我猜你要找的是“1.4 MB”而不是“1468006字节”?

我不认为在。net中有内置的方法来做到这一点。你只需要找出哪个单元是合适的，然后格式化它。

编辑:这里有一些示例代码来做到这一点:

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

所有溶液的混合:-)

    /// <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="fileSize">The numeric value to be converted.</param>
    /// <returns>The converted string.</returns>
    public static string FormatByteSize(double fileSize)
    {
        FileSizeUnit unit = FileSizeUnit.B;
        while (fileSize >= 1024 && unit < FileSizeUnit.YB)
        {
            fileSize = fileSize / 1024;
            unit++;
        }
        return string.Format("{0:0.##} {1}", fileSize, unit);
    }

    /// <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="fileInfo"></param>
    /// <returns>The converted string.</returns>
    public static string FormatByteSize(FileInfo fileInfo)
    {
        return FormatByteSize(fileInfo.Length);
    }
}

public enum FileSizeUnit : byte
{
    B,
    KB,
    MB,
    GB,
    TB,
    PB,
    EB,
    ZB,
    YB
}

下面是一个自动确定单位的简明答案。

public static string ToBytesCount(this long bytes)
{
    int unit = 1024;
    string unitStr = "B";
    if (bytes < unit)
    {
        return string.Format("{0} {1}", bytes, unitStr);
    }
    int exp = (int)(Math.Log(bytes) / Math.Log(unit));
    return string.Format("{0:##.##} {1}{2}", bytes / Math.Pow(unit, exp), "KMGTPEZY"[exp - 1], unitStr);
}

“b”代表bit，“b”代表Byte，“KMGTPEZY”分别代表kilo, mega, giga, tera, peta, exa, zetta和yotta

可以将ISO/IEC80000纳入考虑范围:

public static string ToBytesCount(this long bytes, bool isISO = true)
{
    int unit = isISO ? 1024 : 1000;
    string unitStr = "B";
    if (bytes < unit)
    {
        return string.Format("{0} {1}", bytes, unitStr);
    }
    int exp = (int)(Math.Log(bytes) / Math.Log(unit));
    return string.Format("{0:##.##} {1}{2}{3}", bytes / Math.Pow(unit, exp), "KMGTPEZY"[exp - 1], isISO ? "i" : "", unitStr);
}

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]);

另一种皮肤的方法，没有任何类型的循环和负大小支持(对文件大小增量有意义):

public static class Format
{
    static string[] sizeSuffixes = {
        "B", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB" };

    public static string ByteSize(long size)
    {
        Debug.Assert(sizeSuffixes.Length > 0);

        const string formatTemplate = "{0}{1:0.#} {2}";

        if (size == 0)
        {
            return string.Format(formatTemplate, null, 0, sizeSuffixes[0]);
        }

        var absSize = Math.Abs((double)size);
        var fpPower = Math.Log(absSize, 1000);
        var intPower = (int)fpPower;
        var iUnit = intPower >= sizeSuffixes.Length
            ? sizeSuffixes.Length - 1
            : intPower;
        var normSize = absSize / Math.Pow(1000, iUnit);

        return string.Format(
            formatTemplate,
            size < 0 ? "-" : null, normSize, sizeSuffixes[iUnit]);
    }
}

下面是测试套件:

[TestFixture] public class ByteSize
{
    [TestCase(0, Result="0 B")]
    [TestCase(1, Result = "1 B")]
    [TestCase(1000, Result = "1 KB")]
    [TestCase(1500000, Result = "1.5 MB")]
    [TestCase(-1000, Result = "-1 KB")]
    [TestCase(int.MaxValue, Result = "2.1 GB")]
    [TestCase(int.MinValue, Result = "-2.1 GB")]
    [TestCase(long.MaxValue, Result = "9.2 EB")]
    [TestCase(long.MinValue, Result = "-9.2 EB")]
    public string Format_byte_size(long size)
    {
        return Format.ByteSize(size);
    }
}

有一个开源项目可以做到这一点，甚至更多。

7.Bits().ToString();         // 7 b
8.Bits().ToString();         // 1 B
(.5).Kilobytes().Humanize();   // 512 B
(1000).Kilobytes().ToString(); // 1000 KB
(1024).Kilobytes().Humanize(); // 1 MB
(.5).Gigabytes().Humanize();   // 512 MB
(1024).Gigabytes().ToString(); // 1 TB

http://humanizr.net/#bytesize

https://github.com/MehdiK/Humanizer