How Do I Read a File As an Array of Bytes in C#
By
Steve on
Friday, February 16, 2007
Updated
Friday, April 22, 2016
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4 times today.)
.NET provides a lot of great tools for reading and writing files, lots of stream classes. If you're like me, I kind of find dealing with streams a pain. If I want to read a file I should only have to say "ReadFile" and the content should be there the way I want.
As a result, I tend to write lots of helper methods that hide the stream manipulations so I don't have to remember them. Here's one that will read any file as an array of bytes. I've found this useful with both binary and text files when I didn't have to analyze the data inside--such as a simple file transfer.
public static byte[] GetBytesFromFile(string fullFilePath)
{
// this method is limited to 2^32 byte files (4.2 GB)
FileStream fs = File.OpenRead(fullFilePath);
try
{
byte[] bytes = new byte[fs.Length];
fs.Read(bytes, 0, Convert.ToInt32(fs.Length));
fs.Close();
return bytes;
}
finally
{
fs.Close();
}
}
Update
The above is still a good way to read a file using a FileStream object, but a few years on and this functionality is now baked into the .NET framework.
byte[] bytes = File.ReadAllBytes("c:\folder\myfile.ext");