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
比如@NET3的解决方案。使用shift而不是除法来测试字节的范围,因为除法占用更多的CPU成本。
private static readonly string[] UNITS = new string[] { "B", "KB", "MB", "GB", "TB", "PB", "EB" };
public static string FormatSize(ulong bytes)
{
int c = 0;
for (c = 0; c < UNITS.Length; c++)
{
ulong m = (ulong)1 << ((c + 1) * 10);
if (bytes < m)
break;
}
double n = bytes / (double)((ulong)1 << (c * 10));
return string.Format("{0:0.##} {1}", n, UNITS[c]);
}
其他回答
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)。
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
}
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]);
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
为了获得人类可读的字符串,就像用户在Windows环境中习惯的那样,你应该使用StrFormatByteSize():
using System.Runtime.InteropServices;
...
private long mFileSize;
[DllImport("Shlwapi.dll", CharSet = CharSet.Auto)]
public static extern int StrFormatByteSize(
long fileSize,
[MarshalAs(UnmanagedType.LPTStr)] StringBuilder buffer,
int bufferSize);
public string HumanReadableFileSize
{
get
{
var sb = new StringBuilder(20);
StrFormatByteSize(mFileSize, sb, 20);
return sb.ToString();
}
}
我在这里找到了这个: http://csharphelper.com/blog/2014/07/format-file-sizes-in-kb-mb-gb-and-so-forth-in-c/