我的应用程序将数据发送到服务器。在用户处于信号不良区域之前，它通常可以正常工作。如果用户处于信号良好的区域，则以下代码可以正常工作并发送数据。
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
.
信号不良区域的应用程序往往会显示进度条几分钟，然后再显示一段时间的黑屏，从而使应用程序无法使用。
我认为解决此问题的方法是执行以下操作。
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();
}
这将导致 AsyncTask 在 10 秒后取消，但在执行时会出现黑屏，直到发送数据，然后是进度条几毫秒。
有没有办法在执行 AsyncTask.get() 时显示进度条？
提前致谢。马特。
还有什么想法为什么当用户处于不良信号区域时会出现黑屏，因此服务器没有响应。这个 senario 似乎会导致应用程序出现很多问题，因为它的行为是不寻常的，例如在以后发送额外的交易。
[编辑1]
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;
}
}