Android 具有两种视图类型的recyclerview不更改视图类型

在我的android firebase聊天应用程序中，我想使用recyclerview根据消息类型（即传入或传出）显示聊天列表

首先让我告诉你firebase的数据结构

<ConversationId>
    <MsgId>
       text :"Hello"
       timestamp :<timestamp>
       sender :<sender's uid>
       receiver :<receiver's uid>

如果上述条件为真，则应为传出消息

---

我运行了上面的代码，但对所有消息没有任何更改，只有传入的消息布局正在应用

您需要使用

viewHolder.getItemViewType（）

内部

onBindViewHolder

试试下面的代码

@Override
public void onBindViewHolder(final RecyclerView.ViewHolder holder, final int listPosition) {

   SingleChatList chat=chatList.get(listPosition);
   switch (holder.getItemViewType()) {
      case 0:
          incoming incommindHolder= (incoming ) holder;
          //TODO Bind data view Holder
          incommindHolder.message.setText(chat.getMsg());
          incommindHolder.time.setText(String.valueOf(chat.getTimestamp()));
          break;

      case 1:
          outgoing outGoindHolder= (outgoing) holder;
          //TODO Bind data view Holder
          outGoindHolder.message.setText(chat.getMsg());
          outGoindHolder.time.setText(String.valueOf(chat.getTimestamp()));
          break;
   }
}

---

注意：请了解java命名约定mate:）

在您的代码中，您对每种情况都使用return。将一个值赋给局部变量，然后在最后返回该值被认为是一种良好的做法。具有多个出口的方法更难调试，也可能更难读取。此外，您在最后将null作为viewholder返回。请尝试此更新的代码并检查是否有效

public class MultiViewTypeAdapter extends RecyclerView.Adapter {

private List<SingleChatList> chatList;
int total_types;

public class incoming extends RecyclerView.ViewHolder {
    public TextView message, time;

    //public CircleImageView dp;
    public incoming(View view) {
        super(view);
        message = (TextView) view.findViewById(R.id.message_text);
        time = (TextView) view.findViewById(R.id.timestamp_text);
    }
}

public class outgoing extends RecyclerView.ViewHolder {
    public TextView message, time;
    //public CircleImageView dp;

    public outgoing(View view) {
        super(view);
        message = (TextView) view.findViewById(R.id.message_text_view);
        time = (TextView) view.findViewById(R.id.timestamp_text_view);
    }
}

public MultiViewTypeAdapter(List<SingleChatList> data) {
    this.chatList = data;
    total_types = chatList.size();
}


@Override
public int getItemViewType(int position) {
    int swi = 0;
    if (chatList.get(position).getSender() == FirebaseAuth.getCurrentUser().getUid()) {
        swi = 1;
    } else {
        swi = 0;
    }
    return swi;
}

@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    RecyclerView.ViewHolder holder = null;
    View view;
    switch (viewType) {
        case 0:
            view = LayoutInflater.from(parent.getContext()).inflate(R.layout.msg_incoming_bubble, parent, false);
            holder = new incoming(view);
            break;
        case 1:
            view = LayoutInflater.from(parent.getContext()).inflate(R.layout.msg_outgoing_bubble, parent, false);
            holder = new outgoing(view);
            break;
    }
    return holder;
}

@Override
public void onBindViewHolder(final RecyclerView.ViewHolder holder, final int listPosition) {

    SingleChatList chat = chatList.get(listPosition);
    switch (holder.getItemViewType()) {
        case 0:
            if (chat != null) {
                ((incoming) holder).message.setText(chat.getMsg());
                ((incoming) holder).time.setText(String.valueOf(chat.getTimestamp()));
            }
            break;
        case 1:
            if (chat != null) {
                ((outgoing) holder).message.setText(chat.getMsg());
                ((incoming) holder).time.setText(String.valueOf(chat.getTimestamp()));
            }
            break;
    }
}

