我正在使用recyclerview，根据添加的日期有一组项目（例如，以A开头的字母表将在标题选项卡A下面，如联系人列表中所示）。问题出现的时候我向下滚动到底部，当我回到顶部时，标题选项卡没有正确分组..就像你拿Eg一样。上面给出..当我向下滚动到底部并且回到顶部时，不是所有以A开头的字母都在头部标签A下面...有些在b头标签下面...项目列表没有问题，它是正确的，只有头部标签。如果有人遇到过这种问题..请帮帮我。谢谢。
这是我在onBindViewHolder（）中的代码
class OrderAdapter extends RecyclerView.Adapter<OrderAdapter.MyViewHolder>
{
private List<OrderPosting> orderPostings;
RecyclerView recyclerView;
int index,size;
String date;
List<String> orderCountInsideAdapter;
List<String> storeCount = new ArrayList<>();
public OrderAdapter(List<OrderPosting> orderPostingList, int size, List<String> orderCount, List<String> storeCount)
{
this.orderPostings = orderPostingList;
this.size = size;
this.orderCountInsideAdapter = orderCount;
this.storeCount = storeCount;
}
public class MyViewHolder extends RecyclerView.ViewHolder
{
TextView name, store, cost, date,statusColor,orderId;
LinearLayout linearLayout,mainLayout;
public MyViewHolder(View view)
{
super(view);
name = (TextView) view.findViewById(R.id.personName);
store = (TextView) view.findViewById(R.id.storeName);
cost = (TextView) view.findViewById(R.id.totalCost);
date = (TextView) view.findViewById(R.id.dateOrdered);
linearLayout = (LinearLayout) view.findViewById(R.id.lastSeenLinearLayout);
mainLayout = (LinearLayout) view.findViewById(R.id.mainLinearLayoutOrderHistory1);
statusColor = (TextView) view.findViewById(R.id.status_color);
orderId = (TextView) view.findViewById(R.id.order_id);
}
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
{
View itemView = LayoutInflater.from(getActivity())
.inflate(R.layout.order_history_items, parent, false);
recyclerView = (RecyclerView) parent;
return new OrderAdapter.MyViewHolder(itemView);
}
@Override
public void onBindViewHolder(final MyViewHolder holder, final int position) {
for (OrderPosting orderPosting: orderPostings)
{
if (Objects.equals(orderCountInsideAdapter.get(position), orderPosting.getOrderId()))
{
DateFormat df = new SimpleDateFormat("yyyy-MM-dd");
String date1 = df.format(new Date());
String dateTime = orderPosting.getDateAdded();
index = dateTime.indexOf(" ");
date = dateTime.substring(0, index);
Log.e("DateChange addes..////", date);
if(Objects.equals(tempDate, date))
{
Log.e("Temp date111/////",tempDate);
}
else
{
Log.e("Temp date222/////",tempDate);
holder.linearLayout.setVisibility(View.VISIBLE);
tempDate = date;
if(Objects.equals(date1, date))
{
holder.date.setText("Today");
}
else
{
SimpleDateFormat readFormat = new SimpleDateFormat("yyyy-mm-dd");
SimpleDateFormat writeFormat = new SimpleDateFormat("dd-mm-yyyy");
try {
convertDate = readFormat.parse(date);
Log.e("Changed date",""+writeFormat.format(convertDate));
} catch (ParseException e) {
e.printStackTrace();
}
holder.date.setText(writeFormat.format(convertDate));
}
}
});
}
@Override
public int getItemCount()
{
return size;
}
}
所以在上面的代码holder.linearLayout.setVisibility（View.VISIBLE）;是头部标签布局..我相应地将其与日期分组。
问题出在if(Objects.equals(tempDate, date))。你的tempDate是一个全局变量，当你在底部时，你保存的日期以Z开头。
通过从底部滚动，最后一个值将首先出现 - >您将设置为假项目。
酷！这是一个分组的适配器。希望能帮助到你：
....如果链接不起作用：
package com.example.kirkegaard.mathirialdesign.Lists;
import android.graphics.Color;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import com.example.kirkegaard.mathirialdesign.R;
import java.util.ArrayList;
import java.util.List;
public class GroupedListActivity extends AppCompatActivity {
private List<CountriesData> countriesData;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_grouped_list);
countriesData = new ArrayList<CountriesData>();
MakeDummyData();
SetupRecyclerView();
