So i'm getting an error in my program with my Google Speech API. The error is "Not all paths return a value" as the title suggest.
Here is the code (2 peices)(Same error)
public static SpeechInputResult ProcessFlacFile(string FlacFileName, int BIT_RATE = DEFAULT_BIT_RATE, string language = DEFAULT_LANGUAGE, uint maxresults = 1)
{
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create("https://www.google.com/speech-api/v1/recognize?xjerr=1" + "&client=" + client + "&lang=" + language + "&maxresults=" + maxresults + "&pfilter=0");
FileStream fStream = new FileStream(FlacFileName, FileMode.Open, FileAccess.Read);
request.Proxy = null;
request.Timeout = 60000;
request.KeepAlive = true;
request.Method = "POST";
request.ContentType = "audio/x-flac; rate=8000";
//bitrate must = .flac file
request.UserAgent = client;
FileInfo fInfo = new FileInfo(FlacFileName);
long numbytes = fInfo.Length;
byte[] data = null;
using (FileStream fstream = new FileStream(FlacFileName, FileMode.Open, FileAccess.Read))
data = new byte[fstream.Length];
fStream.Read(data, 0, Convert.ToInt32(fStream.Length));
fStream.Close();
using (Stream wrStream = request.GetRequestStream())
{
wrStream.Write(data, 0, data.Length);
}
try
{
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
dynamic resp = response.GetResponseStream();
if (resp != null)
{
StreamReader sr = new StreamReader(resp);
MessageBox.Show(sr.ReadToEnd());
resp.Close();
resp.Dispose();
}
}
catch (System.Exception ee)
{
MessageBox.Show(ee.Message);
}
}
}
}
and 2nd piece here:
public class Hypothesis
{
public string utterance;
public double confidence = -1.0d;//-1 = No Value
public override string ToString()
{
return "'" +utterance + "'" + ((confidence == -1) ? "" : "#" + confidence);
}
public List<Hypothesis> hypotheses = new List<Hypothesis>();
public Hypothesis getBestHypothesis()
{
if (hypotheses.Count() <=0)
return null;
Hypothesis H = hypotheses[0];
foreach (Hypothesis h in hypotheses)
{
if (h.confidence>=H.confidence)
{
H = h;
}
return H;
}
}
Both code have the same error and it only seems to happen if I a certain variable name to be the same name as another variable (FlacFileName, to be exact). If you guys could tell me why this is happening that would be awesome thanks!
Your method signature
public static SpeechInputResult ProcessFlacFile(string FlacFileName, int BIT_RATE = DEFAULT_BIT_RATE, string language = DEFAULT_LANGUAGE, uint maxresults = 1)
states you will be returning a SpeechInputResult but you have no return statement.
You should either change the signature to void or actually return a value.
In the second instance, you need a return statement after the for loop.
Like everyone mentioned, add a return statement to the end of the first method. Just a return null; or whatever's appropriate in your situation. Actually, you have no other return statements in that method at all, so it's not a "not all paths return a value" situation like the second... you may just want to change the signature from SpeechInputResult to void.
In the second method, it seems like you have your bases covered, because:
You're returning null if hypotheses is empty and
You're returning the hypotheses with the largest "confidence" if it's not empty
But the compiler isn't smart enough to see that. Try moving return null; to the end. The only way you'll make it there is if there are no elements in the list and the foreach loop doesn't run.
public Hypothesis getBestHypothesis()
{
if (hypotheses.Any())
{
Hypothesis H = hypotheses[0];
foreach (Hypothesis h in hypotheses)
{
if (h.confidence >= H.confidence)
{
H = h;
}
return H;
}
}
return null;
}
Also, that whole second method could be reduced (with the help of LINQ):
return hypotheses.OrderByDescending(x => x.confidence).FirstOrDefault();
i find that in your code you have to return SpeechInputResult but there is no where you are using return statement.
