byte array out of memory in c# 2

Question

FileStream fs = File.OpenRead(fullFilePath);
try
{
    Console.WriteLine("Read file size is : " + fs.Length);
    byte[] bytes = new byte[fs.Length]; //// **error this line**
    fs.Read(bytes, 0, Convert.ToInt32(fs.Length));
    fs.Close();
    return bytes;
}
finally
{
    fs.Close();
}

read file size 2,885,760 KB. is error //

**Arithmetic operation resulted in an overflow.**

This doesn't make sense at all. Please put some more effort into improving your question. — Arian Motamedi, Jun 19 '13 at 05:16
http://stackoverflow.com/a/3944336/251311 PS: and please try to use google before you ask next time — zerkms, Jun 19 '13 at 05:17
Btw, why do you need to read multy-gigabyte files into the memory? — zerkms, Jun 19 '13 at 05:18

score 6 · Accepted Answer · edited May 23 '17 at 12:02

6

That file size is over 2GB. The problem is that new byte[OverTwoBillionAndSome] is exceeding the limits. If the length was under 2GB this error would not occur (although it might still be advisable to not read it entirely into memory).

Consider streaming the data instead.

edited May 23 '17 at 12:02

Community

1
1

answered Jun 19 '13 at 05:19

Paul

247
1
4

score 0 · Answer 2 · answered Jun 19 '13 at 05:18

byte[] bytes = new byte[fs.Length];

2,885,760 is more than 2GB. Are you sure you have enough space in your RAM? Most probably not, that's why you are getting out of memory exception.

Even if you have enough space in RAM, a normal 32 Bit cannot have that much memory allocated to it

score 0 · Answer 3 · edited May 23 '17 at 11:46

As Paul said, problem is the large size of file.

But with .NET Framework 4.5, you can use <gcAllowVeryLargeObjects> Element which supports you use objects that are greater than 2 GB in total size.

On 64-bit platforms, enables arrays that are greater than 2 gigabytes (GB) in total size.

You just need to change your configuration settings like;

<configuration>
  <runtime>
    <gcAllowVeryLargeObjects enabled="true" />
  </runtime>
</configuration>

byte array out of memory in c# 2

3 Answers3