我正在开发一个 Android 项目,我正在尝试集成 Cometd 提供的 PUSH
服务。框架。
现在,每当 Conversation
收到新消息时,我想通知 ChatMessagesActivity
,其中包含两个用户之间的消息列表。
现在,当其他用户向 Android 应用程序发送消息时,我想更新用户的 View 。我尝试通过在 adapter
上调用 notifyDataSetHasChanged()
来做到这一点,但是因为我在 View
线程之外调用它,所以我收到了一个错误.
该方法是静态的,因为新消息在 Conversation
类中接收,而消息在 ChatMessagesActivity
类中进行。对于两个类之间的通信,我创建了 2 个静态方法,它们充当用于发送和接收消息的双向桥梁。
我希望我已经清楚了,如果有任何疑问,请告诉我。
ChatMessagesActivity.java :
public class ChatMessagesActivity extends ApplicationDrawerLoader {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_chat_messages);
chatList = (ListView)findViewById(R.id.chatList);
new getPrivateChatsForUser(this).execute();
}
// IN the method below, I receive information from another activity.
public static void recieveUpdatedMessage(String channelName, Map<String, Object> input){
Boolean found = Arrays.asList(channelName.split(" ")).contains("chat");
if(found){
int processedChannelName = Integer.valueOf(channelName.replace("/chat/",""));
if(processedChannelName == groupAccountId){
// Here i tried calling adapter.NotifyDataSetchanged();.. Didn't fly.
}
}
}
// Async method retrieving messages.
public class getPrivateChatsForUser extends AsyncTask<Void, Void, ResponseEntity<RestReplies[]>> {
ChatMessagesActivity chatMessagesActivity = null;
getPrivateChatsForUser(ChatMessagesActivity chatMessagesActivity) {
this.chatMessagesActivity = chatMessagesActivity;
}
@Override
protected ResponseEntity<RestReplies[]> doInBackground(Void... params) {
// network connection related stuff, not relevant to problem
}
@Override
protected void onPostExecute(ResponseEntity<RestReplies[]> responseEntity) {
super.onPostExecute(responseEntity);
RestReplies[] restRepliesArray = responseEntity.getBody();
Collections.addAll(restRepliesList, restRepliesArray);
ArrayList<HashMap<String, String>> chatMessagesHashMapList = new ArrayList<HashMap<String, String>>();
for (RestReplies restReplies : restRepliesList) {
HashMap<String, String> chatMap = new HashMap<>();
chatMap.put(chatText, restReplies.getReplyText());
chatMap.put(firstName, restReplies.getReplyingPersonName());
chatMap.put(chatImage, restReplies.getSenderImage());
chatMap.put(privateChannel,"/service/person/"+String.valueOf(conversationId));
chatMessagesHashMapList.add(chatMap);
}
chatList = (ListView) findViewById(R.id.chatList);
chatMessagesAdapter = new ChatMessagesAdapter(chatMessagesActivity, chatMessagesHashMapList);
chatList.setAdapter(chatMessagesAdapter);
chatList.scrollTo(0, chatList.getHeight());
}
}
那么,我应该如何指示数据集已更改。适配器如何知道从何处以及如何获取已更改的数据集。谁能帮我解决这个问题。非常感谢...:-)
最佳答案
在您的适配器上使用广播接收器并在您的推送服务中使用 android LocalBroadcast 触发本地广播
private BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent)
{
if(intent.getAction().equals("MYREFRESH"))
{
notifiyDataSetChanged();
}
}
};
在适配器的构造函数中注册这个接收器
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction("MYREFRESH");
LocalBroadcastManager.getInstance(context).registerReceiver(broadReceiver, intentFilter);
在你的推送中如果你收到推送通知触发这个
Intent intent = new Intent();
intent.putExtra(...) //send any data to your adapter
Intent.setAction("myaction");
LocalBroadcastManager.getInstance(context).sendBroadcast(intent);
关于java - 安卓 : Inform adapter that data-set has changed from a static method,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/34047594/