我如何获得一个人类可读的文件大小字节缩写使用。net ?
例子: 输入7,326,629,显示6.98 MB
我如何获得一个人类可读的文件大小字节缩写使用。net ?
例子: 输入7,326,629,显示6.98 MB
当前回答
下面是一个Log10的方法:
using System;
class Program {
static string NumberFormat(double n) {
var n2 = (int)Math.Log10(n) / 3;
var n3 = n / Math.Pow(1e3, n2);
return String.Format("{0:f3}", n3) + new[]{"", " k", " M", " G"}[n2];
}
static void Main() {
var s = NumberFormat(9012345678);
Console.WriteLine(s == "9.012 G");
}
}
https://learn.microsoft.com/dotnet/api/system.math.log10
其他回答
下面是@ deepe1的BigInteger版本的答案,它绕过了long的大小限制(因此支持yottabyte和理论上的任何后面的限制):
public static string ToBytesString(this BigInteger byteCount, string format = "N3")
{
string[] suf = { "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "YiB" };
if (byteCount.IsZero)
{
return $"{0.0.ToString(format)} {suf[0]}";
}
var abs = BigInteger.Abs(byteCount);
var place = Convert.ToInt32(Math.Floor(BigInteger.Log(abs, 1024)));
var pow = Math.Pow(1024, place);
// since we need to do this with integer math, get the quotient and remainder
var quotient = BigInteger.DivRem(abs, new BigInteger(pow), out var remainder);
// convert the remainder to a ratio and add both back together as doubles
var num = byteCount.Sign * (Math.Floor((double)quotient) + ((double)remainder / pow));
return $"{num.ToString(format)} {suf[place]}";
}
这里没有什么东西完全符合我的需要,我根据这个线程制作了我自己的,所以这里是我的长扩展,允许您根据标准选择格式要求。
绝对不是最快的,但很灵活。支持EB/EiB。
// <summary>
/// <paramref name="byteCount"/> The original size in bytes ( 8 bits )
/// <paramref name="notationFormat"/> is supported in the following ways:
/// [ 'B' / 'b' : Binary : Kilobyte (KB) is 1024 bytes, Megabyte (MB) is 1048576 bytes, etc ]
/// [ 'I' / 'i' : IEC: Kibibyte (KiB) is 1024 bytes, Mebibyte (MiB) is 1048576 bytes, etc ]
/// [ 'D' / 'd' : Decimal : Kilobyte (KB) is 1000 bytes, Megabyte (MB) is 1000000 bytes, etc ]
/// </summary>
public static string ToDataSizeString( this long byteCount, char notationFormat = 'b' )
{
char[] supportedFormatChars = { 'b', 'i', 'd' };
var lowerCaseNotationFormat = char.ToLowerInvariant( notationFormat );
// Stop shooting holes in my ship!
if ( !supportedFormatChars.Contains( lowerCaseNotationFormat ) )
{
throw new ArgumentException( $"notationFormat argument '{notationFormat}' not supported" );
}
long ebLimit = 1152921504606846976;
long pbLimit = 1125899906842624;
long tbLimit = 1099511627776;
long gbLimit = 1073741824;
long mbLimit = 1048576;
long kbLimit = 1024;
var ebSuffix = "EB";
var pbSuffix = "PB";
var tbSuffix = "TB";
var gbSuffix = "GB";
var mbSuffix = "MB";
var kbSuffix = "KB";
var bSuffix = " B";
switch ( lowerCaseNotationFormat )
{
case 'b':
// Sweet as
break;
case 'i':
// Limits stay the same, suffixes need changed
ebSuffix = "EiB";
pbSuffix = "PiB";
tbSuffix = "TiB";
gbSuffix = "GiB";
mbSuffix = "MiB";
kbSuffix = "KiB";
bSuffix = " B";
break;
case 'd':
// Suffixes stay the same, limits need changed
ebLimit = 1000000000000000000;
pbLimit = 1000000000000000;
tbLimit = 1000000000000;
gbLimit = 1000000000;
mbLimit = 1000000;
kbLimit = 1000;
break;
default:
// Should have already Excepted, but hey whatever
throw new ArgumentException( $"notationFormat argument '{notationFormat}' not supported" );
}
string fileSizeText;
// Exa/Exbi sized
if ( byteCount >= ebLimit )
{
fileSizeText = $"{( (double)byteCount / ebLimit ):N1} {ebSuffix}";
}
// Peta/Pebi sized
else if ( byteCount >= pbLimit )
{
fileSizeText = $"{( (double)byteCount / pbLimit ):N1} {pbSuffix}";
}
// Tera/Tebi sized
else if ( byteCount >= tbLimit )
{
fileSizeText = $"{( (double)byteCount / tbLimit ):N1} {tbSuffix}";
}
// Giga/Gibi sized
else if ( byteCount >= gbLimit )
{
fileSizeText = $"{( (double)byteCount / gbLimit ):N1} {gbSuffix}";
}
// Mega/Mibi sized
else if ( byteCount >= mbLimit )
{
fileSizeText = $"{( (double)byteCount / mbLimit ):N1} {mbSuffix}";
}
// Kilo/Kibi sized
else if ( byteCount >= kbLimit )
{
fileSizeText = $"{( (double)byteCount / kbLimit ):N1} {kbSuffix}";
}
// Byte sized
else
{
fileSizeText = $"{byteCount} {bSuffix}";
}
return fileSizeText;
}
这可能不是最有效或最优化的方法,但如果您不熟悉对数数学,它更容易阅读,并且对于大多数情况来说应该足够快。
string[] sizes = { "B", "KB", "MB", "GB", "TB" };
double len = new FileInfo(filename).Length;
int order = 0;
while (len >= 1024 && order < sizes.Length - 1) {
order++;
len = len/1024;
}
// Adjust the format string to your preferences. For example "{0:0.#}{1}" would
// show a single decimal place, and no space.
string result = String.Format("{0:0.##} {1}", len, sizes[order]);
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
我使用下面的Long扩展方法将其转换为人类可读的大小字符串。这个方法是在Stack Overflow上发布的相同问题的Java解决方案的c#实现。
/// <summary>
/// Convert a byte count into a human readable size string.
/// </summary>
/// <param name="bytes">The byte count.</param>
/// <param name="si">Whether or not to use SI units.</param>
/// <returns>A human readable size string.</returns>
public static string ToHumanReadableByteCount(
this long bytes
, bool si
)
{
var unit = si
? 1000
: 1024;
if (bytes < unit)
{
return $"{bytes} B";
}
var exp = (int) (Math.Log(bytes) / Math.Log(unit));
return $"{bytes / Math.Pow(unit, exp):F2} " +
$"{(si ? "kMGTPE" : "KMGTPE")[exp - 1] + (si ? string.Empty : "i")}B";
}