<?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"
android:padding="10dp" >
<LinearLayout
android:id="@+id/left_layout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="left"
android:background="@drawable/message_left" >
<TextView
android:id="@+id/left_msg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_margin="10dp" />
</LinearLayout>
<LinearLayout
android:id="@+id/right_layout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right"
android:background="@drawable/message_right">
<TextView
android:id="@+id/right_msg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_margin="10dp" />
</LinearLayout>
</LinearLayout>
package com.example.chatapp;
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 textViewResourceId, List<Msg> objects) {
super(context, textViewResourceId, objects);
resourceId = textViewResourceId;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
Msg msg = getItem(position);
View view;
ViewHolder viewHolder;
if (convertView == null) {
view = LayoutInflater.from(getContext()).inflate(resourceId, null);
viewHolder = new ViewHolder();
viewHolder.leftLayout = (LinearLayout) view
.findViewById(R.id.left_layout);
viewHolder.rightLayout = (LinearLayout) view
.findViewById(R.id.right_layout);
viewHolder.leftMsg = (TextView) view.findViewById(R.id.left_msg);
viewHolder.rightMsg = (TextView) view.findViewById(R.id.right_msg);
view.setTag(viewHolder);
} else {
view = convertView;
viewHolder = (ViewHolder) view.getTag();
}
if (msg.getType() == Msg.TYPE_RECEIVED) {
viewHolder.leftLayout.setVisibility(View.VISIBLE);
viewHolder.rightLayout.setVisibility(View.GONE);
viewHolder.leftMsg.setText(msg.getContent());
}
if (msg.getType() == Msg.TYPE_SEND) {
viewHolder.rightLayout.setVisibility(View.VISIBLE);
viewHolder.leftLayout.setVisibility(View.GONE);
viewHolder.rightMsg.setText(msg.getContent());
}
return view;
}
class ViewHolder {
LinearLayout leftLayout;
LinearLayout rightLayout;
TextView leftMsg;
TextView rightMsg;
}
}
<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:background="#d8e0e8"
android:orientation="vertical" >
<ListView
android:id="@+id/msg_list_view"
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:layout_gravity="bottom"
android:orientation="horizontal" >
<EditText
android:id="@+id/input_text"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="5"
android:maxLines="2" />
<Button
android:id="@+id/sent_button"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:padding="3dp"
android:text="发送" />
</LinearLayout>
</LinearLayout>
package com.example.chatapp;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.os.Bundle;
import android.view.Window;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
public class MainActivity extends Activity {
private ListView msgListView;
private EditText inputText;
private Button sentButton;
private MsgAdapter msgAdapter;
private List<Msg> msgList = new ArrayList<Msg>();
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
initMsgs();
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);
msgAdapter = new MsgAdapter(MainActivity.this, R.layout.msg_item,
msgList);
msgListView = (ListView) findViewById(R.id.msg_list_view);
msgListView.setAdapter(msgAdapter);
}
private void initMsgs() {
Msg m1 = new Msg("Hello~", Msg.TYPE_RECEIVED);
msgList.add(m1);
Msg m2 = new Msg("Who are you?", Msg.TYPE_SEND);
msgList.add(m2);
Msg m3 = new Msg("I'm your father", Msg.TYPE_RECEIVED);
msgList.add(m3);
}
}
package com.example.chatapp;
public class Msg {
public static final int TYPE_RECEIVED = 0;
public static final int TYPE_SEND = 1;
private String content;
private int type;
public Msg(String content, int type) {
this.content = content;
this.type = type;
}
public String getContent() {
return content;
}
public int getType() {
return type;
}
}
为什么消息框不会伸缩,是哪里出错了呢?