C# equiv of isdate?

C# equiv of isdate?

• baswegan2

  Not that I'm beating on a dead horse, but in .Net 2.0 you can use Microsoft.VisualBasic.Information.IsDate().
  

• Simple Samples

  I did that, but all that did was put 1/1/1 in the date. I guess i need someone to tell me what the exact syntax should be, since what i tried either put in a current date, if the date string i passed in is not valid, or it puts in 1/1/1 if i use nocurrentdatedefault.

  There's not enough examples in the doc for me to figure out how to use the formatter the way i need.

  
  

• Richard Wilson

  These posts were extremely helpful when trying to find the most efficient way to validate a date. But since we are in the dark ages and not using 2.0 framework, let alone 3.0 that is now out, I used the date.parse method. As far as adding another VB assembly from 6.0, well... that's probably not necessary since the any of the other above scenaries will work just fine, but to each his own. Anyway, I hope to post a pretty neat regex validator for dates in the future. Hopefully I can copy one that someone else has taken the time to write, but no such luck just yet.

  
  

• @nt

  If your input is a string, you will probably want to use regular expressions (System.Text.Regularexpressions) to create real DateTime structs (System.DateTime). You can then manipulate them in whatever way that you need to.
  

• prawin

  It might be overkill to load the VisualBasic assembly for just that one method, but if you find a need for more than a couple of the VisualBasic namespace methods that don't have direct equivalents in C#, there's nothing wrong with using that (extremely) well-tested assembly. There's such a stigma against it, but I've even seen some people recommend using other far more obscure assemblies (shareware, code from someone's blog, etc.) rather than reference the VisualBasic one. For example, the Financial methods are very useful - why reference a third-party tool or write your own if the Financial class has very solid methods tested by far more developers than that third-party tool

  Certainly, you shouldn't reference the namespace for things like "Len" or "Left" - these have obvious .NET equivalents. But for more complex methods that don't have non-VisualBasic equivalents, I don't see a problem.

  In summary, Microsoft.VisualBasic.dll is just another useful assembly that you have at your disposal. Don't dismiss it just because it has (gasp) "VisualBasic" in it's name.

  Also note that Microsoft.VisualBasic.dll is not the VB 'compatibility' dll that you certainly should avoid.

  David Anton
  www.tangiblesoftwaresolutions.com
  Instant C#: VB to C# converter
  Instant VB: C# to VB converter
  Instant C++: C# to C++ converter, VB to C++ converter
  Clear VB: Cleans up VB code
  C# Code Metrics: Quick metrics for C#

  
  
  

• JimBobJoe

  Yes, but be mindful that TryParse is only available in asp.net 2.0.
  

• estyles

  This is the code for the IsDate function that come with Microsoft.VisualBasic assembly. I got this code through reflector utility. I know that I am posting this reply after long time.

  public static bool IsDate(object Expression)
  {
     if (Expression != null)
     {
        if (Expression is DateTime)
        {
           return true;
        }
        if (Expression is string)
        {
           try
           {
              DateTime time1 = DateType.FromString((string) Expression);
              return true;
           }
           catch (Exception)
           {
           }
        }
     }
     return false;
  }
  

  
  
  

• Jamie Thomson

  It is best to use DateTime.TryParse instead of DateTime.Parse if you are just catching and ignoring the exception. Throwing exceptions via DateTime.Parse is a magnitude slower than using DateTime.TryParse, especially if you using this in a loop.

  
  
  

• John Siney

  Can't you use the VB function:

  Microsoft.VisualBasic.isdate()

   

  
  
  

• mallakishore

  In ASP.NET, when you use

  DateTime.TryParse()

  The 2nd parameter is a DateTime output parameter that will be set to the converted date if possible;

  if not possible, will be set to DateTime.MinDate;

  That's all !!!

  
  

• Krop

  That works. THanks!
  

• PaulD1

  public static bool IsDate(Object obj)
  {
  string strDate = obj.ToString();
  try
  {
  DateTime dt = DateTime.Parse(strDate);
  if(dt != DateTime.MinValue && dt != DateTime.MaxValue)
  return true;
  return false;
  }
  catch
  {
  return false;
  }
  }
  
  
  

• Keith Chapman

  If you know the format that it must be in, have a look at the DateTime.ParseExact method, otherwise use the DateTime.Parse overload that accepts a DateTimeStyles value and pass DateTimeStyles.NoCurrentDateDefault.
  
  
• C# equiv of isdate?