Msg 消息类
public class Msg { public static final int TYPE_RECEIVED=0; public static final int TYPE_SENT=1; private String content;//消息内容 private int type; public Msg(String content,int type){ this.content=content; this.type=type; } public String getContent(){ return content; } public int getType(){ return type; } }
MsgAdapter
public class MsgAdapter extends RecyclerView.Adapter<MsgAdapter.ViewHoler> { private List<Msg> mMsgList; static class ViewHoler extends RecyclerView.ViewHolder{ LinearLayout leftLayout; LinearLayout rightLayout; TextView leftMsg; TextView rightMsg; public ViewHoler(View view){ super(view); leftLayout = (LinearLayout) view.findViewById(R.id.left_layout); rightLayout = (LinearLayout) view.findViewById(R.id.right_layout); leftMsg = (TextView) view.findViewById(R.id.left_msg); rightMsg = (TextView) view.findViewById(R.id.right_msg); } } public MsgAdapter(List<Msg> msgList){ mMsgList = msgList; } @Override public ViewHoler onCreateViewHolder(ViewGroup parent, int viewType) { View view = LayoutInflater.from(parent.getContext()).inflate (R.layout.msg_item,parent,false); return new ViewHoler(view); } @Override public void onBindViewHolder(ViewHoler holder, int position) { Msg msg = mMsgList.get(position); if (msg.getType()==Msg.TYPE_RECEIVED){ holder.leftLayout.setVisibility(View.VISIBLE);//显示 holder.rightLayout.setVisibility(View.GONE);//隐藏 holder.leftMsg.setText(msg.getContent()); }else if (msg.getType()==Msg.TYPE_SENT){ holder.rightLayout.setVisibility(View.VISIBLE); holder.leftLayout.setVisibility(View.GONE); holder.rightMsg.setText(msg.getContent()); } } @Override public int getItemCount() { return mMsgList.size(); } }
MainActivity
public class MainActivity extends AppCompatActivity { private List<Msg> msgList =new ArrayList<>(); private EditText inputText; private Button send; private RecyclerView msgRecyclerView; private MsgAdapter adapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initMsgs(); inputText = (EditText) findViewById(R.id.input_text); send = (Button) findViewById(R.id.send); msgRecyclerView = (RecyclerView) findViewById(R.id.msg_recycler_view); LinearLayoutManager layoutManager = new LinearLayoutManager(this); msgRecyclerView.setLayoutManager(layoutManager); adapter= new MsgAdapter(msgList); msgRecyclerView.setAdapter(adapter); send.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { String content = inputText.getText().toString(); if(!"".equals(content)){ Msg msg = new Msg(content, Msg.TYPE_SENT); msgList.add(msg); adapter.notifyItemInserted(msgList.size() - 1);//更新消息 msgRecyclerView.scrollToPosition(msgList.size() - 1);//定位到消息中最后一行 inputText.setText("");//清空 } } }); } private void initMsgs() { Msg msg1= new Msg("你好呀",Msg.TYPE_RECEIVED); msgList.add(msg1); Msg msg2 = new Msg("你好,你是谁呐",Msg.TYPE_SENT); msgList.add(msg2); Msg msg3= new Msg("我是小明同学,很高兴认识你~",Msg.TYPE_RECEIVED); msgList.add(msg3); } }
msg_item.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="wrap_content" android:padding="5dp"> <LinearLayout android:id="@+id/left_layout" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="left" android:background="@drawable/message_left"> <TextView android:id="@+id/left_msg" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" android:layout_margin="4dp" android:textColor="#fff"/> </LinearLayout> <LinearLayout android:id="@+id/right_layout" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="right" android:background="@drawable/message_right"> <TextView android:id="@+id/right_msg" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" android:layout_margin="2dp" android:textColor="#fff"/> </LinearLayout> </LinearLayout>
activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" android:background="#d8e0e8"> <android.support.v7.widget.RecyclerView android:id="@+id/msg_recycler_view" android:layout_height="0dp" android:layout_width="match_parent" android:layout_weight="1"/> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content"> <EditText android:id="@+id/input_text" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:hint="请输入" android:maxLines="2"/> <Button android:id="@+id/send" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="发送"/> </LinearLayout> </LinearLayout>