仿写聊天气泡界面

首先利用listview+EditText+Button构建一个主布局

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.example.liaotian.MainActivity" >

<ListView
android:id="@+id/listview"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:divider="#0000">
</ListView>

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

<EditText
android:id="@+id/text"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:maxLines="2"/>

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


然后进行list_item布局的编写，这里把左布局和右布局写在同一个界面里，将来再通过调用setVisible方法进行隐藏来形成一左一右对话效果

<?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:orientation="vertical" >

<LinearLayout
android:id="@+id/left_layout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="left"
android:layout_marginLeft="10dp"
android:background="@drawable/from" >

<TextView
android:id="@+id/left"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:textColor="#080808" />
</LinearLayout>

<LinearLayout
android:id="@+id/right_layout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right"
android:layout_marginRight="10dp"
android:layout_marginTop="5dp"
android:background="@drawable/to" >

<TextView
android:id="@+id/right"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:textColor="#080808" />
</LinearLayout>

</LinearLayout>

布局书写完毕，然后进行java代码的书写，手写书写Msg.java

package com.example.liaotian;

public class Msg {

public static final int TYPE_SENT = 1;
public static final int TYPE_RECEIVED = 0;
private String content;
private int type;

public Msg(String content, int type) {
// TODO Auto-generated constructor stub
this.content = content;
this.type = type;
}

public String getContent() {
return this.content;
}

public int getType() {
return this.type;
}
}


继续是Adapter的编写

package com.example.liaotian;

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<Msg> {

private int resourceId;

public MsgAdapter(Context context, int resource, List<Msg> objects) {
super(context, resource, objects);
// TODO Auto-generated constructor stub
this.resourceId = resource;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
// return super.getView(position, convertView, parent);
Msg msg = getItem(position);
ViewHolder holder;
View view;
if (convertView == null) {
view = LayoutInflater.from(getContext()).inflate(resourceId, null);
holder = new ViewHolder();
holder.leftLayout = (LinearLayout) view
.findViewById(R.id.left_layout);
holder.rightLayout = (LinearLayout) view
.findViewById(R.id.right_layout);
holder.leftMsg = (TextView) view.findViewById(R.id.left);
holder.rightMsg = (TextView) view.findViewById(R.id.right);
view.setTag(holder);
} else {
view = convertView;
holder = (ViewHolder) view.getTag();
}

// 判断是收到还是发送的消息
if (msg.getType() == Msg.TYPE_RECEIVED) {
holder.leftLayout.setVisibility(View.VISIBLE);
holder.rightLayout.setVisibility(View.GONE);
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());
}
return view;
}

class ViewHolder {
LinearLayout leftLayout;
LinearLayout rightLayout;
TextView leftMsg;
TextView rightMsg;
}

}


最后是MainActivity的编写

package com.example.liaotian;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;

public class MainActivity extends Activity {

private ListView listview;
private EditText text;
private Button send;
private MsgAdapter adapter;
private List<Msg> msgList = new ArrayList<Msg>();

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

initMsgs();

adapter = new MsgAdapter(getApplicationContext(), R.layout.list_item,
msgList);
listview = (ListView) this.findViewById(R.id.listview);
listview.setAdapter(adapter);
text = (EditText) this.findViewById(R.id.text);
send = (Button) this.findViewById(R.id.send);

this.send.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
String content = text.getText().toString();
if (!"".equals(content)) {
Msg msg = new Msg(content, Msg.TYPE_SENT);
msgList.add(msg);
adapter.notifyDataSetChanged();
listview.setSelection(msgList.size());
text.setText("");
} else {
Toast.makeText(getApplicationContext(), "不准发送空消息",
Toast.LENGTH_SHORT).show();
}

}
});

}

private void initMsgs() {
Msg msg1 = new Msg("你好啊", Msg.TYPE_RECEIVED);
msgList.add(msg1);
Msg msg2 = new Msg("你好啊，逗比", Msg.TYPE_SENT);
msgList.add(msg2);
}

}


效果图（颜值略低。。。）：