A Universal Data Type Checker

    January 30, 2007

In many different scenarios we need to check if a string can be converted into an integer e.g.

This could be when we work with query strings and need to check if they match a certain data type.

In VB.NET you can use the IsNumeric and IsDate functions, but that’s about it.

You are left to your own data type checking logic the rest of the time.

It would be cool if we could have a method that could check all data types that is represented by strings such as integers, guids, booleans etc.

Here is a method that does just that.

It can check all the string based types and also enums.

/// <summary>
/// Checks the specified value to see if it can be
/// converted into the specified type.
/// <remarks>
/// The method supports all the primitive types of the CLR
/// such as int, boolean, double, guid etc. as well as other
/// simple types like Color and Unit and custom enum types.
/// </remarks>
/// </summary>
/// <param name="value">The value to check.</param>
/// <param name="type">The type that the value will be checked against.</param>
/// <returns<True if the value can convert to the given type, otherwise false.</returns>
public static bool CanConvert(string value, Type type)
  if (string.IsNullOrEmpty(value) || type == null)
   return false;

   System.ComponentModel.TypeConverter conv = System.ComponentModel.TypeDescriptor.GetConverter(type);
   if (conv.CanConvertFrom(typeof(string)))
    return true;
   { }

  return false;

Example of use

Let’s try some different examples

CanConvert("12", typeof(int)); // returns true
CanConvert("f637a876-9d58-4229-9559-a5e42a95fdac ", typeof(Guid)); // returns true
CanConvert("Backspace", typeof(System.ConsoleKey)); // returns true
CanConvert("10px", typeof(System.Web.UI.WebControls.Unit)); // returns true
CanConvert("red", typeof(System.Drawing.Color)); // returns true


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Mads Kristensen currently works as a Senior Developer at Traceworks located
in Copenhagen, Denmark. Mads graduated from Copenhagen Technical Academy with a multimedia degree in
2003, but has been a professional developer since 2000. His main focus is on ASP.NET but is responsible for Winforms, Windows- and
web services in his daily work as well. A true .NET developer with great passion for the simple solution.