The difference between NotSupportedException and NotImplementedException

NotImplementedException

Mehran Nikoo's Notes — Tue, 23 Oct 2007 19:44:44 GMT

NotImplementedException is raised when the body of a type member has yet to be implemented. In some applications

NotImplementedExceptionShouldNotBeThrown

Managed from down under — Wed, 22 Sep 2004 15:58:00 GMT

NotImplementedExceptionShouldNotBeThrown

Managed from down under — Wed, 22 Sep 2004 14:05:00 GMT

NotImplementedExceptionShouldNotBeThrown

Managed from down under — Sun, 19 Sep 2004 15:55:00 GMT

NotImplementedExceptionShouldNotBeThrown

Managed from down under — Sun, 19 Sep 2004 15:48:00 GMT

NotSupportedException e NotImplementedException

Web Log di Gianluca Carucci — Fri, 27 Aug 2004 19:37:00 GMT

re: The difference between NotSupportedException and NotImplementedException

David M. Kean — Tue, 10 Aug 2004 05:01:00 GMT

After what Ron said, I had a crack at implementing a simple rule to check for members that throw a NotImplementException.

The rule inherits off a base class provided at http://managedfromdownunder.blogspot.com/2004/08/hello-world-and-fxcop-rules.html">http://managedfromdownunder.blogspot.com/2004/08/hello-world-and-fxcop-rules.html

public class NotImplementedExceptionShouldNotBeThrown : AusSoftIntrospectionRule
{
public NotImplementedExceptionShouldNotBeThrown() : base("NotImplementedExceptionShouldNotBeThrown")
{
}

public override Problem[] Check(Method method)
{
TypeNodeList nodes = RuleUtilities.UnhandledExceptions(method, 1, UnhandledExceptionSearchScope.Unrestricted);

for (int i = 0; i < nodes.Length; i++)
{
if (nodes[i].GetRuntimeType().IsAssignableFrom(typeof(NotImplementedException)))
{
return Problems.AsArray(GetResolution(method.Name.Name, method.DeclaringType.Name.Name));
}
}

return null;
}

public override ProtectionLevels NestedTypeProtectionLevel
{
get { return ProtectionLevels.All; }
}

public override ProtectionLevels MemberProtectionLevel
{
get { return ProtectionLevels.All; }
}

public override ProtectionLevels TypeProtectionLevel
{
get { return ProtectionLevels.All; }
}
}

It needs a bit of work, but it does the job for now.

I have posted another FxCop rule at my blog and also to post a few more rules over the next few weeks.

http://managedfromdownunder.blogspot.com/

re: The difference between NotSupportedException and NotImplementedException

Ken — Tue, 03 Aug 2004 12:21:00 GMT

I really hate NotSupportedExceptions - they reek of poorly designed interfaces. Implementing an interface is a contract to satisfy the methods defined by the interface and "not supported" is the class designer thumbing his nose at that contract.

It's probably the biggest reason I dislike Java's collections, though I think they did a better job in terms of heirarchy and naming than the .Net collections (I really want to smack the guy who decided to use "List" to refer to array based sequences). The .Net collections certainly aren't innocent of NotSupported abuses, either.

NotImplemented exceptions are a valuable development-time tool, but as you indicated, they should never see the light of day in production code.

re: The difference between NotSupportedException and NotImplementedException

Roy Green — Mon, 02 Aug 2004 22:39:00 GMT

Actually that's more of a "Says You" type of question.

Exception Design: NotSupportedException or NotImplementedException

Ken Brubaker — Mon, 02 Aug 2004 17:36:00 GMT

Brad Abrams elucidates the difference between NotSupportedException and NotImplementedException.