Universal data type checker

Published Jan 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)))
      { try { conv.ConvertFrom(value); return true;
      } catch {
      } } 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

Example of use

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