I am reading a text file through a web service. I am getting the data in chunks of byte[] data and reassembling it into a MemoryStream. Now I am trying to figure out how to display the text data in a textarea. Any recommendations on how to do this, I'm stuck?
Update
Here is the final solution that returns the contents of the text file as a string which is then displayed in the textarea.
public string DownloadFile(string filenamepath)
{
int offset = 0;
int chunkSize = 16000;
string filecontents = string.Empty;
using (var wsc = new WebServiceClient())
{
using (var fs = new MemoryStream())
{
while (true)
{
var buffer = wsc.DownloadFile(filenamepath, offset, chunkSize);
int read = buffer.Length;
if (read <= 0)
break;
fs.Seek(offset, SeekOrigin.Begin);
fs.Write(buffer, 0, read);
offset += read;
}
using (var reader = new StreamReader(fs))
{
reader.BaseStream.Seek(0, SeekOrigin.Begin);
filecontents = reader.ReadToEnd();
}
}
}
return filecontents;
}
Wrap a StreamReader around that MemoryStream and call the reader's ReadToEnd() method.
Make sure to set the reader's encoding accordingly.
Use:
MemoryStream stream = ... //Your memory stream here
using (var reader = new StreamReader(stream))
{
textArea.Text = reader.ReadToEnd();
}
Related
I have some numbers under each oterh, like this:
71004
71006
71008
71026
71028
They are standing in a text file. And I want to read the textfile and then modify the textfile, so it becomes:
71004|71006|71008|71026|71028|
I try it like this:
class Program
{
static void Main(string[] args)
{
string file1 = #"D:\Docs\ImportDataInNAV\ImportVendorNumbers.txt";
using (StreamReader stream = File.OpenText(file1))
{
string s = String.Empty;
while ((s = stream.ReadLine()) != null)
{
foreach (var line in s)
{
Console.WriteLine(line);
}
}
}
}
}
Thank you
I try it like this:
using (FileStream stream = File.OpenRead(#"D:\\Docs\\ImportDataInNAV\\ImportVendorNumbers.txt"))
using (FileStream writeStream = File.OpenWrite("D:\\file2.txt"))
{
var output = string.Join("|", File.ReadLines(writeStream));
BinaryReader reader = new BinaryReader(stream);
BinaryWriter writer = new BinaryWriter(writeStream);
// create a buffer to hold the bytes
byte[] buffer = new Byte[1024];
int bytesRead;
// while the read method returns bytes
// keep writing them to the output stream
while ((bytesRead = stream.Read(buffer, 0, 1024)) > 0)
{
//writeStream.Write(buffer, 0, bytesRead) ;
File.WriteAllText(filepath, output);
}
}
I want to read the textfile and then modify the textfile, so it
becomes:
71004|71006|71008|71026|71028|
Use string.Join to form | delimited string.
var output -string.Join("|",File.ReadLines(filepath));
File.WriteAllText(filepath, output);
Not sure | at the end is intentional, if it is desired output concat | at the end to output before writing.
how about Run your code like
yourprograme.exe > outputfile.txt
I have a program that takes in mp3 data in a byte array. It has to convert that mp3 data into wav format and store it in a byte data. I am trying to use NAudio for this purpose. I am using the following code for this purpose.
Stream inputStream = ...;
Stream outputStream = ...;
using (WaveStream waveStream = WaveFormatConversionStream.CreatePcmStream(new Mp3FileReader(inputStream)))
using (WaveFileWriter waveFileWriter = new WaveFileWriter(outputStream, waveStream.WaveFormat))
{
byte[] bytes = new byte[waveStream.Length];
waveStream.Read(bytes, 0, waveStream.Length);
waveFileWriter.WriteData(bytes, 0, bytes.Length);
waveFileWriter.Flush();
}
When I run the above code, all I receive is 0 in the byte array. But if use WaveFileWriter to write the data directly to a file, the file receives the correct data. Any reasons?
Give this a try:
using (WaveStream waveStream = WaveFormatConversionStream.CreatePcmStream(new Mp3FileReader(inputStream)))
using (WaveFileWriter waveFileWriter = new WaveFileWriter(outputStream, waveStream.WaveFormat))
{
byte[] bytes = new byte[waveStream.Length];
waveStream.Position = 0;
waveStream.Read(bytes, 0, waveStream.Length);
waveFileWriter.WriteData(bytes, 0, bytes.Length);
waveFileWriter.Flush();
}
If you are writing to a MemoryStream, you need to be aware that WaveFileWriter will dispose that MemoryStream after you dispose the WaveFileWriter.
