android模拟聊天界面recyclerview实现

来源：互联网发布：我是皇弓箭进阶数据编辑：程序博客网时间：2024/05/22 05:59

这里写图片描述

package com.itheima74.chatui;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.support.v7.widget.LinearLayoutManager;import android.support.v7.widget.RecyclerView;import android.view.View;import android.widget.Button;import android.widget.EditText;import java.util.ArrayList;/** * 聊天界面,使用recyclerview实现 * 效果不好,发送的消息不能靠右对齐, * 不知何故,怎么弄都弄不好,请教! * 问题的解决:用Relativelayout代替linearlayout可以解决上述问题 */public class MainActivity extends AppCompatActivity {    private RecyclerView recyclerview;    private EditText et_input;    private ArrayList<Msg> mMsgList;    private MsgAdapter mMsgAdapter;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initView();        initData();        initAdapter();    }    private void initAdapter() {        mMsgAdapter = new MsgAdapter(mMsgList);        recyclerview.setAdapter(mMsgAdapter);    }    /**     * 初始化数据源     */    private void initData() {        mMsgList = new ArrayList<>();        mMsgList.add(new Msg("Hello!", Msg.TYPE_RECEIVE));        mMsgList.add(new Msg("Hello! Who is that?", Msg.TYPE_SEND));        mMsgList.add(new Msg("This is Jack,Nice to meet you!", Msg.TYPE_RECEIVE));    }    /**     * 初始化控件     */    private void initView() {        recyclerview = (RecyclerView) findViewById(R.id.recyclerview);        et_input = (EditText) findViewById(R.id.et_input);        Button bt_send = (Button) findViewById(R.id.bt_send);        LinearLayoutManager layoutManager = new LinearLayoutManager(this);        layoutManager.setOrientation(LinearLayoutManager.VERTICAL);        recyclerview.setLayoutManager(layoutManager);        bt_send.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                String content = et_input.getText().toString().trim();                // 如果用户没有输入,则是一个空串""                if (!content.isEmpty()) {                    mMsgList.add(new Msg(content, Msg.TYPE_SEND));                    // 通知数据适配器刷新界面                    mMsgAdapter.notifyDataSetChanged();                    // 定位到最后一行                    recyclerview.scrollToPosition(mMsgList.size() - 1);                    // 输入框置空                    et_input.setText("");                }            }        });    }}

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:background="#d8e0e8"    android:orientation="vertical">    <android.support.v7.widget.RecyclerView        android:id="@+id/recyclerview"        android:layout_width="match_parent"        android:layout_height="0dp"        android:layout_weight="1" />    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:orientation="horizontal">        <EditText            android:id="@+id/et_input"            android:layout_width="0dp"            android:layout_height="wrap_content"            android:layout_weight="1"            android:hint="请输入要发送的内容" />        <Button            android:id="@+id/bt_send"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="发送" />    </LinearLayout></LinearLayout>

package com.itheima74.chatui;/** * Created by My on 2017/3/3. */class Msg {    static final int TYPE_RECEIVE = 1;    static final int TYPE_SEND = 2;    String content;    int type;    Msg(String content, int type) {        this.content = content;        this.type = type;    }}

package com.itheima74.chatui;import android.support.v7.widget.RecyclerView;import android.view.View;import android.view.ViewGroup;import android.widget.TextView;import java.util.ArrayList;/** * Created by My on 2017/3/3. */class MsgAdapter extends RecyclerView.Adapter<MsgAdapter.ViewHolder> {    private ArrayList<Msg> mMsgList;    MsgAdapter(ArrayList<Msg> mMsgList) {        this.mMsgList = mMsgList;    }    @Override    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        View view = View.inflate(parent.getContext(), R.layout.recyclerview_item, null);        return new ViewHolder(view);    }    @Override    public void onBindViewHolder(ViewHolder holder, int position) {        Msg msg = mMsgList.get(position);        if (msg.type == Msg.TYPE_RECEIVE) {            holder.tv_receive.setVisibility(View.VISIBLE);            holder.tv_send.setVisibility(View.GONE);            holder.tv_receive.setText(msg.content);        } else {            holder.tv_send.setVisibility(View.VISIBLE);            holder.tv_receive.setVisibility(View.GONE);            holder.tv_send.setText(msg.content);        }    }    @Override    public int getItemCount() {        return mMsgList.size();    }    static class ViewHolder extends RecyclerView.ViewHolder {        private TextView tv_receive;        private TextView tv_send;        ViewHolder(View itemView) {            super(itemView);            tv_receive = (TextView) itemView.findViewById(R.id.tv_receive);            tv_send = (TextView) itemView.findViewById(R.id.tv_send);        }    }}

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:padding="10dp">    <TextView        android:id="@+id/tv_receive"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:background="@drawable/message_left"        android:gravity="center"        android:text="who?"        android:textSize="20sp" />    <TextView        android:id="@+id/tv_send"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentRight="true"        android:layout_below="@id/tv_receive"        android:background="@drawable/message_right"        android:gravity="center"        android:text="i am your father"        android:textSize="20sp" /></RelativeLayout>

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