我正在重构一些旧代码并遇到以下代码行将字节转换为GB。
decimal GB = KB / 1024 / 1024 / 1024;
有没有更好的方法来重构以下代码？
更新
我的意思是说千兆字节的字节数。我提供了错误的信息。
答案 0 :(得分：89)
我在这里开发了这种方法，可以达到TB。
private static string FormatBytes(long bytes)
{
string[] Suffix = { "B", "KB", "MB", "GB", "TB" };
int i;
double dblSByte = bytes;
for (i = 0; i < Suffix.Length && bytes >= 1024; i++, bytes /= 1024)
{
dblSByte = bytes / 1024.0;
}
return String.Format("{0:0.##} {1}", dblSByte, Suffix[i]);
}
答案 1 :(得分：18)
如果精确度不重要，请使用double：
double gb = kb / 1048576D
在这里同意Pavel - 没有必要重构这段代码......事实上，如果这是你的代码库中最大的问题，我想你可能会坐在最好的软件上。
答案 2 :(得分：7)
原始代码简洁，易于阅读，并且具有合理的变量名称，自我记录;我不会改变它。
如果绝对必须重构，可以在数字类型上创建一组扩展方法：
public static double BytesToKilobytes(this Int32 bytes)
{
return bytes / 1024d;
}
public static double BytesToMegabytes(this Int32 bytes)
{
return bytes / 1024d / 1024d;
}
public static double KilobytesToBytes(this double kilobytes)
{
return kilobytes * 1024d;
}
//You can then do something like:
double filesize = 32.5d;
double bytes = filesize.KilobytesToBytes();
但是，除非你的代码几乎没有做任何事情，只能将字节转换为千字节等，所有这一切真的会让Intellisense陷入混乱，无法获得真正的收益。
答案 3 :(得分：4)
/// <summary>
/// Function to convert the given bytes to either Kilobyte, Megabyte, or Gigabyte
/// </summary>
/// <param name="bytes">Double -> Total bytes to be converted</param>
/// <param name="type">String -> Type of conversion to perform</param>
/// <returns>Int32 -> Converted bytes</returns>
/// <remarks></remarks>
public static double ConvertSize(double bytes, string type)
{
try
{
const int CONVERSION_VALUE = 1024;
//determine what conversion they want
switch (type)
{
case "BY":
//convert to bytes (default)
return bytes;
case "KB":
//convert to kilobytes
return (bytes / CONVERSION_VALUE);
case "MB":
//convert to megabytes
return (bytes / CalculateSquare(CONVERSION_VALUE));
case "GB":
//convert to gigabytes
return (bytes / CalculateCube(CONVERSION_VALUE));
default:
//default
return bytes;
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
return 0;
}
}
/// <summary>
/// Function to calculate the square of the provided number
/// </summary>
/// <param name="number">Int32 -> Number to be squared</param>
/// <returns>Double -> THe provided number squared</returns>
/// <remarks></remarks>
public static double CalculateSquare(Int32 number)
{
return Math.Pow(number, 2);
}
/// <summary>
/// Function to calculate the cube of the provided number
/// </summary>
/// <param name="number">Int32 -> Number to be cubed</param>
/// <returns>Double -> THe provided number cubed</returns>
/// <remarks></remarks>
public static double CalculateCube(Int32 number)
{
return Math.Pow(number, 3);
}
//Sample Useage
String Size = "File is " + ConvertSize(250222,"MB") + " Megabytes in size"
答案 4 :(得分：2)
就我个人而言，我会这样写：decimal GB = KB / (1024 * 1024);但是实际上没有必要重写代码。
答案 5 :(得分：2)
嗯，这个公式是错误的（一千兆字节只有一百万字节，而不是十亿字节），但除此之外，它没关系。任何习惯使用这些数字的人都会知道这意味着什么。
我要注意的一件事（我不知道这是否是C＃的问题）是如果x/1024/1024不是x，编译器可能无法优化kiloBytes/gigaBytes基本类型。使用C和整数，编译器很容易将其转换为“快速移位 - 右移20位”指令。
如果decimal是类而不是基本类型，则编译器可能必须执行两次除法运算。这对速度是否有任何实际影响（甚至是否真的发生）都超出了我的知识范围。
我考虑改变的一件事是实际的变量名称。它对编译的代码没有什么不同，但我更喜欢更长的变量名而不是缩写，所以我选择KB/GB或类似的东西。 {{1}}很容易与常量混淆，具体取决于您的编码标准。
答案 6 :(得分：2)
理论上，这更快（预先计算常数来进行乘法而不是除法）。它可能不经常使用，但以防万一。
double const KbToGbFactor = 1d / 1024 /1024;
double gb = kb * KbToGbFactor;
答案 7 :(得分：2)
我编写了一个小型实用程序类，用于执行单元之间的转换，但是......
