ChangeTypeTo
Namespace
Summary== Changes an object's type with attention paid to nullables and generics ==Example==DateTime newDate="12/12/09".ChangeTypeTo(); ==Source
/// /// Returns an Object with the specified Type and whose value is equivalent to the specified object. /// /// An Object that implements the IConvertible interface. /// /// An object whose Type is conversionType (or conversionType's underlying type if conversionType /// is Nullable<>) and whose value is equivalent to value. -or- a null reference, if value is a null /// reference and conversionType is not a value type. /// /// /// This method exists as a workaround to System.Convert.ChangeType(Object, Type) which does not handle /// nullables as of version 2.0 (2.0.50727.42) of the .NET Framework. The idea is that this method will /// be deleted once Convert.ChangeType is updated in a future version of the .NET Framework to handle /// nullable types, so we want this to behave as closely to Convert.ChangeType as possible. /// This method was written by Peter Johnson at: ///
{ // It's a nullable type, so instead of calling Convert.ChangeType directly which would throw a // InvalidCastException (per
// determine what the underlying type is // If it's null, it won't convert to the underlying type, but that's fine since nulls don't really // have a type--so just return null // Note: We only do this check if we're converting to a nullable type, since doing it outside // would diverge from Convert.ChangeType's behavior, which throws an InvalidCastException if // value is null and conversionType is a value type. if (value
null) return null; // It's a nullable type, and not null, so that means it can be converted to its underlying type, // so overwrite the passed-in conversion type with this underlying type NullableConverter nullableConverter = new NullableConverter(conversionType); conversionType = nullableConverter.UnderlyingType; } // Now that we've guaranteed conversionType is something Convert.ChangeType can handle (i.e. not a // nullable type), pass the call on to Convert.ChangeType return Convert.ChangeType(value, conversionType); } ==Comments
SubSonic 3.0 implements this as an extension method - 2.x uses a static method on SubSonic.Sugar.Numeric.
