我正在开发一款聊天应用。 gcm服务正如预期的那样工作，聊天活动，但我现在遇到的问题是，每当设备向另一台设备发送消息时，我都会正确收到消息通知，但当我点击消息时我只看到一个空白列表发件人消息的视图。这些是我的代码：
Messaging Activity
public class Messaging extends Activity {
private static final String TAG = "ChatActivity";
private static final int MESSAGE_CANNOT_BE_SENT = 0;
private EditText messageText;
// private EditText messageHistoryText;
private ListView messageHistoryText;
private EditText chatText;
private ListView listView;
private ChatArrayAdapter chatArrayAdapter;
private Button sendMessageButton;
private IAppManager imService;
private boolean side = false;
private FriendInfo friend = new FriendInfo();
private ServiceConnection mConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName className, IBinder service) {
imService = ((IMService.IMBinder)service).getService();
}
public void onServiceDisconnected(ComponentName className) {
imService = null;
Toast.makeText(Messaging.this, R.string.local_service_stopped,
Toast.LENGTH_SHORT).show();
}
};
@Override
protected void onCreate(Bundle savedInstanceState)
{
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.messaging_screen); //messaging_screen);
messageHistoryText = (ListView) findViewById(R.id.listView1); //ListView
chatArrayAdapter = new ChatArrayAdapter(getApplicationContext(), R.layout.activity_chat_singlemessage);
messageHistoryText.setAdapter(chatArrayAdapter);
messageText = (EditText) findViewById(R.id.message);
messageText.requestFocus();
sendMessageButton = (Button) findViewById(R.id.sendMessageButton);
Bundle extras = this.getIntent().getExtras();
friend.userName = extras.getString(FriendInfo.USERNAME);
friend.ip = extras.getString(FriendInfo.IP);
friend.port = extras.getString(FriendInfo.PORT);
final String msg = extras.getString(FriendInfo.MESSAGE);
setTitle("Messaging with " + friend.userName);
messageText.setOnKeyListener(new OnKeyListener() {
public boolean onKey(View v, int keyCode, KeyEvent event) {
if ((event.getAction() == KeyEvent.ACTION_DOWN) && (keyCode == KeyEvent.KEYCODE_ENTER)) {
return sendChatMessage(friend.userName, msg);
}
return false;
}
});
if (msg != null)
{
this.sendChatMessage(friend.userName, msg); //Edit appendTo
((NotificationManager)getSystemService(NOTIFICATION_SERVICE)).cancel((friend.userName+msg).hashCode());
}
sendMessageButton.setOnClickListener(new View.OnClickListener() {
CharSequence message;
Handler handler = new Handler();
@Override
public void onClick(View arg0) {
sendChatMessage(imService.getUsername(), message.toString());
}
}
});
messageHistoryText.setTranscriptMode(AbsListView.TRANSCRIPT_MODE_ALWAYS_SCROLL);
messageHistoryText.setAdapter(chatArrayAdapter);
//to scroll the list view to bottom on data change
chatArrayAdapter.registerDataSetObserver(new DataSetObserver() {
@Override
public void onChanged() {
super.onChanged();
messageHistoryText.setSelection(chatArrayAdapter.getCount() - 1);
}
});
}
@Override
protected Dialog onCreateDialog(int id) {
int message = -1;
switch (id)
{
case MESSAGE_CANNOT_BE_SENT:
message = R.string.message_cannot_be_sent;
break;
}
if (message == -1)
{
return null;
}
else
{
return new AlertDialog.Builder(Messaging.this)
.setMessage(message)
.setPositiveButton(R.string.OK, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
/* User clicked OK so do some stuff */
}
})
.create();
}
}
@Override
protected void onPause() {
super.onPause();
unregisterReceiver(messageReceiver);
unbindService(mConnection);
FriendController.setActiveFriend(null);
}
@Override
protected void onResume()
{
super.onResume();
bindService(new Intent(Messaging.this, IMService.class), mConnection , Context.BIND_AUTO_CREATE);
IntentFilter i = new IntentFilter();
i.addAction(IMService.TAKE_MESSAGE);
registerReceiver(messageReceiver, i);
FriendController.setActiveFriend(friend.userName);
}
public class MessageReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent)
{
Bundle extra = intent.getExtras();
String username = extra.getString(FriendInfo.USERNAME);
String message = extra.getString(FriendInfo.MESSAGE);
if (username != null && message != null)
{
if (friend.userName.equals(username)) {
sendChatMessage(username, message); //Edit
}
else {
if (message.length() > 15) {
message = message.substring(0, 15);
}
Toast.makeText(Messaging.this, username + " says '"+
message + "'",
Toast.LENGTH_SHORT).show();
}
}
}
};
private MessageReceiver messageReceiver = new MessageReceiver();
private boolean sendChatMessage(String username, String message) {
chatArrayAdapter.add(new ChatMessage(side, messageText.getText().toString()));
messageText.setText("");
side = !side;
return true;
}
}
message_chat.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:padding="10dip"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="10dip"
android:text="Messages:"
android:id="@+id/textView" />
<ListView
android:id="@+id/listView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="80dp"
>
</ListView>
<RelativeLayout android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="4"
android:weightSum="1"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true">
<EditText android:id="@+id/message"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:gravity="top"
android:layout_toLeftOf="@+id/sendMessageButton"
android:layout_toStartOf="@+id/sendMessageButton" />
<Button android:id="@+id/sendMessageButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Send"
android:layout_gravity="right"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true" />
</RelativeLayout>
</RelativeLayout>
ChatArrayAdapter Class
public class ChatArrayAdapter extends ArrayAdapter<ChatMessage> {
private TextView messagel;
private List<ChatMessage> chatMessageList = new ArrayList<ChatMessage>();
private LinearLayout singleMessageContainer;
@Override
public void add(ChatMessage object) {
chatMessageList.add(object);
super.add(object);
}
public ChatArrayAdapter(Context context, int textViewResourceId) {
super(context, textViewResourceId);
}
public int getCount() {
return this.chatMessageList.size();
}
public ChatMessage getItem(int index) {
return this.chatMessageList.get(index);
}
public View getView(int position, View convertView, ViewGroup parent) {
ChatMessage chatMessageObj = getItem(position);
View row = convertView;
if (row == null) {
LayoutInflater inflater = (LayoutInflater) this.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (chatMessageObj.left) {
row = inflater.inflate(R.layout.right, parent, false);
}else{
row = inflater.inflate(R.layout.left, parent, false);
}
}
messagel = (TextView) row.findViewById(R.id.msgr);
messagel.setText(chatMessageObj.message);
return row;
}
public Bitmap decodeToBitmap(byte[] decodedByte) {
return BitmapFactory.decodeByteArray(decodedByte, 0, decodedByte.length);
} }
Chat Message Class
public class ChatMessage {
public boolean left;
public String message;
public ChatMessage(boolean left, String message) {
super();
this.left = left;
this.message = message;
} }
left.xml is same as right.xml in code just layout_gravity difference
<?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">
<TextView
android:id="@+id/msgr"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="left"
android:layout_marginBottom="5dp"
android:layout_marginRight="20dp"
android:background="@drawable/textview"
android:paddingBottom="8dp"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:paddingTop="5dp"
android:text="Sampleleft"
android:textColor="#000" />
</RelativeLayout>
提前致谢。亲切的问候，史蒂夫。