#region StorageDifferential
/// <summary>
/// Converts between Base 2 or Base 10 storage units [TB, GB, MB, KB, Bytes]
/// </summary>
public enum Differential : int
{
/// <summary>
/// Convert Bytes to Kilobytes
/// </summary>
ByteToKilo,
/// <summary>
/// Convert Bytes to Megabytes
/// </summary>
ByteToMega,
/// <summary>
/// Convert Bytes to Gigabytes
/// </summary>
ByteToGiga,
/// <summary>
/// Convert Bytes to Teraytes
/// </summary>
ByteToTera,
/// <summary>
/// Convert Kilobytes to Bytes
/// </summary>
KiloToByte,
/// <summary>
/// Convert Kilobytes to Megabytes
/// </summary>
KiloToMega,
/// <summary>
/// Convert Kilobytes to Gigabytes
/// </summary>
KiloToGiga,
/// <summary>
/// Convert Kilobytes to Terabytes
/// </summary>
KiloToTera,
/// <summary>
/// Convert Megabytes to Bytes
/// </summary>
MegaToByte,
/// <summary>
/// Convert Megabytes to Kilobytes
/// </summary>
MegaToKilo,
/// <summary>
/// Convert Megabytes to Gigabytes
/// </summary>
MegaToGiga,
/// <summary>
/// Convert Megabytes to Terabytes
/// </summary>
MegaToTera,
/// <summary>
/// Convert Gigabytes to Bytes
/// </summary>
GigaToByte,
/// <summary>
/// Convert Gigabytes to Kilobytes
/// </summary>
GigaToKilo,
/// <summary>
/// Convert Gigabytes to Megabytes
/// </summary>
GigaToMega,
/// <summary>
/// Convert Gigabytes to Terabytes
/// </summary>
GigaToTerra,
/// <summary>
/// Convert Terabyte to Bytes
/// </summary>
TeraToByte,
/// <summary>
/// Convert Terabyte to Kilobytes
/// </summary>
TeraToKilo,
/// <summary>
/// Convert Terabytes to Megabytes
/// </summary>
TeraToMega,
/// <summary>
/// Convert Terabytes to Gigabytes
/// </summary>
TeraToGiga,
}
#endregion
#region Storage Sizes
/// <summary>
/// Enumeration of recognized storage sizes [in Bytes]
/// </summary>
public enum StorageSizes : long
{
/// <summary>
/// Base 10 Conversion
/// </summary>
KILOBYTE = 1000,
MEGABYTE = 1000000,
GIGABYTE = 1000000000,
TERABYTE = 1000000000000,
/// <summary>
/// Base 2 Conversion
/// </summary>
KIBIBYTE = 1024,
MEBIBYTE = 1048576,
GIBIBYTE = 1073741824,
TEBIBYTE = 1099511627776,
}
#endregion
#region StorageBase
/// <summary>
/// Storage powers 10 based or 1024 based
/// </summary>
public enum StorageBase : int
{
/// <summary>
/// 1024 Base power, Typically used in memory measurements
/// </summary>
BASE2,
/// <summary>
/// 10 Base power, Used in storage mediums like harddrives
/// </summary>
BASE10,
}
#endregion
/// <summary>
/// Convert between base 1024 storage units [TB, GB, MB, KB, Byte]
/// </summary>
public static class StorageConverter
{
/// <summary>
/// Convert between base 1024 storage units [TB, GB, MB, KB, Byte]
/// </summary>
/// <param name="SizeDifferential">Storage conversion differential [enum]</param>
/// <param name="UnitSize">Size as mutiple of unit type units [double]</param>
/// <param name="BaseUnit">Size of the base power [enum]</param>
/// <returns>Converted unit size [double]</returns>
public static double Convert(Differential SizeDifferential, double UnitSize, StorageBase BaseUnit = StorageBase.BASE10)
{
if (UnitSize < 0.000000000001) return 0;
double POWER1 = 1000;
double POWER2 = 1000000;
double POWER3 = 1000000000;
double POWER4 = 1000000000000;
if (BaseUnit == StorageBase.BASE2)
{
POWER1 = 1024;
POWER2 = 1048576;
POWER3 = 1073741824;
POWER4 = 1099511627776;
}
switch (SizeDifferential)
{
case Differential.ByteToKilo:
return UnitSize / POWER1;
case Differential.ByteToMega:
return UnitSize / POWER2;
case Differential.ByteToGiga:
