QQl聊天消息

Activity：

package com.zzw.qqchat;

import java.util.ArrayList;
import java.util.HashMap;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;

public class MainActivity extends Activity {
    private final int VIEW_TYPE = 0x001;
    private final int MESSAGE = 0x002;

    private final int VIEW_TYPE_LEFT = -1;
    private final int VIEW_TYPE_RIGHT = -2;

    private ArrayList<HashMap<Integer, Object>> items;
    private MyAdapter adapter;

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

        final ListView listView = (ListView) findViewById(R.id.list);

        items = new ArrayList<HashMap<Integer, Object>>();

        addData();

        adapter = new MyAdapter(this, -1);
        listView.setAdapter(adapter);

        final EditText et = (EditText) findViewById(R.id.msgEditText);

        findViewById(R.id.msgSend).setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                String msg = et.getText() + "";

                HashMap<Integer, Object> map = new HashMap<Integer, Object>();
                map.put(VIEW_TYPE, VIEW_TYPE_RIGHT);
                map.put(MESSAGE, msg);
                items.add(map);
                // item数据变化时通知adapter刷新及时改变view
                adapter.notifyDataSetChanged();
                // 刷新后清空输入框
                et.setText("");
                // 输入框发送消息后将ListView滚动到底部
                listView.setSelection(ListView.FOCUS_DOWN);

            }
        });
    }

    private void addData() {
        for (int i = 0; i < 10; i++) {
            if (i % 2 == 0) {
                HashMap<Integer, Object> map = new HashMap<Integer, Object>();
                map.put(VIEW_TYPE, VIEW_TYPE_LEFT);
                map.put(MESSAGE, "对方说的消息:" + i);
                items.add(map);
            } else {
                HashMap<Integer, Object> map = new HashMap<Integer, Object>();
                map.put(VIEW_TYPE, VIEW_TYPE_RIGHT);
                map.put(MESSAGE, "我说的消息:" + i);
                items.add(map);
            }
        }
    }

    private class MyAdapter extends ArrayAdapter {
        private LayoutInflater inflater;

        public MyAdapter(Context context, int resource) {
            super(context, resource);
            inflater = LayoutInflater.from(context);
        }

        @Override
        public int getCount() {
            return items.size();
        }

        @Override
        public String getItem(int position) {

            String message = items.get(position).get(MESSAGE) + "";
            return message;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {

            int type = getItemViewType(position);
            String message = getItem(position);

            switch (type) {
            case VIEW_TYPE_LEFT:
                if (convertView == null) {
                    convertView = inflater.inflate(R.layout.left, null);
                }
                TextView textViewLeft = (TextView) convertView.findViewById(R.id.textView);
                textViewLeft.setText(message);
                break;

            case VIEW_TYPE_RIGHT:
                if (convertView == null) {
                    convertView = inflater.inflate(R.layout.right, null);
                }
                TextView textViewRight = (TextView) convertView.findViewById(R.id.textView);
                textViewRight.setText(message);
                break;
            }

            return convertView;
        }

        @Override
        public int getItemViewType(int position) {
            HashMap map = items.get(position);
            int type = (Integer) map.get(VIEW_TYPE);
            return type;
        }

        @Override
        public int getViewTypeCount() {
            return 2;
        }
    }
}

activity_main.xml：

<?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="match_parent" >

    <ListView
        android:id="@+id/list"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_above="@+id/commentLinearLayout"
        android:layout_alignParentTop="true"
        android:divider="@android:color/transparent"
        android:dividerHeight="15dip"
        android:scrollbars="none" />

    <LinearLayout
        android:id="@+id/commentLinearLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:background="#e0e0e0"
        android:orientation="horizontal" >

        <EditText
            android:id="@+id/msgEditText"
            android:layout_width="0dip"
            android:layout_height="wrap_content"
            android:layout_weight="8"
            android:hint="发送消息" />

        <Button
            android:id="@+id/msgSend"
            style="?android:attr/buttonStyleSmall"
            android:layout_width="0dip"
            android:layout_height="wrap_content"
            android:layout_weight="2"
            android:text="发送" />
    </LinearLayout>

</RelativeLayout>

left.xml:

<?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="match_parent"
    android:orientation="horizontal" >

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_centerVertical="true"
        android:singleLine="false"
        android:src="@drawable/ic_launcher" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_toRightOf="@+id/imageView"
        android:background="#ff5252"
        android:text="left" />

</RelativeLayout>

<?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="match_parent"
    android:orientation="horizontal" >

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_centerVertical="true"
        android:src="@drawable/ic_launcher" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_toLeftOf="@+id/imageView"
        android:background="#2196f3"
        android:singleLine="false"
        android:text="right" />

</RelativeLayout>