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Java 在哪里操作Recyclerview适配器（Android）中的数据

java android

Java 在哪里操作Recyclerview适配器（Android）中的数据,java,android,android-recyclerview,Java,Android,Android Recyclerview,我的日期时间当前存储为UNIX时间戳。我想在我的Recyclerview中将其显示为h:mm a 我应该在哪里将UNIX时间戳转换为RecyclerView适配器/Viewholder中的正常时间（就最佳性能而言） 我应该在RecyclerView.Adapter的getItemViewType（int位置）中执行，还是在ViewHolder类的onBindViewHolder或bind函数中执行 编辑：我的代码 public class ChatListAdapter extends Recy

我的日期时间当前存储为UNIX时间戳。我想在我的Recyclerview中将其显示为h:mm a

我应该在哪里将UNIX时间戳转换为RecyclerView适配器/Viewholder中的正常时间（就最佳性能而言）

我应该在
RecyclerView.Adapter
的
getItemViewType（int位置）
中执行，还是在
ViewHolder
类的
onBindViewHolder
或
bind
函数中执行

编辑：我的代码

public class ChatListAdapter extends RecyclerView.Adapter {


    private final LayoutInflater mInflater;
    private List<Chat> mChats;
    private final String ownerMe = "OWNER_ME";
    private static final int VIEW_TYPE_MESSAGE_ME = 1;
    private static final int VIEW_TYPE_MESSAGE_ME_CORNER = 2;
    private static final int VIEW_TYPE_MESSAGE_BF = 3;
    private static final int VIEW_TYPE_MESSAGE_BF_CORNER = 4;

    ChatListAdapter(Context context) {mInflater = LayoutInflater.from(context);}

    @Override
    public int getItemViewType(int position) {
        Chat chat = mChats.get(position);

        if(chat.getUser().equals(ownerMe)) {
            if(position == mChats.size()-1) {
                return VIEW_TYPE_MESSAGE_ME_CORNER;
            }
            if(chat.getUser().equals(mChats.get(position+1).getUser())) {
                return VIEW_TYPE_MESSAGE_ME;
            } else {
                return VIEW_TYPE_MESSAGE_ME_CORNER;
            }
        } else {
            if(position == mChats.size()-1) {
                return VIEW_TYPE_MESSAGE_BF_CORNER;
            }
            if(chat.getUser().equals(mChats.get(position+1).getUser())) {
                return VIEW_TYPE_MESSAGE_BF;
            } else {
                return VIEW_TYPE_MESSAGE_BF_CORNER;
            }
        }
    }

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

        if(viewType == VIEW_TYPE_MESSAGE_ME || viewType == VIEW_TYPE_MESSAGE_ME_CORNER) {
            view = mInflater.inflate(R.layout.recyclerview_item_right, parent, false);
            return new MeMessageHolder(view);
        } else if (viewType == VIEW_TYPE_MESSAGE_BF || viewType == VIEW_TYPE_MESSAGE_BF_CORNER) {
            view = mInflater.inflate(R.layout.recyclerview_item_left, parent, false);
            return new BfMessageHolder(view);
        }
        return null;

    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        if (mChats != null) {
            Chat current = mChats.get(position);
            long unixTime= current.getUnixTime();
            Date time = new java.util.Date(unixTime*1000L);
            SimpleDateFormat sdf = new java.text.SimpleDateFormat("h:mm a");
            String formattedTime = sdf.format(time);

            switch (holder.getItemViewType()) {
                case VIEW_TYPE_MESSAGE_ME:
                    ((MeMessageHolder) holder).bind(current, formattedTime, false);
                    break;
                case VIEW_TYPE_MESSAGE_ME_CORNER:
                    ((MeMessageHolder) holder).bind(current, formattedTime, true);
                    break;
                case VIEW_TYPE_MESSAGE_BF:
                    ((BfMessageHolder) holder).bind(current, formattedTime, false);
                    break;
                case VIEW_TYPE_MESSAGE_BF_CORNER:
                    ((BfMessageHolder) holder).bind(current, formattedTime, true);
                    break;
            }
        }
    }

    class MeMessageHolder extends RecyclerView.ViewHolder {
        private final TextView chatItemView;
        private final ImageView cornerRightIImageView;
        private final ConstraintLayout constraintLayout;
        private final TextView timeItemView;


        private MeMessageHolder(View itemView) {
            super(itemView);
            chatItemView = itemView.findViewById(R.id.textView);
            cornerRightIImageView = itemView.findViewById(R.id.corner_view_right);
            constraintLayout = itemView.findViewById(R.id.chat_bubble_id);
            timeItemView = itemView.findViewById(R.id.text_message_time);