Here's a workaround using the IgnoreDisposeStream. (Also note that WaveFormatConversionStream.CreatePcmStream is unnecessary - Mp3FileReader already returns PCM from Read). I also prefer to read in smaller chunks that trying to pass through the whole file.
var path = #"mytestFile.mp3";
var mp3ByteArray = File.ReadAllBytes(path);
var outputStream = new MemoryStream();
using (var mp3Stream = new MemoryStream(mp3ByteArray))
using (var reader = new Mp3FileReader(mp3Stream))
using (var waveFileWriter = new WaveFileWriter(new IgnoreDisposeStream(outputStream),
reader.WaveFormat))
{
byte[] buffer = new byte[reader.WaveFormat.AverageBytesPerSecond];
int read;
while((read = reader.Read(buffer,0, buffer.Length)) > 0)
{
waveFileWriter.Write(buffer, 0, read);
}
}
// outputStream has not yet been disposed so we can get the byte array from it
var wavBytes = outputStream.GetBuffer();
// or we could play it like this
outputStream.Position = 0;
using (var player = new WaveOutEvent())
using (var reader = new WaveFileReader(outputStream))
{
player.Init(reader);
player.Play();
while(player.PlaybackState != PlaybackState.Stopped)
{
Thread.Sleep(1000);
}
}
i am using: `private void get_stocks_data()
{
byte[] result;
byte[] buffer = new byte[4096];
WebRequest wr = WebRequest.Create("http://www.tase.co.il/TASE/Pages/ExcelExport.aspx?sn=he-IL_ds&enumTblType=AllSecurities&Columns=he-IL_Columns&Titles=he-IL_Titles&TblId=0&ExportType=1");
using (WebResponse response = wr.GetResponse())
{
using (Stream responseStream = response.GetResponseStream())
{
using (MemoryStream memoryStream = new MemoryStream())
{
int count = 0;
do
{
count = responseStream.Read(buffer, 0, buffer.Length);
memoryStream.Write(buffer, 0, count);
} while (count != 0);
result = memoryStream.ToArray();
write_data_to_excel(result);
}
}
}`
to download the excel file,
And this method to fill the file on my computer:
private void write_data_to_excel(byte[] input)
{
StreamWriter str = new StreamWriter("stockdata.xls");
for (int i = 0; input.Length > i; i++)
{
str.WriteLine(input[i].ToString());
}
str.Close();
}
The result is that i get a lot of numbers...
What am i doing wrong? the file i am downloadin is excel version 2003, on my computer i have 2007...
Thanks.
I would suggest that you use WebClient.DownloadFile() instead.
This is a higher level method that will abstract from creating the request manually, dealing with encoding, etc.
Problem is in your Write_data_to_excel function
as you are using StreamWriter.WriteLine method it needs string,
you are passing byte as string so your binary value say 10 will be now string 10
try FileStream f = File.OpenWrite("stockdata.xlsx");
f.Write(input,0,input.Length); this will work.
I know this question has been asked before on Stackoverflow, but could not find an explanation.
When I try to read a string from a compressed byte array I get an empty string on the first attempt, on the second I succed and get the string.
Code example:
public static string Decompress(byte[] gzBuffer)
{
if (gzBuffer == null)
return null;
using (var ms = new MemoryStream(gzBuffer))
{
using (var decompress = new GZipStream(ms, CompressionMode.Decompress))
{
using (var sr = new StreamReader(decompress, Encoding.UTF8))
{
string ret = sr.ReadToEnd();
// this is the extra check that is needed !?
if (ret == "")
ret = sr.ReadToEnd();
return ret;
}
}
}
}
All suggestions are appreciated.
- Victor Cassel
I found the bug. It was as Michael suggested in the compression routine. I missed to call Close() on the GZipStream.
public static byte[] Compress(string text)
{
if (string.IsNullOrEmpty(text))
return null;
byte[] raw = Encoding.UTF8.GetBytes(text);
using (var ms = new MemoryStream())
{
using (var compress = new GZipStream (ms, CompressionMode.Compress))
{
compress.Write(raw, 0, raw.Length);
compress.Close();
return ms.ToArray();
}
}
}
What happened was that the data seemed to get saved in a bad state that required two calls to ReadToEnd() in the decompression routine later on to extract the same data. Very odd!
try adding ms.Position = 0 before string ret = sr.ReadToEnd();
Where is gzBuffer coming from? Did you also write the code that is producing the compressed data?
Perhaps the buffer data you have is invalid or somehow incomplete, or perhaps it consists of multiple deflate streams concatenated together.
I hope this helps.