It is preferred that you use return SpeechInputResult in your code
other wise put your function as below if your are not willing to return anything to it.
public static void ProcessFlacFile(string FlacFileName, int BIT_RATE = DEFAULT_BIT_RATE, string language = DEFAULT_LANGUAGE, uint maxresults = 1)
you can use void instead of the class SpeechInputResult as in the above code if you want to be it without the error in this case.
in the second piece of code you only instantiated the code. ie declared and directly used it
you must have something assigned to the object you created so that you can perform operation in the foreach.
in this case hypotheses doesnt have any thing inside it.
Also you have written return statement inside the foreach loop where as the focus will never go inside the foreach loop.
First you assign something to hypotheses so that it has value in it and then perform actions.
First block of code does not have any return statement. In the second code block , put a dummy return statement outside the for loop.
In your first method, you declared in signature that, it will be returning instance of typeSpeechInputResult, while you are not returning it from body.
And, in second method, you are returning from inside foreach loop, but what if your hypotheses list doesn't have any element? You should also be returning either a default value from outside the foreach loop or you should throw an exception if it isn't your expected behaviour.
ProcessFlacFile method in the above code should return a type SpeechInputResult object in all cases.
You can return the object after try and catch as
try
{
}
catch
{
}
return SpeechInputResultObj
or
return SpeechInputResult object in both try and catch statement
try
{
....
return SpeechInputResultObj;
}
catch
{
....
return SpeechInputResultObj;
}
Related
I have code that basically opens a webpage + .ts file from a link and repeats it, but the problem is it increases memory usage each time and never removes the old data. After 2 Hours it uses more than 2GB.
Any ideas on how I can fix this issue?
I'm using "Leaf.Xnet" Library for requests and this is how I create my threads:
new Thread(new ThreadStart(WebHelper.Check)).Start();
Main code:
public static void Check()
{
HttpRequest request = null;
while (Form1.isRuning)
{
Application.DoEvents();
try
{
request = new HttpRequest();
if (!ProxyManager.updating)
{
switch (ProxyManager.curProxyType)
{
case ProxyManager.proxyType.http:
request.Proxy = HttpProxyClient.Parse(ProxyManager.NextProxy(ProxyManager.proxyType.http));
break;
case ProxyManager.proxyType.socks4:
request.Proxy = Socks4ProxyClient.Parse(ProxyManager.NextProxy(ProxyManager.proxyType.socks4));
break;
case ProxyManager.proxyType.socks5:
request.Proxy = Socks5ProxyClient.Parse(ProxyManager.NextProxy(ProxyManager.proxyType.socks5));
break;
}
}
else
{
Thread.Sleep(2000);
Check();
}
request.UserAgentRandomize();
request.AddHeader(HttpHeader.Referer, "https://somesite.com");
request.KeepAlive = true;
request.ConnectTimeout = Form1.timeOut;
request.Reconnect = true;
string html = request.Get(Form1.link, null).ToString();
string auth = html.Substring(",[{\"src\":\"", "\"");
string sign = html.Substring("144p.apt?wmsAuthSign=", "\"");
if (auth != null && sign != null)
{
string auth2 = "";
foreach (char item in auth)
{
if (item != '\\')
auth2 += item;
}
auth = auth2;
string cdn = auth.Substring("https://", ".");
string id = auth.Substring("video/", "-");
if (cdn != null && id != null)
{
Random rnd = new Random();
request.Get(auth);
Form1.sended++;
WriteStat();
}
html = null;
auth = null;
auth2 = null;
sign = null;
}
}
catch (HttpException)
{
Check();
}
catch (ProxyException)
{
Check();
}
}
}
I am not entirely sure if this will fix your problem but for each thread that you start, you pretty much call an infinite number of executions of Check(). Since Check contains a while loop, the thread will run whatever is in side forever anyway, and now you're calling the method again on top of it. This means that everything that was created in the scope of the Check method will not be garbage collected and will increase your memory.
Replace all calls to Check() with continue which will stop the execution in the while loop and start over.
Also, consider not using Threads, but instead use Tasks.
Also you do not dispose your HttpRequest.
