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如何为多个与不在同一个回收视图列表中的所选视窗匹配的视窗创建一个回收视图适配器

android-viewholder recycler-adapter android-recyclerview android

Eyal Israel · 技术社区 · 6 年前

我想知道如何创建一个可容纳多个视图持有者的回收器视图适配器,每次用该适配器实例化回收器视图时,我只想看到一个特定类型,而不是混合类型。

我在Android活动中有两个不同的屏幕,每个屏幕都显示项目/卡片的列表。一个是文本和数字,另一个是照片。现在,我为每个对象都有两个不同的自定义适配器,我想要实现的是一个适配器的灵活性,它可以根据屏幕显示的对象类型在不同类型的对象之间延迟,并且只列出我需要的行。

我所看到的所有例子都是混合类型的对象,这不是我所追求的。

适配器代码附加在下面。

    public class MultiAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    private ArrayList<MYDataProvider> arrayList;
    private final static int VIEW0 = 0;
    private final static int VIEW1 = 1;

    public MultiAdapter(ArrayList<MyDataProvider> _arrayList) {
        this.arrayList = new ArrayList<>();
        this.arrayList = _arrayList;
    }

    @Override
    public int getItemViewType(int position) {
        switch (position) {
            case 0:
                return VIEW0;

            case 1:
            default:
                return VIEW1;
        }//switch
    }//get item view type

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
        int layoutRes;
        View view;
        RecyclerView.ViewHolder viewholder;

        switch (viewType) {
            case VIEW0:
                layoutRes = R.layout.card_item;
                view = LayoutInflater.from(viewGroup.getContext()).inflate(layoutRes, viewGroup, false);
                viewholder =  new E1(view);
                break;

            case VIEW1:
            default:
                layoutRes = R.layout.item_layout;
                view = LayoutInflater.from(viewGroup.getContext()).inflate(layoutRes, viewGroup, false);
                viewholder =  new E2(view);
                break;
        }//switch

        return viewholder;
    }//on create

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        switch (holder.getItemViewType()) {
            case VIEW0: {
                MyDataProvider mydata = arrayList.get(position);
                ((E1)holder).name1.setText(mydata.getD_name() + "this is item " + position);
                ((E1)holder).imageView1.setImageResource(arrayList.get(position).getImg_res());
            }
            break;

            case VIEW1: {
                MyDataProvider mydata = arrayList.get(position);
                ((E2)holder).name2.setText(mydata.getD_name() + "this is item " + position);
                ((E2)holder).imageView2.setImageResource(arrayList.get(position).getImg_res());
            }
            break;
        }//switch
    }//on bind


    @Override
    public int getItemCount() {
        return arrayList.size();
    }

    public class E1 extends mainViewHolder {
        ImageView imageView1;
        TextView name1;

        public E1(View itemView) {
            super(itemView);
            imageView1 = itemView.findViewById(R.id.image);
            name1 = itemView.findViewById(R.id.d_name);
        }
    }//e1 class

        public class E2 extends mainViewHolder {
        ImageView imageView2;
        TextView name2;

        public E2(View itemView) {
            super(itemView);
            imageView2 = itemView.findViewById(R.id.person_photo);
            name2 = itemView.findViewById(R.id.person_name);
        }
    }//e2 class

    public class mainViewHolder extends RecyclerView.ViewHolder {
        public mainViewHolder(@NonNull View itemView) {
            super(itemView);
        }
    }
}//adapter

2 回复 | 直到 6 年前

MarcinR 6 年前

getItemViewType(int position)

enum TYPE {
    VIEW0,
    VIEW1
}

private TYPE itemType;

public Test(ArrayList<MyDataProvider> _arrayList, TYPE itemType) {
    this.arrayList = new ArrayList<>();
    this.arrayList = _arrayList;
    this.itemType = itemType;
}

itemType onCreateViewHolder

@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

LayoutInflater inflater = LayoutInflater.from(parent.getContext());
switch (itemType) {
    case VIEW0:
        return new NotificationsAdapter.ReferralTriggerViewHolder(inflater.inflate(R.layout.row_referral_trigger, parent, false));
    case VIEW1:
        return new NotificationsAdapter.UserNotificationViewHolder(inflater.inflate(R.layout.row_layout_user_notification, parent, false));
    default:
        return new NotificationsAdapter.UserNotificationViewHolder(inflater.inflate(R.layout.row_layout_user_notification, parent, false));
}

