DateTime.TryParse 即使在设置时也能作为不同的文化工作

Question

So my string dateRangeStart goes in the format 2019-01-31 ie 31st Jan 2019

IFormatProvider culture = new CultureInfo("en-UK", true);
if (!string.IsNullOrEmpty(dateRangeStart))
{
    DateTime d = new DateTime();
    if(DateTime.TryParse(dateRangeStart, culture, DateTimeStyles.None, out d))
    {
        /// whatever
    }
}

Using the same routine, if I put in 31-01-2019 - it fails to parse. Why? I've told it that it's a UK date? Can it not recognise dd-MM-yyyy formats?! but totally ok with MM-dd-yyyy ?

Also happens if I swap culture for CultureInfo.InvariantCulture

Answer 1

Instead of TryParse , use TryParseExact . This way, you have full control over the string representation format you're attempting to parse:

if (!string.IsNullOrEmpty(dateRangeStart))
{
    DateTime d;
    if(DateTime.TryParseExact(dateRangeStart, "yyyy-MM-dd", CultureInfo.InvariantCulture, DateTimeStyles.None, out d))
    {
        /// whatever
    }
}