Best way to read a large file into a byte array in C#?

c# .net bytearray binary-data
Tony_Henrich picture Tony_Henrich · Jan 8, 2010 · Viewed 513.2k times · Source

I have a web server which will read large binary files (several megabytes) into byte arrays. The server could be reading several files at the same time (different page requests), so I am looking for the most optimized way for doing this without taxing the CPU too much. Is the code below good enough?

public byte[] FileToByteArray(string fileName)
{
    byte[] buff = null;
    FileStream fs = new FileStream(fileName, 
                                   FileMode.Open, 
                                   FileAccess.Read);
    BinaryReader br = new BinaryReader(fs);
    long numBytes = new FileInfo(fileName).Length;
    buff = br.ReadBytes((int) numBytes);
    return buff;
}

Answer

Mehrdad Afshari picture Mehrdad Afshari · Jan 8, 2010

Simply replace the whole thing with:

return File.ReadAllBytes(fileName);

However, if you are concerned about the memory consumption, you should not read the whole file into memory all at once at all. You should do that in chunks.

Related questions

Int to byte array

I thought .net had some kind of easy conversion method to use for converting an int into a byte array? I did a quick search and all solutions are bit masking/shifting one byte at a time, like "the good …

Read More
Error" Parameter is not valid " while converting Bytes into Image

I am converting bytes into an image but I get an error Parameter is not valid I am pasting my code. Kindly check the code and suggested that was I am doing right or wrong. Image arr1 = byteArrayToImage(Bytess); This …

Read More
How do I convert an array of floats to a byte[] and back?

I have an array of Floats that need to be converted to a byte array and back to a float[]... can anyone help me do this correctly? I'm working with the bitConverter class and found myself stuck trying to append …

Read More