Android 仿微信QQ聊天界面

一些IM聊天软件的展现形式是左右分开的形式。比如说，别人给你发的信息全部靠左显示，你自己发给别人的信息全部靠右显示。

而我们的ListView很多时候是显示同一个布局，其实BaseAdapter中有2个重要的方法在大多数情况下我们并未使用到，一个是public int getViewTypeCount()，显示ListView中有多少种布局（默认是显示是1），像微信那样聊天界面，是有2种布局方式；另外一个getItemViewType()，可以让不同item条目加载不同的布局,下面就简单的模拟下微信的聊天界面做法：

MainActivity.java

package com.jackie.wechat;

import java.util.ArrayList;

import java.util.List;

import android.app.Activity;

import android.os.Bundle;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.BaseAdapter;

import android.widget.ListView;

import android.widget.TextView;

public class MainActivity extends Activity {

private ListView mListView;

private List<Person> persons;

private int TYPE_COUNT = 2;

private int LEFT = 0;

private int RIGHT = 1;

private LayoutInflater
mInflater;

private MyAdapter adapter;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

mListView = (ListView) findViewById(R.id.listview);

mInflater = LayoutInflater.from(this);

initData();

adapter = new MyAdapter();

mListView.setAdapter(adapter);

}

private void initData() {

persons = new ArrayList<Person>();

for(int i
= 0; i < 40;
i++){

Person person = new Person();

person.setAge(i);

person.setName("更深的蓝");

if(i
% 2 == 0){

person.setType(0);

} else {

person.setType(1);

}

persons.add(person);

}

}

private class MyAdapter extends BaseAdapter{

@Override

public int getCount() {

return persons.size();

}

@Override

public Object getItem(int position) {

return persons.get(position);

}

@Override

public long getItemId(int position) {

return position;

}

@Override

public int getItemViewType(int position) {

if(persons.get(position).getType()
== 0){

return LEFT;

}

return RIGHT;

}

@Override

public int getViewTypeCount() {

return TYPE_COUNT;

}

@Override

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

ViewHolder mHolder;

Person person = persons.get(position);

if(getItemViewType(position)
== LEFT) {

if (convertView
== null) {

mHolder = new ViewHolder();

convertView = mInflater.inflate(R.layout.item_left, null);

mHolder.tv_username = (TextView) convertView.findViewById(R.id.tv_username);

mHolder.tv_age = (TextView) convertView.findViewById(R.id.tv_age);

convertView.setTag(mHolder);

} else {

mHolder = (ViewHolder) convertView.getTag();

}

mHolder.tv_username.setText(person.getName());

mHolder.tv_age.setText(String.valueOf(person.getAge()));

} else {

if(convertView
== null){

mHolder = new ViewHolder();

convertView = mInflater.inflate(R.layout.item_right, null);

mHolder.tv_username = (TextView) convertView.findViewById(R.id.tv_username);

mHolder.tv_age = (TextView) convertView.findViewById(R.id.tv_age);

convertView.setTag(mHolder);

}else{

mHolder = (ViewHolder) convertView.getTag();

}

mHolder.tv_username.setText(person.getName());

mHolder.tv_age.setText(String.valueOf(person.getAge()));

}

return convertView;

}

private class ViewHolder
{

TextView tv_username;

TextView tv_age;

}

}

}

Person.java

[java] view
plaincopyprint?

package com.jackie.wechat;

public class Person {

private String name;

private int age;

private int type;

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public int getAge() {

return age;

}

public void setAge(int age) {

this.age = age;

}

public int getType() {

return type;

}

public void setType(int type) {

this.type = type;

}

}

item_left.xml

[html] view
plaincopyprint?

<?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="vertical"

android:background="#ffffff"

>

<RelativeLayout

android:layout_width="fill_parent"

android:layout_height="45dp"

>

<TextView

android:id="@+id/tv_username"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:textSize="16sp"

android:textColor="#123456"

android:layout_centerVertical="true"

android:layout_alignParentLeft="true"

/>

<TextView

android:id="@+id/tv_age"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:textSize="16sp"

android:textColor="#123456"

android:layout_centerVertical="true"

android:layout_toRightOf="@id/tv_username"

android:layout_marginLeft="20dp"

/>

</RelativeLayout>

</RelativeLayout>

item_right.xml

[java] view
plaincopyprint?

<?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="vertical"

android:background="#ffffff"

>

<RelativeLayout

android:layout_width="fill_parent"

android:layout_height="45dp"

>

<TextView

android:id="@+id/tv_username"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:textSize="16sp"

android:textColor="#123456"

android:layout_centerVertical="true"

android:layout_alignParentRight="true"

/>

<TextView

android:id="@+id/tv_age"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:textSize="16sp"

android:textColor="#123456"

android:layout_centerVertical="true"

android:layout_toLeftOf="@id/tv_username"

android:layout_marginRight="20dp"

/>

</RelativeLayout>

</RelativeLayout>