项目冲刺：聊天界面

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ui.dashboard.DashboardFragment"
    android:orientation="vertical">

    <RelativeLayout
        android:id="@+id/ww"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:background="@drawable/shape_title">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="35dp"
            android:layout_centerInParent="true"
            android:text="讨论"
            android:gravity="center"
            android:textSize="25dp" />

        <!--<Button
            android:id="@+id/edit_up"
            android:layout_width="25dp"
            android:layout_height="25dp"
            android:layout_alignParentLeft="true"
            android:layout_centerVertical="true"
            android:layout_marginLeft="10dp" />-->

    </RelativeLayout>

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/msg_recycle_view"
        android:layout_width="match_parent"
        android:layout_height="529dp"
        android:layout_weight="1"
        android:background="#EEEEEE"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="60dp">

        <EditText
            android:id="@+id/input_text"
            android:gravity="left"
            android:layout_gravity="center"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:hint="  输入聊天内容"
            android:minLines="1"
            android:maxLines="10" />

        <Button
            android:id="@+id/send"
            android:layout_width="wrap_content"
            android:layout_height="40dp"
            android:alpha="0.5"
            android:background="@drawable/btn_shape"
            android:text="发送"
            android:textSize="17dp" />

    </LinearLayout>
</LinearLayout>

　　

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="10dp">
    <LinearLayout
        android:id="@+id/left_layout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="left"
        >

        <TextView
            android:layout_marginTop="10dp"
            android:layout_marginBottom="10dp"
            android:layout_marginLeft="10dp"
            android:layout_marginRight="10dp"
            android:id="@+id/left_msg"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:layout_margin="10dp"
            android:maxWidth="170dp"
            android:background="@drawable/text_shape_2"/>

    </LinearLayout>

    <LinearLayout
        android:id="@+id/right_layout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="right"
        >

        <TextView
            android:layout_marginTop="10dp"
            android:layout_marginBottom="10dp"
            android:layout_marginLeft="10dp"
            android:layout_marginRight="10dp"
            android:id="@+id/right_msg"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:layout_margin="10dp"
            android:maxWidth="170dp"
            android:background="@drawable/text_shape_1"/>

    </LinearLayout>
</LinearLayout>

　　

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

    private List<Msg> mMsgList;

    static class ViewHolder extends RecyclerView.ViewHolder {

        LinearLayout leftLayout;
        LinearLayout rightLayout;
        TextView leftMsg;
        TextView rightMsg;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            leftLayout = itemView.findViewById(R.id.left_layout);
            rightLayout = itemView.findViewById(R.id.right_layout);
            leftMsg = itemView.findViewById(R.id.left_msg);
            rightMsg = itemView.findViewById(R.id.right_msg);
        }
    }

    public MsgAdapter(List<Msg> mMsgList) {
        this.mMsgList = mMsgList;
    }

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

    @Override
    public void onBindViewHolder(@NonNull ViewHolder viewHolder, int i) {
        Msg msg = mMsgList.get(i);

        if (msg.getType() == Msg.TYPE_RECEIVED) {
            viewHolder.leftLayout.setVisibility(View.VISIBLE);
            viewHolder.rightLayout.setVisibility(View.GONE);
            viewHolder.leftMsg.setText(msg.getContent());
        } else {
            viewHolder.leftLayout.setVisibility(View.GONE);
            viewHolder.rightLayout.setVisibility(View.VISIBLE);
            viewHolder.rightMsg.setText(msg.getContent());
        }
    }

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