Long story short. ;
I have a class named Scope. And this class contains all logic for scope operations etc. It also starts backround thread that constantly read serial port data (in my case events was unreliable):
Thread BackgroundReader = new Thread(ReadBuffer);
BackgroundReader.IsBackground = true;
BackgroundReader.Start();
private void ReadBuffer()
{
SerialPort.DiscardInBuffer();
while (!_stopCapture)
{
int bufferSize = SerialPort.BytesToRead;
byte[] buffer = new byte[bufferSize];
if(bufferSize > 5)
{
SerialPort.Read(buffer, 0, bufferSize);
Port_DataReceivedEvent(buffer, null);
}
Thread.Sleep(_readDelay);
}
CurrentBuffer = null;
}
In Scope class there is a public field named Buffer
public byte[] Buffer
{
get
{
return CurrentBuffer;
}
}
And here is event fired while there is new data readed
private void Port_DataReceivedEvent(object sender, EventArgs e)
{
//populate buffer
Info(sender, null);
CurrentBuffer = ((byte[])sender);
foreach(byte data in CurrentBuffer)
{
DataBuffer.Enqueue(data);
}
if (DataBuffer.Count() > _recordLength)
{
GenerateFrame(DataBuffer.ToArray());
DataBuffer.Clear(); ;
}
}
To make code more manageable, I splitted it in several classes. One of this classes is for searching specific data pattern in current stream and create specific object from this data. This code works in way that send to serial port specific command and expect return frame. If reponse is not received or not ok, send is performed again and again until correct response arrives or there will be timeout. Response is expected to be in current buffer. Those strange string manipulation is for debug purposes.
public class GetAcknowledgedFrame
{
byte[] WritedData;
string lastEx;
string stringData;
public DataFrame WriteAcknowledged(Type SendType, Type ReturnType, JyeScope scope)
{
var stopwatch = new Stopwatch();
stopwatch.Restart();
while (stopwatch.ElapsedMilliseconds < scope.TimeoutTime)
{
try
{
if (SendType == typeof(GetParameters))
{
WriteFrame(new ScopeControlFrames.GetParameters(), scope.SerialPort);
}
else if(SendType == typeof(GetConfig))
{
WriteFrame(new ScopeControlFrames.GetConfig(), scope.SerialPort);
}
else if (SendType == typeof(EnterUSBScopeMode))
{
WriteFrame(new ScopeControlFrames.EnterUSBScopeMode(), scope.SerialPort);
}
return ReturnFrame(ReturnType, scope.Buffer, scope.TimeoutTime);
}
catch (InvalidDataFrameException ex)
{
lastEx = ex.Message;
System.Threading.Thread.Sleep(10);
}
}
stringData = "";
foreach (var data in scope.Buffer)
{
stringData += data + ",";
}
stringData.Remove(stringData.Length - 1);
throw new TimeoutException($"Timeout while waiting for frame acknowledge: " + SendType.ToString() + ", " + ReturnType.ToString() + Environment.NewLine+ "Add. err: "+lastEx);
}
private DataFrame ReturnFrame(Type FrameType, byte[] buffer, int timeoutTime)
{
if (FrameType == typeof(DataFrames.DSO068.CurrConfigDataFrame))
{
DataFrames.DSO068.CurrConfigDataFrame CurrConfig = new DataFrames.DSO068.CurrConfigDataFrame(buffer);
return CurrConfig;
}
else if (FrameType == typeof(DataFrames.DSO112.CurrConfigDataFrame))
{
DataFrames.DSO112.CurrConfigDataFrame CurrParam = new DataFrames.DSO112.CurrConfigDataFrame(buffer);
return CurrParam;
}
else if (FrameType == typeof(CurrParamDataFrame))
{
CurrParamDataFrame CurrParam = new CurrParamDataFrame(buffer);
return CurrParam;
}
else if (FrameType == typeof(DataBlockDataFrame))
{
DataBlockDataFrame CurrData = new DataBlockDataFrame(buffer);
return CurrData;
}
else if (FrameType == typeof(DataSampleDataFrame))
{
DataSampleDataFrame CurrData = new DataSampleDataFrame(buffer);
return CurrData;
}
else if (FrameType == typeof(ScopeControlFrames.ScopeReady))
{
ScopeControlFrames.ScopeReady ready = new ScopeControlFrames.ScopeReady(buffer);
return ready;
}
else
{
throw new InvalidOperationException("Wrong object type");
}
}
private bool WriteFrame(DataFrame frame, IStreamResource port)
{
WritedData = frame.Data;
port.Write(frame.Data, 0, frame.Data.Count());
return true;
}
}
From main class (and main thread) I call method in this class, for example:
var Ready = (ScopeControlFrames.ScopeReady)new GetAcknowledgedFrame().WriteAcknowledged
(typeof(ScopeControlFrames.EnterUSBScopeMode), typeof(ScopeControlFrames.ScopeReady), this);
The problem is when I pass "this" object (that has thread working in background) to my helper class. It seems like helper class not see changing data in this object. The problem started when I separate code of my helper class from main class.
