我用 AsyncTask 建立了一个聊天室来接收消息,所以它总是检查即将到来的消息并将其显示给客户端,但代码似乎不像我希望的那样工作。
在客户端只显示所有旧数据,新数据不显示。因为当我尝试从服务器发送消息时,新数据没有显示在客户端中。
我对这个问题感到困惑,真的需要帮助。任何人请帮助我,谢谢。
用于接收的 AsyncTask
public class ReceivedTask extends AsyncTask<String, String, String> {
@Override
protected void onPreExecute() {
}
@Override
protected String doInBackground(String... arg0) {
// TODO Auto-generated method stub
try{
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(SERVER_URL);
ArrayList<NameValuePair> param = new ArrayList<NameValuePair>();
//add parameter
httpPost.setEntity(new UrlEncodedFormEntity(param));
HttpResponse httpRespose = httpClient.execute(httpPost);
HttpEntity httpEntity = httpRespose.getEntity();
//read content
InputStream in = httpEntity.getContent();
BufferedReader read = new BufferedReader(new InputStreamReader(in));
String content = "";
String line = "";
while((line = read.readLine())!=null){
content += line;
}
Log.d("ADBUG", "content: "+content);
//json
if(!content.equals("null")){
try{
JSONArray jArr = new JSONArray(content);
//String messages="";
for(int i=0; i < jArr.length() ; i++){
JSONObject jObj = jArr.getJSONObject(i);
String message = jObj.getString("message");
showMessage(message, false);
}
}catch(JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
else{
Toast.makeText(ChatRoom.this, "Error", Toast.LENGTH_LONG).show();
}
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
}
整个代码
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.chatpage);
messagesContainer = (ViewGroup) findViewById(R.id.messagesContainer);
scrollContainer = (ScrollView) findViewById(R.id.scrollContainer);
Button sendMessageButton = (Button) findViewById(R.id.sendButton);
Bundle bundle = this.getIntent().getExtras();
/*final String paramnama = bundle.getString("nama");*/
messageText = (EditText) findViewById(R.id.messageEdit);
meLabel = (TextView) findViewById(R.id.meLabel);
friendLabel = (TextView) findViewById(R.id.friendLabel);
meLabel.setText("me");
final String param1 = bundle.getString("keyCourseId");
final String param2 = bundle.getString("keyUserId");
final String param3 = bundle.getString("keyChatsId");
String param4 = bundle.getString("keyMessagesId");
sendMessageButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
//for send part already works fine
});
HttpURLConnection connection;
URL url = null;
try{
linkurl = new Koneksi(this);
SERVER_URL = linkurl.getUrl();
SERVER_URL += "/mobile/ChatRoom.php?idu="+param2+"&idch="+param3;
url = new URL(SERVER_URL);
connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
connection.setRequestMethod("POST");
new ReceivedTask().execute();
}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public class ReceivedTask extends AsyncTask<String, String, String> {
@Override
protected void onPreExecute() {
}
@Override
protected String doInBackground(String... arg0) {
// TODO Auto-generated method stub
try{
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(SERVER_URL);
ArrayList<NameValuePair> param = new ArrayList<NameValuePair>();
//add parameter
httpPost.setEntity(new UrlEncodedFormEntity(param));
HttpResponse httpRespose = httpClient.execute(httpPost);
HttpEntity httpEntity = httpRespose.getEntity();
//read content
InputStream in = httpEntity.getContent();
BufferedReader read = new BufferedReader(new InputStreamReader(in));
String content = "";
String line = "";
while((line = read.readLine())!=null){
content += line;
}
Log.d("ADBUG", "content: "+content);
//json
if(!content.equals("null")){
try{
JSONArray jArr = new JSONArray(content);
// String messages="";
for(int i=0; i < jArr.length() ; i++){
JSONObject jObj = jArr.getJSONObject(i);
String message = jObj.getString("message");
showMessage(message, false);
}
}catch(JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
else{
Toast.makeText(ChatRoom.this, "Error", Toast.LENGTH_LONG).show();
}
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
}
public void showMessage(String message, boolean leftSide) {
final TextView textView = new TextView(ChatRoom.this);
textView.setTextColor(Color.BLACK);
textView.setText(message);
int bgRes = R.drawable.left_message_bg;
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
if (!leftSide) {
bgRes = R.drawable.right_message_bg;
params.gravity = Gravity.RIGHT;
}
textView.setLayoutParams(params);
textView.setBackgroundResource(bgRes);
runOnUiThread(new Runnable() {
@Override
public void run() {
messagesContainer.addView(textView);
// Scroll to bottom
if (scrollContainer.getChildAt(0) != null) {
scrollContainer.scrollTo(scrollContainer.getScrollX(), scrollContainer.getChildAt(0).getHeight());
}
scrollContainer.fullScroll(View.FOCUS_DOWN);
}
});
}