}
private void SetupRecyclerView()
{
RecyclerView recyclerView = (RecyclerView)findViewById(R.id.grouped_reyclerview);
GroupedAdapter adapter = new GroupedAdapter(countriesData);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setAdapter(adapter);
}
private void MakeDummyData()
{
MakeDummyDataSection("A", 10);
MakeDummyDataSection("C", 4);
MakeDummyDataSection("G", 13);
MakeDummyDataSection("H", 12);
MakeDummyDataSection("Z", 3);
}
private void MakeDummyDataSection(String letter, int itemsCount)
{
List<String> cities = new ArrayList<String>();
for (int i = 0; i < itemsCount; i++)
{
cities.add(letter + (i+1));
}
countriesData.add(new CountriesData(letter, cities));
}
private class CountriesData
{
public CountriesData(String letter, List<String> countries)
{
Letter = letter;
Countries = countries;
}
public String Letter;
public List<String> Countries;
}
private class GroupedAdapter extends RecyclerView.Adapter
{
private final int HEADER_TYPE = 0;
private final int ITEM_TYPE = 1;
private List<CountriesData> _data;
private List<ItemInformation> _itemTypes;
public GroupedAdapter(List<CountriesData> data)
{
_data = data;
SetItemInformation();
}
private void SetItemInformation()
{
_itemTypes = new ArrayList<ItemInformation>();
int categorySize = _data.size();
for (int i = 0; i < categorySize; i++)
{
_itemTypes.add(new ItemInformation(HEADER_TYPE, i, 0));
for (int j = 0; j < _data.get(i).Countries.size(); j++)
{
_itemTypes.add(new ItemInformation(ITEM_TYPE, i, j));
}
}
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
{
if (viewType == HEADER_TYPE)
{
View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_group_header, parent, false);
return new HeaderViewHolder(itemView);
}
else
{
View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_group_country, parent, false);
return new CountryViewHolder(itemView);
}
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position)
{
ItemInformation info = _itemTypes.get(position);
if (holder instanceof HeaderViewHolder)
{
// Populate header data;
String headerText = _data.get(info.GroupIndex).Letter;
((HeaderViewHolder)holder).PopulateWithData(headerText);
}
else
{
// Populate item data;
String itemText = _data.get(info.GroupIndex).Countries.get(info.InnerIndex);
((CountryViewHolder)holder).PopulateWithData(itemText);
}
}
@Override
public int getItemViewType(int position)
{
ItemInformation info = _itemTypes.get(position);
return info.ItemType;
}
@Override
public int getItemCount()
{
int itemCount = 0;
for (CountriesData countryWithSameLetter: _data)
{
// For header
itemCount ++;
// For content
itemCount += countryWithSameLetter.Countries.size();
}
return itemCount;
}
private class ItemInformation
{
public ItemInformation(int itemType, int groupIndex, int innerIndex)
{
ItemType = itemType;
GroupIndex = groupIndex;
InnerIndex = innerIndex;
}
public int ItemType;
public int GroupIndex;
public int InnerIndex;
}
}
private class HeaderViewHolder extends RecyclerView.ViewHolder
{
private TextView headerTextView;
public HeaderViewHolder(View itemView)
{
super(itemView);
headerTextView = (TextView)itemView.findViewById(R.id.group_header_textview);
}
public void PopulateWithData(String text)
{
headerTextView.setText(text);
}
}
private class CountryViewHolder extends RecyclerView.ViewHolder
{
private TextView itemTextView;
public CountryViewHolder(View itemView)
{
super(itemView);
itemTextView = (TextView)itemView.findViewById(R.id.group_country_textview);
}
public void PopulateWithData(String text)
{
itemTextView.setText(text);
}
}
}