My questions:
- I know that object are passed by reference, that means I think that when object is dynamically changing its state (in this case data buffer should changing while new data is received) all classes that has reference to this object are also seeing this changes. Maybe I'm missing something?
- I tried passing array (by ref), arrays are also reference types. But this not help me at all. Maybe I'm missing something?
I tried changing this class to static, it not helped.
Many thanks for help.
The code below;
Info(sender, null);
CurrentBuffer = ((byte[])sender);
is creating a new reference variable called CurrentBuffer. Any other code holding a reference 'pointer' to the CurrentBuffer value prior to this line of code will not get the new value of CurrentBuffer when its reset.
I was wondering if there is a way to programmatically check how many messages are in a private or public MSMQ using C#? I have code that checks if a queue is empty or not using the peek method wrapped in a try/catch, but I've never seen anything about showing the number of messages in the queue. This would be very helpful for monitoring if a queue is getting backed up.
You can read the Performance Counter value for the queue directly from .NET:
using System.Diagnostics;
// ...
var queueCounter = new PerformanceCounter(
"MSMQ Queue",
"Messages in Queue",
#"machinename\private$\testqueue2");
Console.WriteLine( "Queue contains {0} messages",
queueCounter.NextValue().ToString());
There is no API available, but you can use GetMessageEnumerator2 which is fast enough. Sample:
MessageQueue q = new MessageQueue(...);
int count = q.Count();
Implementation
public static class MsmqEx
{
public static int Count(this MessageQueue queue)
{
int count = 0;
var enumerator = queue.GetMessageEnumerator2();
while (enumerator.MoveNext())
count++;
return count;
}
}
I also tried other options, but each has some downsides
Performance counter may throw exception "Instance '...' does not exist in the specified Category."
Reading all messages and then taking count is really slow, it also removes the messages from queue
There seems to be a problem with Peek method which throws an exception
If you need a fast method (25k calls/second on my box), I recommend Ayende's version based on MQMgmtGetInfo() and PROPID_MGMT_QUEUE_MESSAGE_COUNT:
for C#
https://github.com/hibernating-rhinos/rhino-esb/blob/master/Rhino.ServiceBus/Msmq/MsmqExtensions.cs
for VB
https://gist.github.com/Lercher/5e1af6a2ba193b38be29
The origin was probably http://functionalflow.co.uk/blog/2008/08/27/counting-the-number-of-messages-in-a-message-queue-in/ but I'm not convinced that this implementation from 2008 works any more.
