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
请求函数的测试和显著优化版本发布在这里:
c#人类可读文件大小-优化的函数
源代码:
// Returns the human-readable file size for an arbitrary, 64-bit file size
// The default format is "0.### XB", e.g. "4.2 KB" or "1.434 GB"
public string GetBytesReadable(long i)
{
// Get absolute value
long absolute_i = (i < 0 ? -i : i);
// Determine the suffix and readable value
string suffix;
double readable;
if (absolute_i >= 0x1000000000000000) // Exabyte
{
suffix = "EB";
readable = (i >> 50);
}
else if (absolute_i >= 0x4000000000000) // Petabyte
{
suffix = "PB";
readable = (i >> 40);
}
else if (absolute_i >= 0x10000000000) // Terabyte
{
suffix = "TB";
readable = (i >> 30);
}
else if (absolute_i >= 0x40000000) // Gigabyte
{
suffix = "GB";
readable = (i >> 20);
}
else if (absolute_i >= 0x100000) // Megabyte
{
suffix = "MB";
readable = (i >> 10);
}
else if (absolute_i >= 0x400) // Kilobyte
{
suffix = "KB";
readable = i;
}
else
{
return i.ToString("0 B"); // Byte
}
// Divide by 1024 to get fractional value
readable = (readable / 1024);
// Return formatted number with suffix
return readable.ToString("0.### ") + suffix;
}
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]}";
}
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);
}
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";
}
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 );
请求函数的测试和显著优化版本发布在这里:
c#人类可读文件大小-优化的函数
源代码:
// Returns the human-readable file size for an arbitrary, 64-bit file size
// The default format is "0.### XB", e.g. "4.2 KB" or "1.434 GB"
public string GetBytesReadable(long i)
{
// Get absolute value
long absolute_i = (i < 0 ? -i : i);
// Determine the suffix and readable value
string suffix;
double readable;
if (absolute_i >= 0x1000000000000000) // Exabyte
{
suffix = "EB";
readable = (i >> 50);
}
else if (absolute_i >= 0x4000000000000) // Petabyte
{
suffix = "PB";
readable = (i >> 40);
}
else if (absolute_i >= 0x10000000000) // Terabyte
{
suffix = "TB";
readable = (i >> 30);
}
else if (absolute_i >= 0x40000000) // Gigabyte
{
suffix = "GB";
readable = (i >> 20);
}
else if (absolute_i >= 0x100000) // Megabyte
{
suffix = "MB";
readable = (i >> 10);
}
else if (absolute_i >= 0x400) // Kilobyte
{
suffix = "KB";
readable = i;
}
else
{
return i.ToString("0 B"); // Byte
}
// Divide by 1024 to get fractional value
readable = (readable / 1024);
// Return formatted number with suffix
return readable.ToString("0.### ") + suffix;
}