        }

        void bind(Chat chat, String formattedTime, boolean isCorner) {
            chatItemView.setText(chat.getMessage());
            timeItemView.setText(formattedTime);
            if(isCorner) {
                constraintLayout.setBackgroundResource(R.drawable.chat_bubble_v2);
            } else {
                cornerRightIImageView.setVisibility(View.INVISIBLE);
            }
        }
    }

    class BfMessageHolder extends RecyclerView.ViewHolder {
        private final TextView chatItemView;
        private final ImageView cornerLeftImageView;
        private final ConstraintLayout constraintLayout;
        private final TextView timeItemView;

        private BfMessageHolder(View itemView) {
            super(itemView);
            chatItemView = itemView.findViewById(R.id.textView);
            cornerLeftImageView = itemView.findViewById(R.id.corner_view_left);
            constraintLayout = itemView.findViewById(R.id.chat_bubble_id);
            timeItemView = itemView.findViewById(R.id.text_message_time);
        }

        void bind(Chat chat, String formattedTime, boolean isCorner) {
            chatItemView.setText(chat.getMessage());
            timeItemView.setText(formattedTime);
            if(isCorner) {
                constraintLayout.setBackgroundResource(R.drawable.chat_bubble_v3);
            } else {
                cornerLeftImageView.setVisibility(View.INVISIBLE);
            }
        }
    }

    void setChats(List<Chat> chats) {
        mChats = chats;
        notifyDataSetChanged();
    }

    @Override
    public int getItemCount() {
        if(mChats!=null)
            return mChats.size();
        else return 0;
    }
}

