Does .NET provide an easy way convert bytes to KB,

Question

Just wondering if .NET provides a clean way to do this:

int64 x = 1000000;
string y = null;
if (x / 1024 == 0) {
    y = x + " bytes";
}
else if (x / (1024 * 1024) == 0) {
    y = string.Format("{0:n1} KB", x / 1024f);
}

etc...

Answer 1

I would solve it using Extension methods, Math.Pow function and Enums:

public static class MyExtension
{
    public enum SizeUnits
    {
        Byte, KB, MB, GB, TB, PB, EB, ZB, YB
    }

    public static string ToSize(this Int64 value, SizeUnits unit)
    {
        return (value / (double)Math.Pow(1024, (Int64)unit)).ToString("0.00");
    }
}

and use it like:

string h = x.ToSize(MyExtension.SizeUnits.KB);

Answer 2

Checkout the ByteSize library. It's the System.TimeSpan for bytes!

It handles the conversion and formatting for you.

var maxFileSize = ByteSize.FromKiloBytes(10);
maxFileSize.Bytes;
maxFileSize.MegaBytes;
maxFileSize.GigaBytes;

It also does string representation and parsing.

// ToString
ByteSize.FromKiloBytes(1024).ToString(); // 1 MB
ByteSize.FromGigabytes(.5).ToString();   // 512 MB
ByteSize.FromGigabytes(1024).ToString(); // 1 TB

// Parsing
ByteSize.Parse("5b");
ByteSize.Parse("1.55B");

Answer 3

How about:

public void printMB(uint sizekB)   
{
    double sizeMB = (double) sizekB / 1024;
    Console.WriteLine("Size is " + sizeMB.ToString("0.00") + "MB");
}

E.g. call like

printMB(123456);

Will result in output

"Size is 120,56 MB"

Answer 4

I have combined some of the answers here into two methods that work great. The second method below will convert from a bytes string (like 1.5.1 GB) back to bytes (like 1621350140) as a long type value. I hope this is useful to others looking for a solution to convert bytes to a string and back into bytes.

public static string BytesAsString(float bytes)
{
    string[] suffix = { "B", "KB", "MB", "GB", "TB" };
    int i;
    double doubleBytes = 0;

    for (i = 0; (int)(bytes / 1024) > 0; i++, bytes /= 1024)
    {
        doubleBytes = bytes / 1024.0;
    }

    return string.Format("{0:0.00} {1}", doubleBytes, suffix[i]);
}

public static long StringAsBytes(string bytesString)
{
    if (string.IsNullOrEmpty(bytesString))
    {
        return 0;
    }

    const long OneKb = 1024;
    const long OneMb = OneKb * 1024;
    const long OneGb = OneMb * 1024;
    const long OneTb = OneGb * 1024;
    double returnValue;
    string suffix = string.Empty;

    if (bytesString.IndexOf(" ") > 0)
    {
        returnValue = float.Parse(bytesString.Substring(0, bytesString.IndexOf(" ")));
        suffix = bytesString.Substring(bytesString.IndexOf(" ") + 1).ToUpperInvariant();
    }
    else
    {
        returnValue = float.Parse(bytesString.Substring(0, bytesString.Length - 2));
        suffix = bytesString.ToUpperInvariant().Substring(bytesString.Length - 2);
    }

    switch (suffix)
    {
        case "KB":
            {
                returnValue *= OneKb;
                break;
            }

        case "MB":
            {
                returnValue *= OneMb;
                break;
            }

        case "GB":
            {
                returnValue *= OneGb;
                break;
            }

        case "TB":
            {
                returnValue *= OneTb;
                break;
            }

        default:
            {
                break;
            }
    }

    return Convert.ToInt64(returnValue);
}

Answer 5

Based on NeverHopeless's elegant solution:

private static readonly KeyValuePair<long, string>[] Thresholds = 
{
    // new KeyValuePair<long, string>(0, " Bytes"), // Don't devide by Zero!
    new KeyValuePair<long, string>(1, " Byte"),
    new KeyValuePair<long, string>(2, " Bytes"),
    new KeyValuePair<long, string>(1024, " KB"),
    new KeyValuePair<long, string>(1048576, " MB"), // Note: 1024 ^ 2 = 1026 (xor operator)
    new KeyValuePair<long, string>(1073741824, " GB"),
    new KeyValuePair<long, string>(1099511627776, " TB"),
    new KeyValuePair<long, string>(1125899906842620, " PB"),
    new KeyValuePair<long, string>(1152921504606850000, " EB"),

    // These don't fit into a int64
    // new KeyValuePair<long, string>(1180591620717410000000, " ZB"), 
    // new KeyValuePair<long, string>(1208925819614630000000000, " YB") 
};

/// <summary>
/// Returns x Bytes, kB, Mb, etc... 
/// </summary>
public static string ToByteSize(this long value)
{
    if (value == 0) return "0 Bytes"; // zero is plural
    for (int t = Thresholds.Length - 1; t > 0; t--)
        if (value >= Thresholds[t].Key) return ((double)value / Thresholds[t].Key).ToString("0.00") + Thresholds[t].Value;
    return "-" + ToByteSize(-value); // negative bytes (common case optimised to the end of this routine)
}

Maybe there are excessive comments, but I tend to leave them to prevent myself from making the same mistakes over on future visits...

Answer 6

The short version of the most voted answer has problems with TB values.

I adjusted it appropriately to handle also tb values and still without a loop and also added a little error checking for negative values. Here's my solution:

static readonly string[] SizeSuffixes = { "bytes", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB" };
static string SizeSuffix(long value, int decimalPlaces = 0)
{
    if (value < 0)
    {
        throw new ArgumentException("Bytes should not be negative", "value");
    }
    var mag = (int)Math.Max(0, Math.Log(value, 1024));
    var adjustedSize = Math.Round(value / Math.Pow(1024, mag), decimalPlaces);
    return String.Format("{0} {1}", adjustedSize, SizeSuffixes[mag]);
}