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Hi,
I'm used to c++, and now, with c#, there's one thing that is annoying me:
I want to write text files to disk sequentially, so I dediced to use a StreamWriter. Well, first I create my StreamWriter
StreamWriter filewriter = new StreamWriter(DateTime.Now.ToString("yyyyMMddHHmmss"));
After using it, I close it
filewriter.Close();
and then, how can I open a new file with the same stream writer? Do I have to instance a new streamwriter again? I'm missing c++ filewriter.Open(DateTime.Now.ToString("yyyyMMddHHmmss"));
Thanks in advance.
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The stream writer works as a wrapper around a specific stream. When you close the stream writer it's disposed and not usable any more. To write another stream you create a new stream writer for that stream.
---
Year happy = new Year(2007);
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Ok, thank you for the information. So, now the question is: Is there a file stream oriented object more specialized in reusability?
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jarellan wrote: Is there a file stream oriented object more specialized in reusability?
It has been several years since I last used C++, but I don't think you reused the file resources in C++ either. The when you re-opened a stream you would most likely get a different file handle internally anyway. It was just the class's public interface that made it appear otherwise.
Also, when you Dispose an object in C# (or close a stream) it tells the garbage collector to suppress the finaliser (the .NET equivalent of a destructor). The Finaliser is a safety mechanism in case the managed .NET object goes out of scope while holding onto unmanaged resources, like a file handle. Because the Dispose method and Close method cleans up the unmanaged resources the object can be flagged as not needing to run the finalizer any more. This speeds up garbage collection.
It is possible for an object to call ReRegisterForFinalizer if it needs to, but the documentation does list this very important caveat "Calling the ReRegisterForFinalize method does not guarantee that the garbage collector will call an object's finalizer." [my emphasis]. Without the gurarantee the application could leak memory all over the place if the developer of the client code forgot to call Dispose or Close, or was not disciplined into ensuring that it was called.
I hope this helps.
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I thought c++ fstream open-close doesn't reallocate memory resources...
Anyway, everything I found on the Internet was about StreamWriter, so I think it's the best option...
Thankyou very much.
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jarellan wrote: Is there a file stream oriented object more specialized in reusability?
No, there isn't.
Don't worry about creating a few objects, the memory management in .NET is built to handle that efficiently. Short lived objects are easily handled by the garbage collector, it's actually the objects that you hold on to a bit longer that gets more expensive.
As memory allocation is more expensive in C++, the classes are built for reusability. In .NET it's generally more efficient to just create a new object, so the classes are more often built to be used just once.
---
Year happy = new Year(2007);
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I have to change my mind... Always thinking about memory saving...
Thankyou ;o)
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Hi, I am wondering how can i write only 80 characters to a File.txt file from a string variable line which has more than 100 characters. But rest of the characters should start on a new line in the same file from 81-100. How can i do.
String line=;
FileStream fs = new FileStream("C:\\File.txt", FileMode.Create);
StreamWriter sw = new StreamWriter(fs);
sw.WriteLine(line);
Thanks
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I'll give you a hint: String.ToCharArray
You should be able to complete your homework now.
only two letters away from being an asset
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String line= yourestring.Insert(80,System.Environment.NewLine);
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Use the Substring method to get different parts of a string:
sw.WriteLine(line.Substring(0, 80));<br />
sw.Write(line.Substring(80));
-- modified at 19:16 Wednesday 10th January, 2007
Corrected line,Substring to line.Substring
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Year happy = new Year(2007);
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substring can give string of 0-80 characters but if i want to to get more strings from 91-100 then it wouldn't work because the second parameter for substring ask how many character you want so i can't even have string.substring(80,string.length).
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umm....Chief, even with the logic that you provided, you could get the 'number of characters that you wanted' by providing
string.substring(80, (string.length-80));
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Look at the code that I gave you. What do you think that the second line does?
If it's not obvious to you, look up the documentation for the Substring method, especially the overload that takes a single parameter.
---
Year happy = new Year(2007);
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...are you saying that to me?
if(you_are)
{
ummm....dude: wasn't replying to you. I was replying to op's post of :
substring can give string of 0-80 characters but if i want to to get more strings from 91-100 then it wouldn't work because the second parameter for substring ask how many character you want so i can't even have string.substring(80,string.length).
..and if you look carefully at the context of my message, you will notice this.
}
else
{
make sure that you reply in the correct context. The way you replied implies that it is tagged to my response.
}
(Nyquist Rate || ! Nyquist Rate)
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Alaric_ wrote: ...are you saying that to me?
Of course not. I replied to netJP12L.
make sure that you reply in the correct context.
I did. I have done this 5000 times before, I think that I have got the hang of it by now... 
The way you replied implies that it is tagged to my response.
No, it doesn't. It's just you who aren't familiar with how the tree structure of the thread is displayed. Perhaps it's the lack of the actual tree branches that is confusing?
---
Year happy = new Year(2007);
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...no. The thread spanned 2 pages and the posts in question were on a separate page. Whenever I read your message, I could have sworn it was nested 3 deep
(Nyquist Rate || ! Nyquist Rate)
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Thanks guys i have done it with all of your help. I finally figure out what i really wanted to do.
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Hi all,
My boss has just had a DVMR-N16CD installed along with 6 camera's.
The software viewer (DVR Remote Viewer) connects to the DMVR via port 50000 but when I telnet to that port I get nothing, I have also tried using a Socket connection to connect but receive nothing.
I then used ethereal and watched the communications between my computer and the DMVR using the DVR Remote Viewer and all is fine. I try to replicate the TCP Negotiation but I still get no response.
Anyone had any experience on this?
Regards
Gav
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I'm glad someone replied.
It's not so much an C# issue but I would like to use C# to access my DVR Recorder.
I've found some handshakes but they don't seem to respond.
Any idea's?
Gav
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figure out what's different between the working packets you've captured and disassembled and the packets your nonworking app is generating. Change your app to send the correct packets.
Sorry I can't be more helpful but unless your vendor has a forum for this sort of task I doubt you'll be able to find anyone whose done what you're trying to do.
--
Rules of thumb should not be taken for the whole hand.
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I've managed this before with Telnet as Ethereal has support to decode Telnet Neg commands but I cannot find anything to suggest what is being used apart from TCP.
If I use a Stream and TcpClient I can connect but I do not receive anything even if I send the packet that is being sent via the software.
I've tried looking all over, it seems that the manufacture can not be found anywhere.
Gav
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Is it just me or are there an increasing number of questions being asked that are answered in the documentation on MSDN? I know that MSDN can be a bit vague sometimes on the more esoteric topics, but these are increadibly basic questions that are actually quite well documented.
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Colin Angus Mackay wrote: Is it just me or are there an increasing number of questions being asked that are answered in the documentation on MSDN? I know that MSDN can be a bit vague sometimes on the more esoteric topics, but these are increadibly basic questions that are actually quite well documented.
Must be term time again.
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