公共类ChatListAdapter扩展了RecyclerView.Adapter{
私人最终布局平面图；
私人名单mChats；
私有最终字符串ownerMe=“OWNER\u ME”；
私有静态最终整型视图\类型\消息\ ME=1；
私有静态最终整数视图\类型\消息\我\角=2；
私有静态最终整型视图\类型\消息\ BF=3；
私有静态最终int视图\类型\消息\ BF\角=4；
ChatListAdapter（上下文）{mInflater=LayoutInflater.from（上下文）；}
@凌驾
public int getItemViewType（int位置）{
Chat Chat=mChats.get（位置）；
if（chat.getUser（）.equals（ownerMe））{
if（position==mChats.size（）-1）{
返回视图\类型\消息\我\角落；
}
if（chat.getUser（）.equals（mChats.get（position+1.getUser（）））{
返回视图\类型\消息\我；
}否则{
返回视图\类型\消息\我\角落；
}
}否则{
if（position==mChats.size（）-1）{
返回视图\类型\消息\窗口\角落；
}
if（chat.getUser（）.equals（mChats.get（position+1.getUser（）））{
返回视图\u类型\u消息\u BF；
}否则{
返回视图\类型\消息\窗口\角落；
}
}
}
@凌驾
public RecyclerView.ViewHolder onCreateViewHolder（视图组父级，int-viewType）{
视图；
if（viewType==视图\类型\消息\我| \视图类型==视图\类型\消息\我|角）{
视图=最小充气器。充气（R.layout.recyclerview\u item\u right，parent，false）；
返回新的MeMessageHolder（视图）；
}else if（viewType==视图\类型\消息\ BF \视图类型==视图\类型\消息\ BF \角）{
视图=最小充气器。充气（R.layout.recyclerview\u item\u left，父项，false）；
返回新的BfMessageHolder（视图）；
}
返回null；
}
@凌驾
BindViewHolder上的公共无效（RecyclerView.ViewHolder，int位置）{
if（mChats！=null）{
聊天当前=mChats.get（位置）；
long unixTime=current.getUnixTime（）；
Date time=new java.util.Date（unixTime*1000L）；
SimpleDataFormat sdf=新java.text.SimpleDataFormat（“h:mm a”）；
字符串formattedTime=sdf.format（时间）；
开关（holder.getItemViewType（））{
案例视图\类型\消息\我：
（（MeMessageHolder）holder）.bind（当前，格式化时间，false）；
打破
案例视图\类型\消息\我\角落：
（（MeMessageHolder）holder）.bind（当前，格式化时间，true）；
打破
案例视图\u类型\u消息\u BF：
（（BfMessageHolder）holder）.bind（当前，格式化时间，false）；
打破
案例视图\u类型\u消息\u BF\u角落：
（（BfMessageHolder）holder）.bind（当前，格式化时间，true）；
打破
}
}
}
类MeMessageHolder扩展了RecyclerView.ViewHolder{
私有最终文本视图chatItemView；
私有最终图像视图cornerRightIImageView；
私有最终约束约束约束约束约束约束约束；
私有最终文本视图时间项视图；
私有MeMessageHolder（视图项视图）{
超级（项目视图）；
chatItemView=itemView.findViewById（R.id.textView）；
cornerRightIImageView=itemView.findViewById（R.id.corner\u view\u right）；
constraintLayout=itemView.findviewbyd（R.id.chat\u bubble\u id）；
timeItemView=itemView.findViewById（R.id.text\u message\u time）；
}
无效绑定（聊天聊天、字符串格式化时间、布尔值isCorner）{
chatItemView.setText（chat.getMessage（））；
timeItemView.setText（格式化时间）；
if（isCorner）{
constraintLayout.setBackgroundResource（R.drawable.chat\u bubble\u v2）；
}否则{
CornerRightIIImageView.setVisibility（视图.不可见）；
}
}
}
类BfMessageHolder扩展了RecyclerView.ViewHolder{
私有最终文本视图chatItemView；
私有最终图像视图左图像视图；
私有最终约束约束约束约束约束约束约束；
私有最终文本视图时间项视图；
私人BfMessageHolder（查看项目视图）{
超级（项目视图）；
chatItemView=itemView.findViewById（R.id.textView）；
cornerLeftImageView=itemView.findViewById（R.id.corner\u view\u left）；
constraintLayout=itemView.findviewbyd（R.id.chat\u bubble\u id）；
timeItemView=itemView.findViewById（R.id.text\u message\u time）；
}
无效绑定（聊天聊天、字符串格式化时间、布尔值isCorner）{
chatItemView.setText（chat.getMessage（））；
timeItemView.setText（格式化时间）；
if（isCorner）{
constraintLayout.setBackgroundResource（R.drawable.chat\u bubble\u v3）；
}否则{
cornerLeftImageView.setVisibility（视图.不可见）；
}
}
}
无效设置聊天（列表聊天）{
mChats=聊天；
notifyDataSetChanged（）；
}
@凌驾
public int getItemCount（）{
if（mChats！=null）
返回mChats.size（）；
否则返回0；
}
}
这个方法正确吗？我在上的
中格式化了日期

java.util.Date dateTime=new java.util.Date((long)timeStamp*1000);



final long unixTime = 1372339860;
final String formattedDtm = Instant.ofEpochSecond(unixTime)
        .atZone(ZoneId.of("GMT-4"))
        .format(formatter);

System.out.println(formattedDtm);   // => '2013-06-27 09:31:00'



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

  @NonNull
  @Override
  public ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
    View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.sample_view, viewGroup, false);
    return new ViewHolder(view);
  }

  @Override
  public void onBindViewHolder(@NonNull ViewHolder viewHolder, int i) {
    viewHolder.bind(i);
  }

  public class ViewHolder extends RecyclerView.ViewHolder {

    public ViewHolder(@NonNull View itemView) {
      super(itemView);
    }

    void bind(int position) {
      // Do your data updates here.
    }
  }
}



class Chat {

   private Long unixTime;

   // another code

   public Long getUnixTime() {
      return unixTime;
   }

   public String convertedUnixTimeToString(String format) {
      // Also need to add some format validation     
      if(format == null) {
         // do some action, like trowing exception, or setting default value in format
      } 

      Date time = new java.util.Date(unixTime*1000L);
      SimpleDateFormat sdf = new java.text.SimpleDateFormat(format);

      return sdf.format(time);
   }

}




public class ChatListAdapter extends RecyclerView.Adapter {


    private final LayoutInflater mInflater;
    private List<Chat> mChats;
    private final String ownerMe = "OWNER_ME";
    private static final int VIEW_TYPE_MESSAGE_ME = 1;
    private static final int VIEW_TYPE_MESSAGE_ME_CORNER = 2;
    private static final int VIEW_TYPE_MESSAGE_BF = 3;
    private static final int VIEW_TYPE_MESSAGE_BF_CORNER = 4;