We use the MSMQ Interop. Depending on your needs you can probably simplify this:
public int? CountQueue(MessageQueue queue, bool isPrivate)
{
int? Result = null;
try
{
//MSMQ.MSMQManagement mgmt = new MSMQ.MSMQManagement();
var mgmt = new MSMQ.MSMQManagementClass();
try
{
String host = queue.MachineName;
Object hostObject = (Object)host;
String pathName = (isPrivate) ? queue.FormatName : null;
Object pathNameObject = (Object)pathName;
String formatName = (isPrivate) ? null : queue.Path;
Object formatNameObject = (Object)formatName;
mgmt.Init(ref hostObject, ref formatNameObject, ref pathNameObject);
Result = mgmt.MessageCount;
}
finally
{
mgmt = null;
}
}
catch (Exception exc)
{
if (!exc.Message.Equals("Exception from HRESULT: 0xC00E0004", StringComparison.InvariantCultureIgnoreCase))
{
if (log.IsErrorEnabled) { log.Error("Error in CountQueue(). Queue was [" + queue.MachineName + "\\" + queue.QueueName + "]", exc); }
}
Result = null;
}
return Result;
}
//here queue is msmq queue which you have to find count.
int index = 0;
MSMQManagement msmq = new MSMQManagement() ;
object machine = queue.MachineName;
object path = null;
object formate=queue.FormatName;
msmq.Init(ref machine, ref path,ref formate);
long count = msmq.MessageCount();
This is faster than you selected one.
You get MSMQManagement class refferance inside "C:\Program Files (x86)\Microsoft SDKs\Windows" just brows in this address you will get it. for more details you can visit http://msdn.microsoft.com/en-us/library/ms711378%28VS.85%29.aspx.
I had real trouble getting the accepted answer working because of the xxx does not exist in the specified Category error. None of the solutions above worked for me.
However, simply specifying the machine name as below seems to fix it.
private long GetQueueCount()
{
try
{
var queueCounter = new PerformanceCounter("MSMQ Queue", "Messages in Queue", #"machineName\private$\stream")
{
MachineName = "machineName"
};
return (long)queueCounter.NextValue();
}
catch (Exception e)
{
return 0;
}
}
The fastest method I have found to retrieve a message queue count is to use the peek method from the following site:
protected Message PeekWithoutTimeout(MessageQueue q, Cursor cursor, PeekAction action)
{
Message ret = null;
try
{
ret = q.Peek(new TimeSpan(1), cursor, action);
}
catch (MessageQueueException mqe)
{
if (!mqe.Message.ToLower().Contains("timeout"))
{
throw;
}
}
return ret;
}
protected int GetMessageCount(MessageQueue q)
{
int count = 0;
Cursor cursor = q.CreateCursor();
Message m = PeekWithoutTimeout(q, cursor, PeekAction.Current);
{
count = 1;
while ((m = PeekWithoutTimeout(q, cursor, PeekAction.Next)) != null)
{
count++;
}
}
return count;
}
This worked for me. Using a Enumarator to make sure the queue is empty first.
Dim qMsg As Message ' instance of the message to be picked
Dim privateQ As New MessageQueue(svrName & "\Private$\" & svrQName) 'variable svrnme = server name ; svrQName = Server Queue Name
privateQ.Formatter = New XmlMessageFormatter(New Type() {GetType(String)}) 'Formating the message to be readable the body tyep
Dim t As MessageEnumerator 'declared a enumarater to enable to count the queue
t = privateQ.GetMessageEnumerator2() 'counts the queues
If t.MoveNext() = True Then 'check whether the queue is empty before reading message. otherwise it will wait forever
qMsg = privateQ.Receive
Return qMsg.Body.ToString
End If
If you want a Count of a private queue, you can do this using WMI.
This is the code for this:
// You can change this query to a more specific queue name or to get all queues
private const string WmiQuery = #"SELECT Name,MessagesinQueue FROM Win32_PerfRawdata_MSMQ_MSMQQueue WHERE Name LIKE 'private%myqueue'";
public int GetCount()
{
using (ManagementObjectSearcher wmiSearch = new ManagementObjectSearcher(WmiQuery))
{
ManagementObjectCollection wmiCollection = wmiSearch.Get();
foreach (ManagementBaseObject wmiObject in wmiCollection)
{
foreach (PropertyData wmiProperty in wmiObject.Properties)
{
if (wmiProperty.Name.Equals("MessagesinQueue", StringComparison.InvariantCultureIgnoreCase))
{
return int.Parse(wmiProperty.Value.ToString());
}
}
}
}
}
Thanks to the Microsoft.Windows.Compatibility package this also works in netcore/netstandard.
