DateTime.ParseExact string format exception

I am trying to convert a string into datetime with the following C# code,

DateTime dTo = DateTime.ParseExact(dateTo, "mm/dd/yyyy", CultureInfo.InvariantCulture);

eachtime I开发者_运维知识库 pass dateTo as 1/1/2010 it fails, instead it needs the string to be 01/01/2010.

What string format should I use to support both 01/01/2010 and 1/1/2010?

Using the following date format expression will allow you to use either single or double digit day and month elements.

"M/d/yyyy"

Note that the capital M is significant - a lower case m is the placeholder for minutes.

You will find more information related to date format strings here.

You can use the following Powershell command to test them.

[DateTime]::ParseExact('01/01/2010', 'M/d/yyyy', $null)

Capital M is month, little m is mins i think.

But to the point of the question, use Parse. ParseExact implies you know the exact format of the input.

You could try this format: MM/dd/yyyy, but I think there's no single format string that could support both inputs. You could test if the length of your dateTo string is less than 10 characters use M/d/yyyy, otherwise MM/dd/yyyy.