    ChatListAdapter(Context context) {mInflater = LayoutInflater.from(context);}

    @Override
    public int getItemViewType(int position) {
        Chat chat = mChats.get(position);

        if(chat.getUser().equals(ownerMe)) {
            if(position == mChats.size()-1) {
                return VIEW_TYPE_MESSAGE_ME_CORNER;
            }
            if(chat.getUser().equals(mChats.get(position+1).getUser())) {
                return VIEW_TYPE_MESSAGE_ME;
            } else {
                return VIEW_TYPE_MESSAGE_ME_CORNER;
            }
        } else {
            if(position == mChats.size()-1) {
                return VIEW_TYPE_MESSAGE_BF_CORNER;
            }
            if(chat.getUser().equals(mChats.get(position+1).getUser())) {
                return VIEW_TYPE_MESSAGE_BF;
            } else {
                return VIEW_TYPE_MESSAGE_BF_CORNER;
            }
        }
    }

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

        if(viewType == VIEW_TYPE_MESSAGE_ME || viewType == VIEW_TYPE_MESSAGE_ME_CORNER) {
            view = mInflater.inflate(R.layout.recyclerview_item_right, parent, false);
            return new MeMessageHolder(view);
        } else if (viewType == VIEW_TYPE_MESSAGE_BF || viewType == VIEW_TYPE_MESSAGE_BF_CORNER) {
            view = mInflater.inflate(R.layout.recyclerview_item_left, parent, false);
            return new BfMessageHolder(view);
        }
        return null;

    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        if (mChats != null) {
            Chat current = mChats.get(position);

            switch (holder.getItemViewType()) {
                case VIEW_TYPE_MESSAGE_ME:
                    ((MeMessageHolder) holder).bind(current, false);
                    break;
                case VIEW_TYPE_MESSAGE_ME_CORNER:
                    ((MeMessageHolder) holder).bind(current, true);
                    break;
                case VIEW_TYPE_MESSAGE_BF:
                    ((BfMessageHolder) holder).bind(current, false);
                    break;
                case VIEW_TYPE_MESSAGE_BF_CORNER:
                    ((BfMessageHolder) holder).bind(current, true);
                    break;
            }
        }
    }

    class MeMessageHolder extends RecyclerView.ViewHolder {
        private final TextView chatItemView;
        private final ImageView cornerRightIImageView;
        private final ConstraintLayout constraintLayout;
        private final TextView timeItemView;


        private MeMessageHolder(View itemView) {
            super(itemView);
            chatItemView = itemView.findViewById(R.id.textView);
            cornerRightIImageView = itemView.findViewById(R.id.corner_view_right);
            constraintLayout = itemView.findViewById(R.id.chat_bubble_id);
            timeItemView = itemView.findViewById(R.id.text_message_time);

        }

        void bind(Chat chat, boolean isCorner) {
            chatItemView.setText(chat.getMessage());
            timeItemView.setText(chat.convertedUnixTimeToString("h:mm a"));
            if(isCorner) {
                constraintLayout.setBackgroundResource(R.drawable.chat_bubble_v2);
            } else {
                cornerRightIImageView.setVisibility(View.INVISIBLE);
            }
        }
    }

    class BfMessageHolder extends RecyclerView.ViewHolder {
        private final TextView chatItemView;
        private final ImageView cornerLeftImageView;
        private final ConstraintLayout constraintLayout;
        private final TextView timeItemView;

        private BfMessageHolder(View itemView) {
            super(itemView);
            chatItemView = itemView.findViewById(R.id.textView);
            cornerLeftImageView = itemView.findViewById(R.id.corner_view_left);
            constraintLayout = itemView.findViewById(R.id.chat_bubble_id);
            timeItemView = itemView.findViewById(R.id.text_message_time);
        }

        void bind(Chat chat, boolean isCorner) {
            chatItemView.setText(chat.getMessage());
            timeItemView.setText(chat.convertedUnixTimeToString("h:mm a"));
            if(isCorner) {
                constraintLayout.setBackgroundResource(R.drawable.chat_bubble_v3);
            } else {
                cornerLeftImageView.setVisibility(View.INVISIBLE);
            }
        }
    }

    void setChats(List<Chat> chats) {
        mChats = chats;
        notifyDataSetChanged();
    }

    @Override
    public int getItemCount() {
        if(mChats!=null)
            return mChats.size();
        else return 0;
    }
}