c# - string.format() 不显示值

Question

谁能告诉我为什么这个 string.Format() 不显示第一个值？

long countLoop = 0;
long countTotal = 3721;

string.Format("Processed {0:#,###,###} lines of {1:#,###,###} ({2:P0})", countLoop, countTotal, ((double)countLoop / countTotal));

我得到的结果是

Processed  lines of 3,721 (0 %) 

但是如果我用数字 1 替换 countTotal

string.Format("Processed {0:#,###,###} lines of {1:#,###,###} ({2:P0})", 1, countTotal, ((double)countLoop / countTotal));

我明白了

处理了 1 行 3,721 (0 %)。

关于 string.Format 有什么我不知道的吗？

Answer 1

请参阅 the "#" custom format specifier 上的文档:

Note that this specifier never displays a zero that is not a significant digit, even if zero is the only digit in the string.

如果您想在这种情况下显示“0”，请查看 the "0" custom format specifier :

If the value that is being formatted has a digit in the position where the zero appears in the format string, that digit is copied to the result string; otherwise, a zero appears in the result string.

这应该适合你:

string.Format(
    "Processed {0:#,###,##0} lines of {1:#,###,###} ({2:P0})", 
    countLoop, countTotal, ((double)countLoop / countTotal));