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我的應用程序發送數據到服務器。它通常工作正常，直到用戶處於不良信號區域。如果用戶處於良好的信號區域，則以下代碼可正常工作併發送數據。AsyncTask.get（）沒有進度條
String[] params = new String[]{compID, tagId, tagClientId, carerID,
formattedTagScanTime, formattedNowTime, statusForWbService, getDeviceName(), tagLatitude, tagLongitude};
AsyncPostData apd = new AsyncPostData();
apd.execute(params);
。
private class AsyncPostData extends AsyncTask<String, Void, String> {
ProgressDialog progressDialog;
String dateTimeScanned;
@Override
protected void onPreExecute()
{
// progressDialog= ProgressDialog.show(NfcscannerActivity.this,
// "Connecting to Server"," Posting data...", true);
int buildVersionSdk = Build.VERSION.SDK_INT;
int buildVersionCodes = Build.VERSION_CODES.GINGERBREAD;
Log.e(TAG, "buildVersionSdk = " + buildVersionSdk
+ "buildVersionCodes = " + buildVersionCodes);
int themeVersion;
if (Build.VERSION.SDK_INT > Build.VERSION_CODES.GINGERBREAD) {
themeVersion = 2;
}else{
themeVersion = 1;
}
progressDialog = new ProgressDialog(NfcscannerActivity.this, themeVersion);
progressDialog.setTitle("Connecting to Server");
progressDialog.setMessage(" Sending data to server...");
progressDialog.setIndeterminate(true);
try{
progressDialog.show();
}catch(Exception e){
//ignore
}
};
@Override
protected String doInBackground(String... params) {
Log.e(TAG, "carerid in doinbackground = " + params[3] + " dateTimeScanned in AsyncPost for the duplecate TX = " + params[4]);
dateTimeScanned = params[4];
return nfcscannerapplication.loginWebservice.postData(params[0], params[1], params[2], params[3], params[4],
params[5], params[6], params[7] + getVersionName(), params[8], params[9]);
}
@Override
protected void onPostExecute(String result)
{
super.onPostExecute(result);
try{
progressDialog.dismiss();
}catch(Exception e){
//ignore
}
if(result != null && result.trim().equalsIgnoreCase("OK") ){
Log.e(TAG, "about to update DB with servertime");
DateTime sentToServerAt = new DateTime();
nfcscannerapplication.loginValidate.updateTransactionWithServerTime(sentToServerAt,null);
nfcscannerapplication.loginValidate.insertIntoDuplicateTransactions(dateTimeScanned);
tagId = null;
tagType = null;
tagClientId = null;
//called to refresh the unsent transactions textview
onResume();
}else if(result != null && result.trim().equalsIgnoreCase("Error: TX duplicated")){
Log.e(TAG, "response from server is Duplicate Transaction ");
//NB. the following time may not correspond exactly with the time on the server
//because this TX has already been processed but the 'OK' never reached the phone,
//so we are just going to update the phone's DB with the DupTX time so the phone doesn't keep
//sending it.
DateTime sentToServerTimeWhenDupTX = new DateTime();
nfcscannerapplication.loginValidate.updateTransactionWithServerTime(sentToServerTimeWhenDupTX,null);
tagId = null;
tagType = null;
tagClientId = null;
}else{
Toast.makeText(NfcscannerActivity.this,
"No phone signal or server problem",
Toast.LENGTH_LONG).show();
}
}
}//end of AsyncPostData
。
不良信號區域的應用程序往往會顯示幾分鐘的進度條，然後顯示一段時間的黑屏，導致應用程序無法使用。
我想過解決這個問題的方法是做以下事情。
String[] params = new String[]{compID, tagId, tagClientId, carerID,
formattedTagScanTime, formattedNowTime, statusForWbService, getDeviceName(), tagLatitude, tagLongitude};
AsyncPostData apd = new AsyncPostData();
try {
apd.execute(params).get(10, TimeUnit.SECONDS);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ExecutionException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (TimeoutException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
這將導致的AsyncTask至10秒後取消，但因爲它正在執行有一個黑色的屏幕，直到數據被髮送，然後由進度幾的毫秒。
有沒有辦法在執行AsyncTask.get（）時顯示進度條？
在此先感謝。馬特。
也有任何想法爲什麼當用戶處於不良信號區域並因此沒有來自服務器的響應時出現黑屏。這塞納里奧似乎導致應用程序很多的問題，其後行爲是不尋常的，像以後發送額外的交易。
[EDIT1]
public class SignalService extends Service{
NfcScannerApplication nfcScannerApplication;
TelephonyManager SignalManager;
PhoneStateListener signalListener;
private static final int LISTEN_NONE = 0;
private static final String TAG = SignalService.class.getSimpleName();
@Override
public void onCreate() {
super.onCreate();
// TODO Auto-generated method stub
Log.e(TAG, "SignalService created");
nfcScannerApplication = (NfcScannerApplication) getApplication();
signalListener = new PhoneStateListener() {
public void onSignalStrengthChanged(int asu) {
//Log.e("onSignalStrengthChanged: " , "Signal strength = "+ asu);
nfcScannerApplication.setSignalStrength(asu);
}
};
}
@Override
public void onDestroy() {
super.onDestroy();
// TODO Auto-generated method stub
Log.e(TAG, "SignalService destroyed");
SignalManager.listen(signalListener, LISTEN_NONE);
}
@Override
public void onStart(Intent intent, int startId) {
super.onStart(intent, startId);
// TODO Auto-generated method stub
Log.e(TAG, "SignalService in onStart");
SignalManager = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
SignalManager.listen(signalListener, PhoneStateListener.LISTEN_SIGNAL_STRENGTH);
}
@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
}
使用'get（）'只會使UX變差：[AsyncTask運行時出現黑屏]（http://stackoverflow.com/a/15259698/2558882）。 – Vikram
mmm是的我知道它阻止了UI線程，但我不知道如何設置一個定時器上的cancell而不使用.get（）。 – turtleboy
是否有可能使用處理程序取消asynctask？ – turtleboy