Android之简单模仿微信聊天界面

先上效果图：

代码如下:

MainActivity.java

package com.example.chatdemo;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.SimpleAdapter;

import java.util.*;

public class MainActivity extends Activity {

    private ListView listView = null;

    private List list = new ArrayList();

    private Button sendBtn = null;

    private EditText input = null;

    private MsgAdapter msgAdapter = null;

    private LinearLayout mainLayout = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);
        initMsgs();

        listView = (ListView) findViewById(R.id.list_view);

        msgAdapter = new MsgAdapter(MainActivity.this, R.layout.msg_item, list);

        sendBtn = (Button) findViewById(R.id.btn_send);

        input = (EditText) findViewById(R.id.edit_send);

        listView.setAdapter(msgAdapter);

        sendBtn.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                String content = input.getText().toString();
                if (!"".equals(content)) {
                    Msg msg = new Msg(content, Msg.TYPE_SEND);
                    list.add(msg);
                    msgAdapter.notifyDataSetChanged(); // 刷新界面
                    listView.setSelection(list.size()); // 把发送的信息定位到最后一行
                    input.setText(""); // 发送框置空
                }
            }
        });

    }

    private void initMsgs() {
        Msg msg1 = new Msg("很高兴见到你，我叫Mike", Msg.TYPE_RECE);
        list.add(msg1);
        Msg msg2 = new Msg("哦？ 你好， 我叫Nicy", Msg.TYPE_SEND);
        list.add(msg2);
        Msg msg3 = new Msg("哈哈，请多指教！ ", Msg.TYPE_RECE);
        list.add(msg3);
    }

}

MsgAdapter.java

package com.example.chatdemo;

import java.util.List;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.LinearLayout;
import android.widget.TextView;

public class MsgAdapter extends ArrayAdapter {

    private int resourceId;

    public MsgAdapter(Context context, int resource, List objects) {
        super(context, resource, objects);
        resourceId = resource;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        Msg msg = getItem(position);
        View view = null;
        ViewHolder viewHolder = null;
        if (convertView == null) {
            view = LayoutInflater.from(getContext()).inflate(resourceId, null);
            viewHolder = new ViewHolder();
            viewHolder.leftLayout = (LinearLayout) view
                    .findViewById(R.id.msg_left);
            viewHolder.rightLayout = (LinearLayout) view
                    .findViewById(R.id.msg_right);
            viewHolder.leftTextView = (TextView) view
                    .findViewById(R.id.left_tv);
            viewHolder.rightTextView = (TextView) view
                    .findViewById(R.id.right_tv);
            view.setTag(viewHolder);
        } else {
            view = convertView;
            viewHolder = (ViewHolder) view.getTag();
        }

        if (msg.getType() == Msg.TYPE_RECE) {   //如果是接收信息
            viewHolder.leftLayout.setVisibility(View.VISIBLE);
            viewHolder.rightLayout.setVisibility(View.GONE);
            viewHolder.leftTextView.setText(msg.getContent());
        } else {  // 如果是发送信息
            viewHolder.leftLayout.setVisibility(View.GONE);
            viewHolder.rightLayout.setVisibility(View.VISIBLE);
            viewHolder.rightTextView.setText(msg.getContent());
        }
        return view;
    }

    private class ViewHolder {

        LinearLayout leftLayout;
        LinearLayout rightLayout;

        TextView leftTextView;
        TextView rightTextView;

    }

}

Msg.java

package com.example.chatdemo;

public class Msg {

    public static final int TYPE_RECE = 0;
    public static final int TYPE_SEND = 1;

    private String content;

    private int type;

    public Msg(String content, int type) {
        super();
        this.content = content;
        this.type = type;
    }

    public String getContent() {
        return content;
    }

    public int getType() {
        return type;
    }

}

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ListView
        android:id="@+id/list_view"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:scrollbars="none"
        android:divider="#ffffff" >
    </ListView>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >

        <EditText
            android:id="@+id/edit_send"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:hint="请输入"
            android:maxLines="1" />

        <Button
            android:id="@+id/btn_send"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="发送" />
    </LinearLayout>

</LinearLayout>

msg_item.xml

<?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:paddingTop="10dp"
    android:orientation="vertical" >

    <LinearLayout
        android:id="@+id/msg_left"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

        <ImageView
            android:id="@+id/left_img"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:background="@drawable/q" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="40dp"
            android:background="@drawable/message_left" >

            <TextView
                android:id="@+id/left_tv"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_gravity="center"
                android:layout_weight="1"
                android:textColor="#fff"
                android:textSize="13sp" />
        </LinearLayout>
    </LinearLayout>

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

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="40dp"
            android:background="@drawable/message_right" >

            <TextView
                android:id="@+id/right_tv"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="center"
                android:textColor="#000"
                android:textSize="13sp" />
        </LinearLayout>

        <ImageView
            android:id="@+id/right_img"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="right"
            android:background="@drawable/w" />
    </LinearLayout>

</LinearLayout>