子项可见性的 RecyclerView 问题

Question

大家好，我正在创建类似 whatsapp 的聊天应用程序，但在 RecyclerView 中面临 Childs Visibilties 问题，它包含我的消息和来自服务器的消息我已经在单一布局中为我的消息和服务器消息定义了这两个项目，我'm 根据布尔值设置可见性；但项目没有正确呈现

适配器 Class :

public class MessageDetailsListAdapter extends RecyclerView.Adapter<MessageDetailsListAdapter.MessageViewHolder> {

private List<MessageModel> messagesList;
private Activity activityContext;
public MessageDetailsListAdapter(List<MessageModel> messagesList,Activity activityContext) {
    this.messagesList = messagesList;
    this.activityContext = activityContext;
}


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

@Override
public void onBindViewHolder(MessageViewHolder messageViewHolder, final int i) {
    final MessageModel msg = messagesList.get(i);
    if(msg.getIsMessageSentbyMe())
    {
        messageViewHolder.card_linear.setVisibility(View.GONE);
        messageViewHolder.messageTextMe.setText(msg.getMsgText());
        messageViewHolder.userNameMe.setText(msg.getSenderName());
        messageViewHolder.timeStampMe.setText(msg.getSentTime());
        messageViewHolder.card_linearMe.setOnLongClickListener(new OnLongClickListener() {

            @Override
            public boolean onLongClick(View v) {
                // TODO Auto-generated method stub
                Intent intent = new Intent(activityContext.getString(R.string.brMessageDetailsDeleteItem));
                intent.putExtra("deletePosition", i);
                activityContext.sendBroadcast(intent);
                return false;
            }
        });
    }
    else
    {
        messageViewHolder.card_linearMe.setVisibility(View.GONE);
        messageViewHolder.messageText.setText(msg.getMsgText());
        messageViewHolder.userName.setText(msg.getSenderName());
        messageViewHolder.timeStamp.setText(msg.getSentTime());
        messageViewHolder.card_linear.setOnLongClickListener(new OnLongClickListener() {

            @Override
            public boolean onLongClick(View v) {
                // TODO Auto-generated method stub
                Intent intent = new Intent(activityContext.getString(R.string.brMessageDetailsDeleteItem));
                intent.putExtra("deletePosition", i);
                activityContext.sendBroadcast(intent);
                return false;
            }
        });
    }
}

@Override
public MessageViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        View itemView = LayoutInflater.from(viewGroup.getContext())
                .inflate(R.layout.messagedetail_listitem, viewGroup,false);


        return new MessageDetailsListAdapter.MessageViewHolder(itemView);
}

public static class MessageViewHolder extends RecyclerView.ViewHolder {



    public LinearLayout card_linear,card_linearMe;
    public TextView userName,messageText,timeStamp,userNameMe,messageTextMe,timeStampMe;
    public MessageViewHolder(View v) {
        super(v);
        card_linear = (LinearLayout) v.findViewById(R.id.card_linear);
        card_linearMe = (LinearLayout) v.findViewById(R.id.card_linearMe);
        userName = (TextView) v.findViewById(R.id.userName);
        messageText = (TextView) v.findViewById(R.id.messageText);
        timeStamp = (TextView) v.findViewById(R.id.timeStamp);
        userNameMe = (TextView) v.findViewById(R.id.userNameMe);
        messageTextMe = (TextView) v.findViewById(R.id.messageTextMe);
        timeStampMe = (TextView) v.findViewById(R.id.timeStampMe);
    }
}

public void add(MessageModel messageModel) {
    // TODO Auto-generated method stub
    messagesList.add(messageModel);
    notifyItemInserted(messagesList.size());
}

    public void addAll(Collection<MessageModel> messages)
    {
   messagesList.clear();
   messagesList.addAll(messagesList);
   notifyDataSetChanged();
     }
public void remove(MessageModel mDelete) {
    // TODO Auto-generated method stub
    messagesList.remove(mDelete);
    notifyDataSetChanged();
}
  }

messagedetail_listitem.xml :

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:paddingTop="@dimen/message_detail_padding_top" >

<LinearLayout
    android:id="@+id/card_linear"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="@dimen/card_liner_margin_left"
    android:layout_marginRight="@dimen/card_liner_margin_right"
    android:background="@drawable/message_holder_white"
    android:orientation="vertical"
    android:padding="@dimen/card_linear_padding" >

    <TextView
        android:id="@+id/userName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Me"
        android:paddingLeft="@dimen/card_linear_padding"
        style="@style/MessageUserNameFont"
         />

    <TextView
        android:id="@+id/messageText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="@dimen/message_text_margin_top"
        android:paddingBottom="@dimen/message_text_padding"
        android:paddingLeft="@dimen/message_text_padding"
        android:paddingTop="@dimen/message_text_padding"
        style="@style/MessageTextFont"
        android:text="hii fdsfdsfsdf sdf dsf sdfs"
         />

    <TextView
        android:id="@+id/timeStamp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="right"
        android:layout_marginRight="@dimen/time_stamp_margin_right"
        android:gravity="right"
        android:text="22:20"
        style="@style/MessageTextFont"
     />
</LinearLayout>
 <LinearLayout
    android:id="@+id/card_linearMe"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="@dimen/card_linearme_margin_left"
    android:layout_marginRight="@dimen/card_linearme_margin_right"
    android:background="@drawable/message_holder_blue"
    android:orientation="vertical"
    android:padding="@dimen/card_linearme_padding" >

    <TextView
        android:id="@+id/userNameMe"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Me"
        android:textColor="@android:color/white" />

    <TextView
        android:id="@+id/messageTextMe"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="@dimen/message_text_margin_top"
        android:paddingBottom="@dimen/message_text_padding"
        android:paddingRight="@dimen/message_text_padding"
        android:paddingTop="@dimen/message_text_padding"
        android:text="hii"
        android:textColor="@android:color/white" />

    <TextView
        android:id="@+id/timeStampMe"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="right"
        android:layout_marginRight="@dimen/time_stamp_margin_right"
        android:gravity="right"
        android:text="22:20"
        android:textColor="@android:color/white" />
</LinearLayout>

Answer 1

这里要理解的重要一点是视图持有者被重用。

首先，你有这个条件：

if(msg.getIsMessageSentbyMe())
{
    messageViewHolder.card_linear.setVisibility(View.GONE);
    ...
}

以后你有：

else
{
    messageViewHolder.card_linearMe.setVisibility(View.GONE);
}

现在想象一下您第一次使用 VH 并且消息是（例如）由您发送的。您已有效隐藏 card_linear。

假设视图持有者现在需要重新用于不是您发送的消息。您还将使 card_linearMe 的可见性消失。

您的 VH 发生的情况是，在发生这种情况后，两种布局都不可见。要修复它，请添加以下行：

if(msg.getIsMessageSentbyMe())
{
    messageViewHolder.card_linear.setVisibility(View.GONE);
    messageViewHolder.card_linearMe.setVisibility(View.VISIBLE);
    ...
}
else 
{
    messageViewHolder.card_linear.setVisibility(View.VISIBLE);
    messageViewHolder.card_linearMe.setVisibility(View.GONE);
}

子项可见性的 RecyclerView 问题

RecyclerView Issue with Child Items Visibilities

android

android-5.0-lollipop

android-recyclerview