Android 在同一ListAdapter中显示不同的对象

Android 在同一ListAdapter中显示不同的对象,android,listadapter,Android,Listadapter,我想在同一个列表视图中显示不同类型的对象,但我不知道如何通过getItem(position) 列表视图显示消息的列表,这些消息可以是聊天,也可以是通知,并且聊天和通知项具有不同的布局 这是适配器: public class MailboxAdapter extends BaseAdapter { private ArrayList<Messages> m_alMessages = null; private Messages getItem(int positi

我想在同一个
列表视图中显示不同类型的对象,但我不知道如何通过
getItem(position)

列表视图
显示
消息的列表
,这些消息可以是
聊天
,也可以是
通知
,并且
聊天
通知
项具有不同的布局

这是适配器:

public class MailboxAdapter extends BaseAdapter {

    private ArrayList<Messages> m_alMessages = null;

    private Messages getItem(int position) {

        return m_alMessages.get(position)
    }

   @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        if (m_alMessages != null) {
            if (getItem(position).isChat()) {
                final Chat cChatItem = getItem(position);
                if (convertView == null) {
                    //Cat logic
                    // ...
                }
            } else {
                final Notification nNotifItem = getItem(position);

                 if (convertView == null) {
                    //Notification logic
                    // ...
                }

            }
        }
    }
通知
聊天
课程:

public class Notification extends Message { ... }

public class Cat extends Message { ... }
在启动活动时,我正在从web服务检索聊天列表和通知列表,因此我必须将它们以各自的顺序(日期)添加到新的消息列表中,然后使用此
消息列表实例化m adapter


这是一种好的做法吗

只需向类对象添加一个布尔标志,并在适配器中检查该标志,如果是聊天,则使用一种布局,如果标记为通知,则使用另一种布局。没问题

有一个教程实际上或多或少地介绍了如何使用listView中的不同视图布局


在适配器中创建两个视图持有者,一个用于聊天,一个用于通知。然后,在getView()中,获取要为其创建视图的对象,检查布尔标志,实例化正确的支架并根据标志放大视图,然后设置视图元素,如果只有一个类,则ListView将显示您设置该元素的视图。

只需向类对象添加布尔标志,并在适配器中检查标志,如果是聊天,则使用一种布局,如果它被标记为通知,则为另一个。没问题

有一个教程实际上或多或少地介绍了如何使用listView中的不同视图布局


在适配器中创建两个视图持有者,一个用于聊天,一个用于通知。然后,在getView()中,获取要为其创建视图的对象,检查布尔标志,实例化正确的支架,并根据标志对视图进行充气,然后设置视图元素,就像只有一个类一样,ListView将显示您设置该元素的视图。

正如o0rebelious0o所说,在对象中使用标志或id。然后,在适配器中使用和来区分项目类型。因此,在getView中,您将只收到兼容的convertView。

正如o0rebelious0o所说,在对象中使用标志或id。然后,在适配器中使用和来区分项目类型。因此,在getView中,您将只收到兼容的convertView。

我已经这样做了

我有一个单一的列表,其中有3种不同类型的对象列表(如旅游/酒店/签证)

三种不同类型的对象列表每个列表包含一种不同类型的对象,但是有一个我用于标识的扭曲我有三种类型的对象列表,所以我将Map>传递给适配器,检查下面的示例

        BookingDetails details = gson.fromJson(result, BookingDetails.class);
        Map<String, List<Object>> serviceListMap = new HashMap<>();
        if (details.getHotelList() != null) {
            List<Object> list = new ArrayList<>();
            list.addAll(details.getHotelList());
            serviceListMap.put("Hotel", list);
        }
        if (details.getTourList() != null) {
            List<Object> list = new ArrayList<>();
            list.addAll(details.getTourList());
            serviceListMap.put("Tour", list);
        }
        if (details.getVisaList() != null) {
            List<Object> list = new ArrayList<>();
            list.addAll(details.getVisaList());
            serviceListMap.put("Visa", list);
        }
        if (serviceListMap.size() > 0){
            HomeListAdapter adapter = new HomeListAdapter(HomeActivity.this, serviceListMap);
            listView.setAdapter(adapter);
        }
BookingDetails=gson.fromJson(结果,BookingDetails.class);
Map serviceListMap=newhashmap();
if(details.getHotelList()!=null){
列表=新的ArrayList();
list.addAll(details.getHotelList());
serviceListMap.put(“酒店”,列表);
}
if(details.getTourList()!=null){
列表=新的ArrayList();
addAll(details.getTourList());
serviceListMap.put(“Tour”,list);
}
if(details.getVisaList()!=null){
列表=新的ArrayList();
list.addAll(details.getVisaList());
serviceListMap.put(“Visa”,列表);
}
如果(serviceListMap.size()>0){
HomeListAdapter=新的HomeListAdapter(HomeActivity.this,serviceListMap);
setAdapter(适配器);
}
在HomeListAdapter中

public class HomeListAdapter extends BaseAdapter {

private List<String> mDataList;
private Map<String, List<Object>> detailMap;
private Context mContext;

public HomeListAdapter(Context context, Map<String, List<Object>> dataList) {
    mContext = context;
    mDataList = new ArrayList<>(dataList.keySet());
    detailMap = dataList;
}


@Override
public int getCount() {
    return mDataList.size();
}

@Override
public String getItem(int position) {
    return mDataList.get(position);
}