For ByteArray:
static byte[] CompressToByte(string data)
{
MemoryStream outstream = new MemoryStream();
GZipStream compressionStream =
new GZipStream(outstream, CompressionMode.Compress, true);
StreamWriter writer = new StreamWriter(compressionStream);
writer.Write(data);
writer.Close();
return StreamToByte(outstream);
}
static string Decompress(byte[] data)
{
MemoryStream instream = new MemoryStream(data);
GZipStream compressionStream =
new GZipStream(instream, CompressionMode.Decompress);
StreamReader reader = new StreamReader(compressionStream);
string outtext = reader.ReadToEnd();
reader.Close();
return outtext;
}
public static byte[] StreamToByte(Stream stream)
{
stream.Position = 0;
byte[] buffer = new byte[128];
using (MemoryStream ms = new MemoryStream())
{
while (true)
{
int read = stream.Read(buffer, 0, buffer.Length);
if (!(read > 0))
return ms.ToArray();
ms.Write(buffer, 0, read);
}
}
}
You can replace if(!(read > 0)) with if(read <= 0).
For some reason if(read <= 0) isn't displayed corret above.
For Stream:
static Stream CompressToStream(string data)
{
MemoryStream outstream = new MemoryStream();
GZipStream compressionStream =
new GZipStream(outstream, CompressionMode.Compress, true);
StreamWriter writer = new StreamWriter(compressionStream);
writer.Write(data);
writer.Close();
return outstream;
}
static string Decompress(Stream data)
{
data.Position = 0;
GZipStream compressionStream =
new GZipStream(data, CompressionMode.Decompress);
StreamReader reader = new StreamReader(compressionStream);
string outtext = reader.ReadToEnd();
reader.Close();
return outtext;
}
The MSDN Page on the function mentions the following:
If the current method throws an OutOfMemoryException, the reader's position in the underlying Stream object is advanced by the number of characters the method was able to read, but the characters already read into the internal ReadLine buffer are discarded. If you manipulate the position of the underlying stream after reading data into the buffer, the position of the underlying stream might not match the position of the internal buffer. To reset the internal buffer, call the DiscardBufferedData method; however, this method slows performance and should be called only when absolutely necessary.
Perhaps try calling DiscardBufferedData() before your ReadToEnd() and see what it does (I know you aren't getting the exception, but it's all I can think of...)?
I am trying to read an Http response stream twice via the following:
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
stream = response.GetResponseStream();
RssReader reader = new RssReader(stream);
do
{
element = reader.Read();
if (element is RssChannel)
{
feed.Channels.Add((RssChannel)element);
}
} while (element != null);
StreamReader sr = new StreamReader(stream);
feed._FeedRawData = sr.ReadToEnd();
However when the StreamReader code executes there is no data returned because the stream has now reached the end. I tried to reset the stream via stream.Position = 0 but this throws an exception (I think because the stream can't have its position changed manually).
Basically, I would like to parse the stream for XML and have access to the raw data (in string format).
Any ideas?
Copy it into a new MemoryStream first. Then you can re-read the MemoryStream as many times as you like:
Stream responseStream = CopyAndClose(resp.GetResponseStream());
// Do something with the stream
responseStream.Position = 0;
// Do something with the stream again
private static Stream CopyAndClose(Stream inputStream)
{
const int readSize = 256;
byte[] buffer = new byte[readSize];
MemoryStream ms = new MemoryStream();
int count = inputStream.Read(buffer, 0, readSize);
while (count > 0)
{
ms.Write(buffer, 0, count);
count = inputStream.Read(buffer, 0, readSize);
}
ms.Position = 0;
inputStream.Close();
return ms;
}
Copying the stream to a MemoryStream as suggested by Iain is the right approach. But since
.NET Framework 4 (released 2010) we have Stream.CopyTo. Example from the docs:
// Create the streams.
MemoryStream destination = new MemoryStream();
using (FileStream source = File.Open(#"c:\temp\data.dat",
FileMode.Open))
{
Console.WriteLine("Source length: {0}", source.Length.ToString());
// Copy source to destination.
source.CopyTo(destination);
}
Console.WriteLine("Destination length: {0}", destination.Length.ToString());
Afterwards you can read destination as many times as you like:
// re-set to beginning and convert stream to string
destination.Position = 0;
StreamReader streamReader = new StreamReader(destination);
string text = streamReader.ReadToEnd();
// re-set to beginning and read again
destination.Position = 0;
RssReader cssReader = new RssReader(destination);
(I have seen Endy's comment but since it is an appropriate, current answer, it should have its own answer entry.)
have you tried resetting the stream position?
if this does not work you can copy the stream to a MemoryStream and there you can reset the position (i.e. to 0) as often as you want.