如何使用C＃解析日期时间字符串（包括毫秒）？

Question

I am trying to convert a datatime string "including milliseconds" into a DataTime. I tried tried to use DateTime.TryParseExact but it does not give me a milliseconds.

Here is what I have tired

public static DateTime? dateTimeVal(string raw, string format = null)
{
    DateTime final;

    if(raw != null){

        if( format != null){

            string[] formats = new[] { format };  

            if (DateTime.TryParseExact(raw, formats, CultureInfo.InvariantCulture, DateTimeStyles.None, out final))
            {
                return final;
            }
        }

        if (DateTime.TryParse(raw, out final))
        {
            return final;
        }

    }

    return null;
}

This is how I use the method above

DateTime? dt = dateTimeVal("2016-03-14 11:22:21.352", "yyyy-MM-dd HH:mm:ss.fff");

However, dt gives me this 3/14/2016 11:22:21 AM

How can I get the value to include the milliseconds?

Answer 1

DateTime final = new DateTime();
var test = DateTime.TryParseExact("2016-03-14 11:22:21.352", new string[] { "yyyy-MM-dd HH:mm:ss.fff" }, CultureInfo.InvariantCulture, DateTimeStyles.None, out final);

This works for me.

Just take care for your fff . If you write them uppercase, the milliseconds will be supressed. Lowercase they will be parsed.

The only thing away from that I can imagine is you have used .ToString without providing any format. Then you'll get:

Are you sure you've written the providing format lowercase inside your code? Also have you used .ToString() with an output-format that shows up the milliseconds?

Answer 2

If you want to get the DateTime as string with milisecond , then you can use the following code;

string dateTime = dt.Value.ToString("yyyy-MM-dd HH:mm:ss.fff", CultureInfo.InvariantCulture);                  

Hope this helps.