The message count in the queue can be found using the following code.
MessageQueue messageQueue = new MessageQueue(".\\private$\\TestQueue");
var noOFMessages = messageQueue.GetAllMessages().LongCount();
I designed my webpage to read a data string then display the results on labels in an html table. I am attempting to highlight the row that my database reads as a current order. My only problem is only one record is set to be active but they all highlight as if they were active. I use an array to set my data and I also use the label to get the ID I need (all is in code below). I have posted my method and where I use it in the asp page load. How can I fix my method to return correctly?
The implementing of the method in page load
if (lineData.IsCurrentOrderFind(L68.Text))
{
myTable.Rows[1].Cells[0].BgColor = "#FE2E2E";
myTable.Rows[1].Cells[1].BgColor = "#FE2E2E";
myTable.Rows[1].Cells[2].BgColor = "#FE2E2E";
myTable.Rows[1].Cells[3].BgColor = "#FE2E2E";
myTable.Rows[1].Cells[4].BgColor = "#FE2E2E";
}
Here is method that label above gets passed to
public bool IsCurrentOrderFind(string itemNumber)
{
StringBuilder sqlString = new StringBuilder();
sqlString.Append("SELECT * ");
sqlString.Append("FROM WorkOrder ");
sqlString.Append("WHERE LineNumber = " + ConfigurationManager.AppSettings["Line"] + " AND LineCompleted = 0 AND (ScaleGroup LIKE '%1' OR ScaleGroup LIKE '%3') ");
sqlString.Append(" AND CaseGenNum6 = #CaseGenNum6");
SqlDataReader reader = null;
SqlConnection dbConn = App_Code.DBHelper.getConnection();
SqlParameter[] parameters = new SqlParameter[] { new SqlParameter("#CaseGenNum6", itemNumber) };
try
{
reader = App_Code.DBHelper.executeQuery(dbConn, sqlString.ToString(), parameters);
while (reader.Read())
{
IsCurrentOrder = (reader["IsCurrentOrder"] != DBNull.Value && !string.IsNullOrEmpty(reader["IsCurrentOrder"].ToString())) ? true : false;
}
reader.Close();
reader.Dispose();
dbConn.Close();
dbConn.Dispose();
}
catch (Exception ex)
{
throw ex;
}
finally
{
if (dbConn != null)
{
try { dbConn.Close(); dbConn.Dispose(); }
catch { }
}
if (reader != null)
{
try { reader.Close(); reader.Dispose(); }
catch { }
}
}
if (IsCurrentOrder == true) I realize this is not necessary
{
return true;
}
else
{
return false;
}
}
The problem could be with this expression:
!string.IsNullOrEmpty(reader["IsCurrentOrder"].ToString())
Instead of calling ToString(), try simply casting it to a string:
!string.IsNullOrEmpty((string)reader["IsCurrentOrder"])
Possibly even better (the previous line might throw an exception if it's not really a string):
!string.IsNullOrEmpty(reader["IsCurrentOrder"] as string)
The reason being is that if the string is really null, calling ToString() will return a non-null string "null".
IsCurrentOrder is not declared locally. It seems to be declared at a higher scope. When you enter this function, nothing is initializing the variable (back to false). So, it is remaining at its last setting. Try this code instead:
public bool IsCurrentOrderFind(string itemNumber)
{
bool IsCurrentOrder = false;
//and the rest of your source code
the line
IsCurrentOrder = (reader["IsCurrentOrder"] != DBNull.Value && !string.IsNullOrEmpty(reader["IsCurrentOrder"].ToString())) ? true : false;
}
It's not actually checking the value of the field, only that it's not null or empty.
Try
if(
(reader["IsCurrentOrder"] != DBNull.Value
&&
!string.IsNullOrEmpty(reader["IsCurrentOrder"].ToString()))
)
{
IsCurrentOrder = reader["IsCurrentOrder"];
}
else
IsCurrentOrder = false;
I think there is a lot of refactoring you could do to this method though that will simplify the logic.
