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
如果你试图匹配Windows资源管理器的详细信息视图中显示的大小,这是你想要的代码:
[DllImport("shlwapi.dll", CharSet = CharSet.Unicode)]
private static extern long StrFormatKBSize(
long qdw,
[MarshalAs(UnmanagedType.LPTStr)] StringBuilder pszBuf,
int cchBuf);
public static string BytesToString(long byteCount)
{
var sb = new StringBuilder(32);
StrFormatKBSize(byteCount, sb, sb.Capacity);
return sb.ToString();
}
这不仅会与资源管理器完全匹配,而且还会为您提供翻译后的字符串,并匹配Windows版本的差异(例如在Win10中,K = 1000 vs.之前的版本K = 1024)。
其他回答
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
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
}
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 );
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
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]}";
}