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

公共类MultiViewTypeAdapter扩展了RecyclerView.Adapter{ 私人列表聊天列表； int-total_类型； 公共类传入扩展RecyclerView.ViewHolder{ 公共文本查看消息、时间； //公众圈图像dp； 公共传入（视图）{ 超级（视图）； message=（TextView）view.findViewById（R.id.message\u text）； time=（TextView）view.findViewById（R.id.timestamp\u text）； } } 公共类传出扩展RecyclerView.ViewHolder{ 公共文本查看消息、时间； //公众圈图像dp； 公共传出（视图）{ 超级（视图）； message=（TextView）view.findViewById（R.id.message\u text\u view）； time=（TextView）view.findViewById（R.id.timestamp\u text\u view）； } } 公共多视图类型适配器（列表数据）{ this.chatList=数据； total_types=chatList.size（）； } @凌驾 public int getItemViewType（int位置）{ int-swi=0； if（chatList.get（position.getSender（）==FirebaseAuth.getCurrentUser（）.getUid（））{ swi=1； }否则{ swi=0； } 返回swi； } @凌驾 public RecyclerView.ViewHolder onCreateViewHolder（视图组父级，int-viewType）{ RecyclerView.ViewHolder=null； 视图； 开关（视图类型）{ 案例0： view=LayoutInflater.from（parent.getContext（））.flate（R.layout.msg\u incoming\u bubble，parent，false）； 支架=新引入（视图）； 打破 案例1： view=LayoutInflater.from（parent.getContext（））.flate（R.layout.msg\u outgoing\u bubble，parent，false）； 持有者=新的输出（视图）； 打破 } 报税表持有人； } @凌驾 public void onBindViewHolder（final RecyclerView.ViewHolder holder，final int listPosition）{ SingleChatList chat=chatList.get（listPosition）； 开关（holder.getItemViewType（））{ 案例0： 如果（聊天！=null）{ （（传入）holder.message.setText（chat.getMsg（））； （（传入）holder.time.setText（String.valueOf（chat.getTimestamp（））； } 打破 案例1： 如果（聊天！=null）{ （（传出）holder.message.setText（chat.getMsg（））； （（传入）holder.time.setText（String.valueOf（chat.getTimestamp（））； } 打破 } } @凌驾 public int getItemCount（）{ 返回chatList.size（）； } }

---

onBindViewHolder函数使用holder.getItemViewType（）获取viewtype

@Override
public void onBindViewHolder(final RecyclerView.ViewHolder holder, final int listPosition) {

   SingleChatList chat=chatList.get(listPosition);
   switch (holder.getItemViewType()) {
      case 0:
          incoming incommindHolder= (incoming ) holder;
          //TODO Bind data view Holder
          incommindHolder.message.setText(chat.getMsg());
          incommindHolder.time.setText(String.valueOf(chat.getTimestamp()));
          break;

      case 1:
          outgoing outGoindHolder= (outgoing) holder;
          //TODO Bind data view Holder
          outGoindHolder.message.setText(chat.getMsg());
          outGoindHolder.time.setText(String.valueOf(chat.getTimestamp()));
          break;
   }
}

public class MultiViewTypeAdapter extends RecyclerView.Adapter {

private List<SingleChatList> chatList;
int total_types;

public class incoming extends RecyclerView.ViewHolder {
    public TextView message, time;

    //public CircleImageView dp;
    public incoming(View view) {
        super(view);
        message = (TextView) view.findViewById(R.id.message_text);
        time = (TextView) view.findViewById(R.id.timestamp_text);
    }
}

public class outgoing extends RecyclerView.ViewHolder {
    public TextView message, time;
    //public CircleImageView dp;

    public outgoing(View view) {
        super(view);
        message = (TextView) view.findViewById(R.id.message_text_view);
        time = (TextView) view.findViewById(R.id.timestamp_text_view);
    }
}

public MultiViewTypeAdapter(List<SingleChatList> data) {
    this.chatList = data;
    total_types = chatList.size();
}


@Override
public int getItemViewType(int position) {
    int swi = 0;
    if (chatList.get(position).getSender() == FirebaseAuth.getCurrentUser().getUid()) {
        swi = 1;
    } else {
        swi = 0;
    }
    return swi;
}

@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    RecyclerView.ViewHolder holder = null;
    View view;
    switch (viewType) {
        case 0:
            view = LayoutInflater.from(parent.getContext()).inflate(R.layout.msg_incoming_bubble, parent, false);
            holder = new incoming(view);
            break;
        case 1:
            view = LayoutInflater.from(parent.getContext()).inflate(R.layout.msg_outgoing_bubble, parent, false);
            holder = new outgoing(view);
            break;
    }
    return holder;
}

@Override
public void onBindViewHolder(final RecyclerView.ViewHolder holder, final int listPosition) {

    SingleChatList chat = chatList.get(listPosition);
    switch (holder.getItemViewType()) {
        case 0:
            if (chat != null) {
                ((incoming) holder).message.setText(chat.getMsg());
                ((incoming) holder).time.setText(String.valueOf(chat.getTimestamp()));
            }
            break;
        case 1:
            if (chat != null) {
                ((outgoing) holder).message.setText(chat.getMsg());
                ((incoming) holder).time.setText(String.valueOf(chat.getTimestamp()));
            }
            break;
    }
}

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