How do I get a human-readable file size using .NET?

Question

I assume this was already answered somewhere on SO, but I must be looking for the wrong keywords. I'll gladly remove this question if its a dup.

If not, let's answer the question here.

Example: Take input 7,326,629 and display 6.98 MB

Answer 1

int size = new FileInfo( filePath ).Length / 1024;
string humanKBSize = string.Format( "{0} KB", size );
string humanMBSize = string.Format( "{0} MB", size / 1024 );
string humanGBSize = string.Format( "{0} GB", size / 1024 / 1024 );

Answer 2

I assume you're looking for "1.4 MB" instead of "1468006 bytes"?

I don't think there is a built-in way to do that in .NET. You'll need to just figure out which unit is appropriate, and format it.

Edit: Here's some sample code to do just that:

http://www.codeproject.com/KB/cpp/formatsize.aspx

Answer 3

I did not test this, but it should give you an idea of how to do it.

string[] sizes = { "B", "KB", "MB", "GB" };
double len = new FileInfo(filename).Length;
int order = 0;
while (len >= 1024 && order + 1 < sizes.Length) {
    order++;
    len = len/1024;
}
string result = String.Format("{0:0.##} {1}", len, sizes[order]);

Answer 4

string[] suffixes = { "B", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB" };
int s = 0;
long size = fileInfo.Length;

while (size >= 1024)
{
    s++;
    size /= 1024;
}

string humanReadable = String.Format("{0} {1}", size, suffixes[s]);

Answer 5

[DllImport ( "Shlwapi.dll", CharSet = CharSet.Auto )]
public static extern long StrFormatByteSize ( 
        long fileSize
        , [MarshalAs ( UnmanagedType.LPTStr )] StringBuilder buffer
        , int bufferSize );


/// <summary>
/// Converts a numeric value into a string that represents the number expressed as a size value in bytes, kilobytes, megabytes, or gigabytes, depending on the size.
/// </summary>
/// <param name="filelength">The numeric value to be converted.</param>
/// <returns>the converted string</returns>
public static string StrFormatByteSize (long filesize) {
     StringBuilder sb = new StringBuilder( 11 );
     StrFormatByteSize( filesize, sb, sb.Capacity );
     return sb.ToString();
}

From: http://www.pinvoke.net/default.aspx/shlwapi/StrFormatByteSize.html