
@Override
public Object getChild(int groupPosition, int childPosititon) {
// This will return the child
return this.child.get(this.header.get(groupPosition)).get(
childPosititon);
}
@Override
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}
@Override
public View getChildView(int groupPosition, final int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
View v=convertView;
if (v == null) {
v = LayoutInflater.from(parent.getContext()).inflate(R.layout.childs, parent,
false);
String groupname=header.get(groupPosition);
recyclerView = (RecyclerView) v.findViewById(R.id.recyclerview);
InnerRecyclerViewAdapter sbc=new InnerRecyclerViewAdapter(_context,
child,groupPosition,groupname);
recyclerView.setLayoutManager(new GridLayoutManager(_context,2));
recyclerView.setAdapter(sbc);
}else
{
v = LayoutInflater.from(parent.getContext()).inflate(R.layout.childs,parent,false);
String groupname=header.get(groupPosition);
recyclerView = (RecyclerView) v.findViewById(R.id.recyclerview);
InnerRecyclerViewAdapter sbc=new InnerRecyclerViewAdapter(_context,
child,groupPosition,groupname);
recyclerView.setLayoutManager(new GridLayoutManager(_context,2));
recyclerView.setAdapter(sbc);
}
return v;
}
@Override
public int getChildrenCount(int groupPosition) {
// return children count
return 1;
}
@Override
public Object getGroup(int groupPosition) {
// Get header position
return this.header.get(groupPosition);
}
@Override
public int getGroupCount() {
// Get header size
return this.header.size();
}
@Override
public long getGroupId(int groupPosition) {
return groupPosition;
}
@Override
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
// Getting header title
String headerTitle = (String) getGroup(groupPosition);
// Inflating header layout and setting text
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) this._context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.header, parent, false);
}
TextView header_text = (TextView) convertView.findViewById(R.id.header);
header_text.setText(headerTitle);
// If group is expanded then change the text into bold and change the
// icon
if (isExpanded) {
header_text.setTypeface(null, Typeface.BOLD);
header_text.setCompoundDrawablesWithIntrinsicBounds(0, 0,
R.drawable.ic_up, 0);
} else {
// If group is not expanded then change the text back into normal
// and change the icon
header_text.setTypeface(null, Typeface.NORMAL);
header_text.setCompoundDrawablesWithIntrinsicBounds(0, 0,
R.drawable.ic_down, 0);
}
return convertView;
}
@Override
public boolean hasStableIds() {
return false;
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;
}
}
InnerRecyclerViewAdapter
public class InnerRecyclerViewAdapter extends RecyclerView.Adapter<InnerRecyclerViewAdapter.ViewHolder> {
private HashMap<String, List<String>> child;
Context context;
int groupPosition;
String groupname;
public InnerRecyclerViewAdapter(Context context, HashMap<String, List<String>> child,int groupPosition,String groupname) {
this.child = child;
this.context=context;
this.groupPosition=groupPosition;
this.groupname=groupname;
}
public class ViewHolder extends RecyclerView.ViewHolder {
TextView name;
CardView cardView;
public ViewHolder(View itemView) {
super(itemView);
name = itemView.findViewById(R.id.itemTextView);
cardView=itemView.findViewById(R.id.cardView);
}
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.card_expand_item_view, parent, false);
InnerRecyclerViewAdapter.ViewHolder vh = new InnerRecyclerViewAdapter.ViewHolder(v);
return vh;
}
@Override
public void onBindViewHolder(ViewHolder holder, final int position) {
final String childText = (String) getChild(groupPosition,position);
holder.name.setText(childText);
holder.cardView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Toast.makeText(context, "Clicked on "+childText, Toast.LENGTH_LONG).show();
}
});
}
@Override
public int getItemCount() {
return child.size();
}
public Object getChild(int groupPosition, int childPosititon) {
// This will return the child
return this.child.get(groupname).get(
childPosititon);
}
}
XML如下：
activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:padding="5dp" >
<ExpandableListView
android:id="@+id/simple_expandable_listview"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:divider="#000000"
android:dividerHeight="1dp" >
</ExpandableListView>
</LinearLayout>
card_expand_item_view.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.CardView
android:id="@+id/cardView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="2dp">
<LinearLayout
android:id="@+id/linearLayoutHolder"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="10dp">
<TextView
android:id="@+id/itemTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginTop="5dp"
android:text="Fresh Fruits"
android:textAlignment="center"
android:textSize="14sp" />
</LinearLayout>
</android.support.v7.widget.CardView>
</RelativeLayout>
childs.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/rv1"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="5dp"
android:scrollbars="vertical"/>
</RelativeLayout>
header.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="5dp" >
<TextView
android:id="@+id/header"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:textColor="#ff00"
android:drawablePadding="10dp"
android:textSize="18sp" />
</LinearLayout>
使用此命令后的输出将类似于this
