微信聊天气泡UI实现

package com.ericssonlabs.chatdemo; import java.util.ArrayList; import java.util.List; 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.view.Window; import android.widget.BaseAdapter; import android.widget.Button; import android.widget.EditText; import android.widget.ImageView; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; public class ChatDemoActivity extends Activity { private Button sendButton = null; private EditText contentEditText = null; private ListView chatListView = null; private List<ChatEntity> chatList = null; private ChatAdapter chatAdapter = null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE); setContentView(R.layout.main); contentEditText = (EditText) this.findViewById(R.id.et_content); sendButton = (Button) this.findViewById(R.id.btn_send); chatListView = (ListView) this.findViewById(R.id.listview); chatList = new ArrayList<ChatEntity>(); ChatEntity chatEntity = null; for (int i = 0; i < 2; i++) { chatEntity = new ChatEntity(); if (i % 2 == 0) { chatEntity.setComeMsg(false); chatEntity.setContent("Hello"); chatEntity.setChatTime("2012-09-20 15:12:32"); }else { chatEntity.setComeMsg(true); chatEntity.setContent("Hello,nice to meet you!"); chatEntity.setChatTime("2012-09-20 15:13:32"); } chatList.add(chatEntity); } chatAdapter = new ChatAdapter(this,chatList); chatListView.setAdapter(chatAdapter); sendButton.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { if (!contentEditText.getText().toString().equals("")) { //发送消息 send(); }else { Toast.makeText(ChatDemoActivity.this, "Content is empty", Toast.LENGTH_SHORT).show(); } } }); } private void send(){ ChatEntity chatEntity = new ChatEntity(); chatEntity.setChatTime("2012-09-20 15:16:34"); chatEntity.setContent(contentEditText.getText().toString()); chatEntity.setComeMsg(false); chatList.add(chatEntity); chatAdapter.notifyDataSetChanged(); chatListView.setSelection(chatList.size() - 1); contentEditText.setText(""); } private class ChatAdapter extends BaseAdapter{ private Context context = null; private List<ChatEntity> chatList = null; private LayoutInflater inflater = null; private int COME_MSG = 0; private int TO_MSG = 1; public ChatAdapter(Context context,List<ChatEntity> chatList){ this.context = context; this.chatList = chatList; inflater = LayoutInflater.from(this.context); } @Override public int getCount() { return chatList.size(); } @Override public Object getItem(int position) { return chatList.get(position); } @Override public long getItemId(int position) { return position; } @Override public int getItemViewType(int position) { // 区别两种view的类型，标注两个不同的变量来分别表示各自的类型 ChatEntity entity = chatList.get(position); if (entity.isComeMsg()) { return COME_MSG; }else{ return TO_MSG; } } @Override public int getViewTypeCount() { // 这个方法默认返回1，如果希望listview的item都是一样的就返回1，我们这里有两种风格，返回2 return 2; } @Override public View getView(int position, View convertView, ViewGroup parent) { ChatHolder chatHolder = null; if (convertView == null) { chatHolder = new ChatHolder(); if (chatList.get(position).isComeMsg()) { convertView = inflater.inflate(R.layout.chat_from_item, null); }else { convertView = inflater.inflate(R.layout.chat_to_item, null); } chatHolder.timeTextView = (TextView) convertView.findViewById(R.id.tv_time); chatHolder.contentTextView = (TextView) convertView.findViewById(R.id.tv_content); chatHolder.userImageView = (ImageView) convertView.findViewById(R.id.iv_user_image); convertView.setTag(chatHolder); }else { chatHolder = (ChatHolder)convertView.getTag(); } chatHolder.timeTextView.setText(chatList.get(position).getChatTime()); chatHolder.contentTextView.setText(chatList.get(position).getContent()); chatHolder.userImageView.setImageResource(chatList.get(position).getUserImage()); return convertView; } private class ChatHolder{ private TextView timeTextView; private ImageView userImageView; private TextView contentTextView; } } }