Re: Question on Explicit Conversion

"Ben Voigt [C++ MVP]" <bvoigt@newsgroup.nospam>
Tue, 16 Jun 2009 23:55:48 -0500
"George" <> wrote in message

Dear All,

I am puzzled with explicit conversion between string and boolean. I have a
simple Windows application with four textboxes. I validate them and store
the string true or false in their tag property, for example
this.txtname.Tag = true.

In the end I want to enable the Submit button only if all textboxes have
valid user input. I try to do this as follows:
this.btnSubmit.enabled = ((bool) this.txtname.Tag && (bool)
this.txtzip.Tag) - tried this both with && and &.

When I run it, most of the times I get an InvalidCastException (the funny
thing is the code comes from a book).

Could somebody please shed some light as to why this is the case (I got it
working with Convert.ToBoolean, but I am curious as to why I can do
explicit casting - to the best of my knowledge, if a string has the value
true, then its boolean counterpart will be true and false otherwise.

C++ hasn't got properties like Tag, a type named InvalidCastException, or a
function named Convert::ToBoolean

Perhaps you meant to ask in one of these groups?

microsoft.public.dotnet.languages.csharp -- for C# -- for C++/CLI

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