Convert String to Date in .NET if my incoming date format is in YYYYMMDD

Use DateTime.ParseExact(). Something like:

   string date = "20100102";
   DateTime datetime = DateTime.ParseExact(date, "yyyyMMdd", CultureInfo.InvariantCulture);

 DateTime.TryParseExact(myDateString, "yyyyMMdd", 
                         CultureInfo.InvariantCulture, 
                         DateTimeStyles.None, out myDateVar )

Check DateTime.ParseExact or DateTime.TryParseExact.

use DateTime.TryParseExact with a pattern string of "yyyyMMdd" if you are on .NET 2.0 or better.

If you are stuck with .NET 1.1 use DateTime.ParseExact

see Standard DateTime Format Strings for the rules for making pattern strings.

DateTime yourDateTime = DateTime.ParseExact(yourString, "yyyyMMdd", null);

Using TryParseExact is generally nicer than ParseExact as it won't throw an exception if the conversion fails. Instead it returns true if it's successful, false if it's not:

DateTime dt;
if (DateTime.TryParseExact("20100202", "yyyyMMdd", CultureInfo.InvariantCulture, DateTimeStyles.None, out dt))
{
   Console.WriteLine(dt.ToString());
}