return UnitSize / POWER3;
case Differential.ByteToTera:
return UnitSize / POWER4;
case Differential.KiloToByte:
return UnitSize * POWER1;
case Differential.KiloToMega:
return UnitSize / POWER1;
case Differential.KiloToGiga:
return UnitSize / POWER2;
case Differential.KiloToTera:
return UnitSize / POWER3;
case Differential.MegaToByte:
return UnitSize * POWER2;
case Differential.MegaToKilo:
return UnitSize * POWER1;
case Differential.MegaToGiga:
return UnitSize / POWER1;
case Differential.MegaToTera:
return UnitSize / POWER2;
case Differential.GigaToByte:
return UnitSize * POWER3;
case Differential.GigaToKilo:
return UnitSize * POWER2;
case Differential.GigaToMega:
return UnitSize * POWER1;
case Differential.GigaToTerra:
return UnitSize / POWER1;
case Differential.TeraToByte:
return UnitSize * POWER4;
case Differential.TeraToKilo:
return UnitSize * POWER3;
case Differential.TeraToMega:
return UnitSize * POWER2;
case Differential.TeraToGiga:
return UnitSize * POWER1;
}
return 0;
}
}
答案 8 :(得分：1)
确保编译器预先计算除数：
decimal GB = KB / (1024 * 1024);
请注意，您实际上是在计算GiB（gibibyte），而不是GB（千兆字节）。如果你真的想要计算GB，那就是：
decimal GB = KB / (1000 * 1000);
答案 9 :(得分：1)
我反过来需要它，将第三方组件文字大小（例如“0字节”，“1.1 MB”）转换为通用大小（以字节为单位）。所以我用这种方式：
private static long UnformatBytes(string sizeInWords)
{
if(string.IsNullOrWhiteSpace(sizeInWords))
return -1;
string size = sizeInWords.Split(' ').FirstOrDefault();
double result;
if (string.IsNullOrWhiteSpace(size) || !double.TryParse(size, out result))
{
Debugger.Break();
return -1;
}
int pow;
if (sizeInWords.IndexOf("byte", StringComparison.OrdinalIgnoreCase) > -1)
pow = 0;
else if (sizeInWords.IndexOf("kb", StringComparison.OrdinalIgnoreCase) > -1)
pow = 1;
else if (sizeInWords.IndexOf("mb", StringComparison.OrdinalIgnoreCase) > -1)
pow = 2;
else if (sizeInWords.IndexOf("gb", StringComparison.OrdinalIgnoreCase) > -1)
pow = 3;
else if (sizeInWords.IndexOf("tb", StringComparison.OrdinalIgnoreCase) > -1)
pow = 4;
else
return -1;
return System.Convert.ToInt64((result * Math.Pow(1024, pow)));
}
答案 10 :(得分：1)
这是对JLopez的好答案的一点改进（请投票给他，不是我）。 在这里你可以选择是否有单位指示，而千位单位是用小写“k”写的（大写单位是开尔文）
//note: this is the JLopez answer!!
/// <summary>
/// Return size in human readable form
/// </summary>
/// <param name="bytes">Size in bytes</param>
/// <param name="useUnit ">Includes measure unit (default: false)</param>
/// <returns>Readable value</returns>
public static string FormatBytes(long bytes, bool useUnit = false)
{
string[] Suffix = { " B", " kB", " MB", " GB", " TB" };
double dblSByte = bytes;
int i;
for (i = 0; i < Suffix.Length && bytes >= 1024; i++, bytes /= 1024)
{
dblSByte = bytes / 1024.0;
}
return $"{dblSByte:0.##}{(useUnit ? Suffix[i] : null)}";
}
答案 11 :(得分：0)
public static string BytesToString(this long bytes, string format = "#,##0.00") {
var unitstr = new string[] { "B", "KB", "MB", "GB", "TB" };
var bytesd = Convert.ToDouble(bytes);
var unit = 0;
while (bytesd / 1024D > 1 && unit < unitstr.Length) {
unit++; bytesd /= 1024D;
}
return string.Format("{0:" + format + "}{1}", bytesd, unitstr[unit]);
}
答案 12 :(得分：0)
#region AutoFileSize
public string AutoFileSize(long number)
{
double tmp = number;
string suffix = " B ";
if (tmp > 1024) { tmp = tmp / 1024; suffix = " KB"; }
if (tmp > 1024) { tmp = tmp / 1024; suffix = " MB"; }
if (tmp > 1024) { tmp = tmp / 1024; suffix = " GB"; }
if (tmp > 1024) { tmp = tmp / 1024; suffix = " TB"; }
return tmp.ToString("n") + suffix;
}
#endregion
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