问题
How can I create a .csv file implicitly/automatically by using the correct method, add text to that file existing in memory and then convert to in memory data to a byte array?
string path = @"C:\test.txt";
File.WriteAllLines(path, GetLines());
byte[] bytes = System.IO.File.ReadAllBytes(path);
With that approach I create a file always (good), write into it (good) then close it (bad) then open the file again from a path and read it from the hard disc (bad)
How can I improve that?
UPDATE
One nearly good approach would be:
using (var fs = new FileStream(@"C:\test.csv", FileMode.Create, FileAccess.ReadWrite))
{
using (var memoryStream = new MemoryStream())
{
fs.CopyTo(memoryStream );
return memoryStream .ToArray();
}
}
but I am not able to write text into that filestream... just bytes...
UPDATE 2
using (var fs = File.Create(@"C:\temp\test.csv"))
{
using (var sw = new StreamWriter(fs, Encoding.Default))
{
using (var ms = new MemoryStream())
{
String message = "Message is the correct ääüö Pi(\u03a0), and Sigma (\u03a3).";
sw.Write(message);
sw.Flush();
fs.CopyTo(ms);
return ms.ToArray();
}
}
}
The string message is not persisted to the test.csv file. Anyone knows why?
回答1:
Write text into Memory Stream.
byte[] bytes = null;
using (var ms = new MemoryStream())
{
TextWriter tw = new StreamWriter(ms);
tw.Write("blabla");
tw.Flush();
ms.Position = 0;
bytes = ms.ToArray();
//or save to disk using FileStream (fs)
ms.WriteTo(fs);
}
UPDATE
Use file stream Directly
using (var fs = new FileStream(@"C:\sh\test.csv", FileMode.Create, FileAccess.ReadWrite))
{
TextWriter tw = new StreamWriter(fs);
tw.Write("blabla");
tw.Flush();
}
回答2:
You can get a byte array from a string using encoding:
Encoding.ASCII.GetBytes(aString);
Or
Encoding.UTF8.GetBytes(aString);
But I don't know why you would want a csv as bytes. You could load the entire file to a string, add to it and then save it:
string content;
using (var reader = new StreamReader(filename))
{
content = reader.ReadToEnd();
}
content += "x,y,z";
using (var writer = new StreamWriter(filename))
{
writer.Write(content);
}
Update: Create a csv in memory and pass back as bytes:
var stringBuilder = new StringBuilder();
foreach(var line in GetLines())
{
stringBuilder.AppendLine(log);
}
return Encoding.ASCII.GetBytes(stringBuilder.ToString());
来源:https://stackoverflow.com/questions/36661211/create-and-write-to-a-text-file-inmemory-and-convert-to-byte-array-in-one-go