In my C# app I'm trying to feed into ReadLine() a simple text document with 7 digit strings separated line by line. What I'm attempting to do is grab the next 7 digit string each time the function is called. Here's what I have so far:
string invoiceNumberFunc()
{
string path = #"C:\Users\sam\Documents\GCProg\testReadFile.txt";
try
{
using (StreamReader sr = new StreamReader(path))
{
invoiceNumber = sr.ReadLine();
}
}
catch (Exception exp)
{
Console.WriteLine("The process failed: {0}", exp.ToString());
}
return invoiceNumber;
}
How do I advance to the next line each time the invoiceNumberFunc() is called?
Thanks in advance.
You'd need to keep hold of the StreamReader between calls, either passing it into the method as a new parameter or making it a member variable of the class.
Personally I prefer the idea of it becoming a parameter, so that it never ends up as a member variable - that makes the life-time easier to manage:
void DoStuff()
{
string path = #"C:\Users\sam\Documents\GCProg\testReadFile.txt";
using (StreamReader sr = new StreamReader(path))
{
while (keepGoing) // Whatever logic you have
{
string invoice = InvoiceNumberFunc(sr);
// Use invoice
}
}
}
string InvoiceNumberFunc(TextReader reader)
{
string invoiceNumber;
try
{
invoiceNumber = reader.ReadLine();
}
catch (Exception exp)
{
Console.WriteLine("The process failed: {0}", exp.ToString());
}
return invoiceNumber;
}
You can't, since you create and dispose the stream reader in the function. Two ways come to mind:
You could store the stream reader in a member variable, or read all at once and store an array in a member variable.
Or you make it an iterator method by changing the return type to IEnumerable<string>, and changing the part in the using block to:
while ((invoiceNumber = sr.ReadLine()) != null) {
yield return invoiceNumber;
}
This way, you can call foreach on your invoiceNumberFunc.
You need to use the same StreamReader rather than creating a new one. Each time you create a new one and dispose of the old one you're starting right back at the start of the file.
Try passing the same StreamReader reference in or keeping a record of the position you are at in the stream and using Seek() on the base stream if necessary. I'd recommend the first of these personally.
You need to rework this, so that you're not creating the streamreader inside the method, but rather creating it at the class level, and just using it in the method, then disposing/closing the reader when you are done. Something like:
class MyClass
{
private StreamReader sr;
string invoiceNumberFunc()
{
if (sr == null)
sr = new StreamReader(path);
if (sr.EndOfStream) {
sr.Close();
sr = null;
return string.Empty;
}
try {
return sr.ReadLine();
}
catch(Exception exp) {
Console.WriteLine("Process failed {0}",exp.ToString());
return string.Empty;
}
}
}
In this case, it might also be a good idea to make your class IDisposable so you can verify that the StreamReader gets disposed, and also potentially make "initialize"/"close" routines, instead of doing the initialize and shutdown how I did here.
What you are looking for is the yield command:-
IEnumerable<string> GetInvoiceNumbers()
{
string path = #"C:\Users\sam\Documents\GCProg\testReadFile.txt";
using (StreamReader sr = new StreamReader(path))
{
while (!sr.EndOfStream)
{
yield return sr.ReadLine();
}
}
}
Now you can consume the return of this function with a simple for each:-
foreach(string invoiceNumber in GetInvoiceNumbers())
{
//Do Stuff with invoice number
}
Or get creative with LINQ.
An other way of doing this is to transform your function in an iterator block using the yield return statement
The only thing is to make sure you add a finaly clause to your try and remove the catch as the yield return cannot be used in a naked try / catch. So your code would become:
IEnumerable<String> invoiceNumberFunc()
{
string path = #"C:\Users\sam\Documents\GCProg\testReadFile.txt";
try
{
using ( System.IO.StreamReader sr = new System.IO.StreamReader( path ) )
{
String invoiceNumber;
while ( ( invoiceNumber = sr.ReadLine() ) != null )
{
yield return sr.ReadLine();
}
}
}
finally
{
}
}