奇怪的 TimeSpan.ToString 输出

Question

我对 TimeSpan.ToString 输出中分隔天数和小时数的符号有疑问。

标准 TimeSpan 格式字符串产生不同的分隔符：

"c" 产生句点 (.) 字符
"g" 和 "G" 产生冒号（“:”）字符

示例：

// Constant format
Console.WriteLine(TimeSpan.FromDays(42).ToString("c", CultureInfo.InvariantCulture));
// Output: 42.00:00:00 (period character between days and hours)

// General short format
Console.WriteLine(TimeSpan.FromDays(42).ToString("g", CultureInfo.InvariantCulture));
// Output: 42:0:00:00 (colon character between days and hours)

// General long format
Console.WriteLine(TimeSpan.FromDays(42).ToString("G", CultureInfo.InvariantCulture));
// Output: 42:00:00:00.0000000 (colon character between days and hours)

有人知道背后的逻辑是什么吗？

但是 TimeSpan.Parse 成功解析了所有这些字符串。

Answer 1

这些字符针对这些格式进行了硬编码。

对于"c" standard format

[-][d.]hh:mm:ss[.fffffff]

对于"g" standard format

[-][d:]h:mm:ss[.FFFFFFF]

并且 "G" Format Specifier

[-]d:hh:mm:ss.fffffff

医生也说；

Unlike the "g" and "G" format specifiers, the "c" format specifier is not culture-sensitive. It produces the string representation of a TimeSpan value that is invariant and that is common to all previous versions of the .NET Framework before the .NET Framework 4. "c" is the default TimeSpan format string; the TimeSpan.ToString() method formats a time interval value by using the "c" format string.

也在Custom TimeSpan Format Strings

The .NET Framework does not define a grammar for separators in time intervals. This means that the separators between days and hours, hours and minutes, minutes and seconds, and seconds and fractions of a second must all be treated as character literals in a format string.

听起来最重要的原因是所有 .NET Framework 版本之间的一致性。也许这就是为什么他们将这种格式称为 constant :)

Answer 2

看看MSDN

The "g" TimeSpan format specifier returns the string representation of a TimeSpan value in a compact form by including only the elements that are necessary.

[-][d:]h:mm:ss[.FFFFFFF]

.....................

The "c" format specifier returns the string representation of a TimeSpan value in the following form:

[-][d.]hh:mm:ss[.fffffff]

Answer 3

MSDN - Standard TimeSpan Format Strings 上有更多详细信息。

本质上：

“c”是 Constant format：此说明符不是 culture-sensitive。格式为 [d'.']hh':'mm':'ss['.'fffffff]

“g”是 General Short format：这是文化敏感的。格式为 [-][d':']h':'mm':'ss[.FFFFFFF]

“G”是 General Long format：这是文化敏感的。格式为[-]d’:’hh’:’mm’:’ss.fffffff.

奇怪的 TimeSpan.ToString 输出

Strange TimeSpan.ToString output

c#

.net

timespan