}

Shivam Kumar mnp343 6 年前

public class NotificationsAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

    private static final int VIEW_TYPE_REFERRAL_TRIGGER = 1;
    private static final int VIEW_TYPE_NOTIFICATION = 2;
    private static final int VIEW_TYPE_PROMOTION = 3;

    private List<Object> notificationObjectsList;
    private Activity mActivity;

    public NotificationsAdapter(Activity activity, List<Object> mNotificationList) {
        mActivity = activity;
        notificationObjectsList = new ArrayList<>(mNotificationList);
    }


    // Used to avoid the duplicate items recycling
    @Override
    public long getItemId(int position) {
        return position;
    }

    // Used to avoid the duplicate items recycling
    @Override
    public int getItemViewType(int position) {

        if ((notificationObjectsList.get(position) != null) && (notificationObjectsList.get(position) instanceof ReferralData)) {
            return VIEW_TYPE_REFERRAL_TRIGGER;
        } else if (notificationObjectsList.get(position) instanceof Promotion) {
            return VIEW_TYPE_PROMOTION;
        } else {
            return VIEW_TYPE_NOTIFICATION;
        }

    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        LayoutInflater inflater = LayoutInflater.from(parent.getContext());
        switch (viewType) {
            case VIEW_TYPE_REFERRAL_TRIGGER:
                return new NotificationsAdapter.ReferralTriggerViewHolder(inflater.inflate(R.layout.row_referral_trigger, parent, false));
            case VIEW_TYPE_NOTIFICATION:
                return new NotificationsAdapter.UserNotificationViewHolder(inflater.inflate(R.layout.row_layout_user_notification, parent, false));
            case VIEW_TYPE_PROMOTION:
                return new NotificationsAdapter.PromotionViewHolder(inflater.inflate(R.layout.row_layout_app_promotions, parent, false));
            default:
                return new NotificationsAdapter.UserNotificationViewHolder(inflater.inflate(R.layout.row_layout_user_notification, parent, false));
        }

    }

    @Override
    public void onBindViewHolder(final RecyclerView.ViewHolder viewHolder, final int position) {

        if (viewHolder instanceof PromotionViewHolder) {
            final PromotionViewHolder promotionViewHolder = (PromotionViewHolder) viewHolder;
            //populate data of promotion view holder

        } else if (viewHolder instanceof UserNotificationViewHolder) {
            final UserNotificationViewHolder notificationViewHolder = (UserNotificationViewHolder) viewHolder;
            //populate data of UserNotificationViewHolder view holder

        } else if (viewHolder instanceof ReferralTriggerViewHolder) {
            final ReferralTriggerViewHolder referralTriggerViewHolder = (ReferralTriggerViewHolder) viewHolder;
            //populate data of ReferralTriggerViewHolder view holder
        }
    }

    @Override
    public int getItemCount() {
        return notificationObjectsList.size();
    }


    private class UserNotificationViewHolder extends RecyclerView.ViewHolder {

        private UserNotificationViewHolder(View itemView) {
            super(itemView);

        }


    }

    private class PromotionViewHolder extends RecyclerView.ViewHolder  {

        private PromotionViewHolder(View itemView) {
            super(itemView);
        }


    }

    private class ReferralTriggerViewHolder extends RecyclerView.ViewHolder {
        ReferralTriggerView referralTriggerView;

        private ReferralTriggerViewHolder(View itemView) {
            super(itemView);
            referralTriggerView = itemView.findViewById(R.id.rtv_notification_adapter);
        }
    }

}