@Override
public long getItemId(int position) {
    return 0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    String key = mDataList.get(position);
    final HolderVoucher holderVoucher;
    if (convertView == null) {
        convertView = View.inflate(mContext, R.layout.item_row, null);
        holderVoucher = new HolderVoucher();
        convertView.setTag(holderVoucher);
        holderVoucher.title = convertView.findViewById(R.id.title);
        holderVoucher.checkin = convertView.findViewById(R.id.checkin);
        holderVoucher.checkout = convertView.findViewById(R.id.checkout);
    } else {
        holderVoucher = (HolderVoucher) convertView.getTag();
    }
    StringBuilder desc = null;
    holderVoucher.title.setText(key);
    List<Object> services = detailMap.get(key);
    desc = new StringBuilder();

    if (services.size() > 0) {
        for (int i = 0; i < services.size(); i++) {
            desc.append("\n");
            if (services.size() > 1) {
                desc.append((i + 1) + ". ");
            }
            if (key.equalsIgnoreCase("Visa")) {
             VisaDetails detail = (VisaDetails) services.get(i);
                desc.append(detail.getVisaName());
                desc.append("\nTravel Date : " +  detail.getTravelDate()));
            } else if (key.equalsIgnoreCase("Hotel")) {
                HotelDetails detail = (HotelDetails) services.get(i);
                desc.append(detail.getHotelName() + "\n" + detail.getRoomType());
                desc.append("\nCheck in : " + detail.getCheckInDate()) +
                        " Check out : " + detail.getCheckOutDate()));
            } else if (key.equalsIgnoreCase("Tour")) {
                TourDetails detail = (TourDetails) services.get(i);
                desc.append("Tour - " + detail.getTourName());
                desc.append("\nTravel Date : " +detail.getTravelDate()));
            }
    holderVoucher.checkin.setText(desc.toString());

    return convertView;
  }
  private class HolderVoucher {
    private TextView title, checkin, checkout;
  }
}
公共类HomeListAdapter扩展了BaseAdapter{
私人名单专家;
私有地图;
私有上下文;
公共HomeListAdapter(上下文、映射数据列表){
mContext=上下文;
mDataList=newarraylist(dataList.keySet());
detailMap=数据列表;
}
@凌驾
public int getCount(){
返回mDataList.size();
}
@凌驾
公共字符串getItem(int位置){
返回mDataList.get(位置);
}
@凌驾
公共长getItemId(int位置){
返回0;
}
@凌驾
公共视图getView(int位置、视图转换视图、视图组父视图){
String key=mDataList.get(位置);
最终持票人持票人持票人;
if(convertView==null){
convertView=查看。充气(mContext,R.layout.item_行,空);
holderVoucher=新的holderVoucher();
convertView.setTag(holderVoucher);
holderVoucher.title=convertView.findViewById(R.id.title);
holderVoucher.checkin=convertView.findViewById(R.id.checkin);
holderVoucher.checkout=convertView.findViewById(R.id.checkout);
}否则{
holderVoucher=(holderVoucher)convertView.getTag();
}
StringBuilder desc=null;
holderVoucher.title.setText(键);
List services=detailMap.get(key);
desc=新的StringBuilder();
if(services.size()>0){
对于(int i=0;i1){
desc.append((i+1)+”);
}
if(关键同等信号情况(“Visa”)){
VisaDetails detail=(VisaDetails)services.get(i);
desc.append(detail.getVisaName());
desc.append(“\n行程日期:+detail.getTravelDate());
}其他条件(钥匙等信号(“酒店”)){
HotelDetails detail=(HotelDetails)services.get(i);
desc.append(detail.getHotelName()+“\n”+detail.getRoomType());
desc.append(“\n签入:
public class HomeListAdapter extends BaseAdapter {

private List<String> mDataList;
private Map<String, List<Object>> detailMap;
private Context mContext;

public HomeListAdapter(Context context, Map<String, List<Object>> dataList) {
    mContext = context;
    mDataList = new ArrayList<>(dataList.keySet());
    detailMap = dataList;
}


@Override
public int getCount() {
    return mDataList.size();
}

@Override
public String getItem(int position) {
    return mDataList.get(position);
}

@Override
public long getItemId(int position) {
    return 0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    String key = mDataList.get(position);
    final HolderVoucher holderVoucher;
    if (convertView == null) {
        convertView = View.inflate(mContext, R.layout.item_row, null);
        holderVoucher = new HolderVoucher();
        convertView.setTag(holderVoucher);
        holderVoucher.title = convertView.findViewById(R.id.title);
        holderVoucher.checkin = convertView.findViewById(R.id.checkin);
        holderVoucher.checkout = convertView.findViewById(R.id.checkout);
    } else {
        holderVoucher = (HolderVoucher) convertView.getTag();
    }
    StringBuilder desc = null;
    holderVoucher.title.setText(key);
    List<Object> services = detailMap.get(key);
    desc = new StringBuilder();

    if (services.size() > 0) {
        for (int i = 0; i < services.size(); i++) {
            desc.append("\n");
            if (services.size() > 1) {
                desc.append((i + 1) + ". ");
            }
            if (key.equalsIgnoreCase("Visa")) {
             VisaDetails detail = (VisaDetails) services.get(i);
                desc.append(detail.getVisaName());
                desc.append("\nTravel Date : " +  detail.getTravelDate()));
            } else if (key.equalsIgnoreCase("Hotel")) {
                HotelDetails detail = (HotelDetails) services.get(i);
                desc.append(detail.getHotelName() + "\n" + detail.getRoomType());
                desc.append("\nCheck in : " + detail.getCheckInDate()) +
                        " Check out : " + detail.getCheckOutDate()));
            } else if (key.equalsIgnoreCase("Tour")) {
                TourDetails detail = (TourDetails) services.get(i);
                desc.append("Tour - " + detail.getTourName());
                desc.append("\nTravel Date : " +detail.getTravelDate()));
            }
    holderVoucher.checkin.setText(desc.toString());

    return convertView;
  }
  private class HolderVoucher {
    private TextView title, checkin, checkout;
  }
}