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
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
}
其他回答
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 );
这是我编的,效果很好。
public string[] DetermineDigitalSize(string filename)
{
string[] result = new string[2];
string[] sizes = { "B", "KB", "MB", "GB", "GB" };
double len = new FileInfo(filename).Length;
double adjustedSize = len;
double testSize = 0;
int order = 0;
while (order< sizes.Length-1)
{
testSize = adjustedSize / 1024;
if (testSize >= 1) { adjustedSize = testSize; order++; }
else { break; }
}
result[0] = $"{adjustedSize:f2}";
result[1] = sizes[order];
return result;
}
1-liner(加上前缀常量)
const String prefixes = " KMGTPEY";
/// <summary> Returns the human-readable file size for an arbitrary, 64-bit file size. </summary>
public static String HumanSize(UInt64 bytes)
=> Enumerable
.Range(0, prefixes.Length)
.Where(i => bytes < 1024U<<(i*10))
.Select(i => $"{(bytes>>(10*i-10))/1024:0.###} {prefixes[i]}B")
.First();
或者,如果你想减少LINQ对象的分配,使用相同的for循环变量:
/// <summary>
/// Returns the human-readable file size for an arbitrary, 64-bit file size.
/// </summary>
public static String HumanSize(UInt64 bytes)
{
const String prefixes = " KMGTPEY";
for (var i = 0; i < prefixes.Length; i++)
if (bytes < 1024U<<(i*10))
return $"{(bytes>>(10*i-10))/1024:0.###} {prefixes[i]}B";
throw new ArgumentOutOfRangeException(nameof(bytes));
}
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]);
又多了一种方法,不管怎样。我喜欢上面提到的@humbads优化解决方案,所以复制了原理,但我实现了一点不同。
我认为它是否应该是一个扩展方法是有争议的(因为不是所有的long都必须是字节大小),但我喜欢它们,当我下次需要它时,我可以在某个地方找到它!
关于单位,我想我从来没有说过“Kibibyte”或“Mebibyte”,虽然我对这种强制而非进化的标准持怀疑态度,但我认为从长远来看,这将避免混淆。
public static class LongExtensions
{
private static readonly long[] numberOfBytesInUnit;
private static readonly Func<long, string>[] bytesToUnitConverters;
static LongExtensions()
{
numberOfBytesInUnit = new long[6]
{
1L << 10, // Bytes in a Kibibyte
1L << 20, // Bytes in a Mebibyte
1L << 30, // Bytes in a Gibibyte
1L << 40, // Bytes in a Tebibyte
1L << 50, // Bytes in a Pebibyte
1L << 60 // Bytes in a Exbibyte
};
// Shift the long (integer) down to 1024 times its number of units, convert to a double (real number),
// then divide to get the final number of units (units will be in the range 1 to 1023.999)
Func<long, int, string> FormatAsProportionOfUnit = (bytes, shift) => (((double)(bytes >> shift)) / 1024).ToString("0.###");
bytesToUnitConverters = new Func<long,string>[7]
{
bytes => bytes.ToString() + " B",
bytes => FormatAsProportionOfUnit(bytes, 0) + " KiB",
bytes => FormatAsProportionOfUnit(bytes, 10) + " MiB",
bytes => FormatAsProportionOfUnit(bytes, 20) + " GiB",
bytes => FormatAsProportionOfUnit(bytes, 30) + " TiB",
bytes => FormatAsProportionOfUnit(bytes, 40) + " PiB",
bytes => FormatAsProportionOfUnit(bytes, 50) + " EiB",
};
}
public static string ToReadableByteSizeString(this long bytes)
{
if (bytes < 0)
return "-" + Math.Abs(bytes).ToReadableByteSizeString();
int counter = 0;
while (counter < numberOfBytesInUnit.Length)
{
if (bytes < numberOfBytesInUnit[counter])
return bytesToUnitConverters[counter](bytes);
counter++;
}
return bytesToUnitConverters[counter](bytes);
}
}