DirectCast very very difficoult question

Hi ,

I need a particular request.

In my project there are more then 150/200 calls to DirectCast.

I see that in C# there is an equivalent, but use a very different sintax.

In short:

I like to create a function that emulate DirectCast with another name:

My_DirectCast that inside use direct cast. To explain better the concept, something like this:

Public Function My_DirectCast(Expression , Type) as Object

 return DirectCast(Expression , Type)

End Function

and IT is not easy do this, because the compiler do not accept Type.

But after this I need a way to emulate the some situation in C#

Object My_DirectCast(Expression , Type)) {

Return (Type)Exression;


and probably this is more difficoult then the previous.

I am aware that it is not easy but I hope is possible do this.

If is possible do this I don't need to replace MANUALLY 150/200 or more code rows but only one.

Please HELP ME !!!!!
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

AndyAinscowFreelance programmer / ConsultantCommented:
The following works - but really needs error trapping to in case the conversion fails.

       public T  foo<T>(Object obj)
            return (T) Convert.ChangeType(obj, typeof(T));

        private void Form1_Load(object sender, EventArgs e)
            int i = foo<int>(23.45);
            double d = foo<double>(3.14159);
luca345Author Commented:
Hi AndyAinscow ,

Because I have a bit difficoult to understand C# can you try to do the some in ?

Thank you !!
AndyAinscowFreelance programmer / ConsultantCommented:
I thought you wanted it in C# because you gave an example in VB but said C# uses different syntax
Introduction to Web Design

Develop a strong foundation and understanding of web design by learning HTML, CSS, and additional tools to help you develop your own website.

AndyAinscowFreelance programmer / ConsultantCommented:
VB isn't my speciality.
I've done a quick bit of searching and found this:

   Public Shared Function CAnyType(Of T)(ByRef UTO As Object) As T
        Return CType(UTO, T)
    End Function

I think you call it with something like
d = CAnyType(of double)(3.14159)
i = CAnyType(of integer)(2.345)

CType should be similar to your DirectCast, I think this might work or at least get you started
luca345Author Commented:
Hi Andy ,

Not work, I have try a similar code but VB don't accepts the 2° parameter because is a Type and VB want a object or class.
AndyAinscowFreelance programmer / ConsultantCommented:
Works perfectly here - see picture
luca345Author Commented:
Hi Andy ,

Thank you for your code but the the problem is more hard.

Please see attach.

I need a function that accept the some arguments of the original directcast and return the some value.
AndyAinscowFreelance programmer / ConsultantCommented:
I don't know how the developers that wrote the compiler do the work of transferring a type in the way it is done in DirectCast.

The way it usually is done is what I showed earlier and here again using DirectCast in the function.
How one can pass a generic Type into a function
AndyAinscowFreelance programmer / ConsultantCommented:
There are always two (rather silly) other possibilities

Function CastToDouble(1.23) as Double   and so on for int, string....

Function Cast(obj, string) as object  which has a big switch statement to call the appropriate DirectCast based upon the string value
luca345Author Commented:
Hi ,

I explain better what I need:

I my project there are 100/150 calls  to DirectCast.

In my compiler I need to go to 'replace' and 'all'    'DirectCast' with 'MyDirectCast' .

In your code I can't do 'replace all' because the arguments are different:

1) Is different the order.
2) You have add 'of'.

In short I need a clone of DirectCast with identical arguments::


a = DirectCast(b , c)

a = CAnyType(b , c )


In this mode, what I replace  'DirectCast' with ' CAnyType' I don't need to change others.

I don't known if this is possible or not.
AndyAinscowFreelance programmer / ConsultantCommented:
I don't think you can do it that simply.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
luca345Author Commented:
Very good !
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Programming Languages-Other

From novice to tech pro — start learning today.