Is it posible to do this casting in VB?

[active]

Function CastIt (byval z as boolean) As ??
if z then
CastIt = DirectCast(Acti veMdiChild, MyForm1)
else
CastIt = DirectCast(Acti veMdiChild, MyForm2)
end if
End Function

Can I make a function in VB that returns the result of a DirectCast.

I think what I don't know is what to use for ?? above.

Is it possible to do this in VB?
Thanks

PS
I'd use it like this

ZZ= CastIt.Getsomet hing

Where both MyForm1 and MyForm2 have the property Getsomething

I find it hard to believe the compiler would let me do that but maybe you
see a different approach.

I could do it without a function
if z then
qq = DirectCast(Acti veMdiChild, MyForm1).Getsom ething
else
qq = DirectCast(Acti veMdiChild, MyForm2).Getsom thing
end if

But I need to do it many times
Thanks

[Herfried K. Wagner [MVP]]

" active" <ac********** @a-znet.comschrieb :

Function CastIt (byval z as boolean) As ??
if z then
CastIt = DirectCast(Acti veMdiChild, MyForm1)
else
CastIt = DirectCast(Acti veMdiChild, MyForm2)
end if
End Function

Can I make a function in VB that returns the result of a DirectCast.

I think what I don't know is what to use for ?? above.

Is it possible to do this in VB?

Not really, if the method is declared in both types separately and they
share 'Form' as common base class.

However, if you define the method in a base type (base class) or implement
an interface containing the method, you can use this type as the method's
return type.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

[=?ISO-8859-1?Q?G=F6ran_Andersson?=]

active wrote:

Function CastIt (byval z as boolean) As ??
if z then
CastIt = DirectCast(Acti veMdiChild, MyForm1)
else
CastIt = DirectCast(Acti veMdiChild, MyForm2)
end if
End Function

Can I make a function in VB that returns the result of a DirectCast.

I think what I don't know is what to use for ?? above.

Is it possible to do this in VB?
Thanks

PS
I'd use it like this

ZZ= CastIt.Getsomet hing

Where both MyForm1 and MyForm2 have the property Getsomething

I find it hard to believe the compiler would let me do that but maybe you
see a different approach.

I could do it without a function
if z then
qq = DirectCast(Acti veMdiChild, MyForm1).Getsom ething
else
qq = DirectCast(Acti veMdiChild, MyForm2).Getsom thing
end if

But I need to do it many times
Thanks

You can't make a function return different data types.

What you can do is to make a base class that inherits Form and contains
the virtual method GetSomething, and let each form inherit from the base
class instead of Form and implement the GetSomething method.

Then you can cast your reference to the base class, and call the method.

--
Göran Andersson
_____
http://www.guffa.com

[Cor Ligthert [MVP]]

Hi,

Function CastIt (byval z as MyForm1, y as MyForm2) As boolean
if type of z is MyForm1 then
CastIt = DirectCast(Acti veMdiChild, MyForm1)
return true
else
CastIt = DirectCast(Acti veMdiChild, MyForm2)
return false
end if
End Function

Cor

" active" <ac********** @a-znet.comschreef in bericht
news:uC******** ******@TK2MSFTN GP03.phx.gbl...

Function CastIt (byval z as boolean) As ??
if z then
CastIt = DirectCast(Acti veMdiChild, MyForm1)
else
CastIt = DirectCast(Acti veMdiChild, MyForm2)
end if
End Function

Can I make a function in VB that returns the result of a DirectCast.

I think what I don't know is what to use for ?? above.

Is it possible to do this in VB?
Thanks

PS
I'd use it like this

ZZ= CastIt.Getsomet hing

Where both MyForm1 and MyForm2 have the property Getsomething

I find it hard to believe the compiler would let me do that but maybe you
see a different approach.

I could do it without a function
if z then
qq = DirectCast(Acti veMdiChild, MyForm1).Getsom ething
else
qq = DirectCast(Acti veMdiChild, MyForm2).Getsom thing
end if

But I need to do it many times
Thanks

[Herfried K. Wagner [MVP]]

"Cor Ligthert [MVP]" <no************ @planet.nlschri eb:

Function CastIt (byval z as MyForm1, y as MyForm2) As boolean
if type of z is MyForm1 then
CastIt = DirectCast(Acti veMdiChild, MyForm1)
return true
else
CastIt = DirectCast(Acti veMdiChild, MyForm2)
return false
end if
End Function

What would be the task this procedure solves?

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

[Tom Leylan]

Don't mean to question your need for such a function but it seems unlikely
to be of much use. In your example the variable qq would have been declared
as a given form type right? The DirectCast information would simply be lost
if it is of type Form.

Perhaps posting a little more information would help, what's the goal?
" active" <ac********** @a-znet.comwrote.. .

Function CastIt (byval z as boolean) As ??
if z then
CastIt = DirectCast(Acti veMdiChild, MyForm1)
else
CastIt = DirectCast(Acti veMdiChild, MyForm2)
end if
End Function

Can I make a function in VB that returns the result of a DirectCast.

I think what I don't know is what to use for ?? above.

Is it possible to do this in VB?

Thanks

PS
I'd use it like this

ZZ= CastIt.Getsomet hing

Where both MyForm1 and MyForm2 have the property Getsomething

I find it hard to believe the compiler would let me do that but maybe you
see a different approach.

I could do it without a function
if z then
qq = DirectCast(Acti veMdiChild, MyForm1).Getsom ething
else
qq = DirectCast(Acti veMdiChild, MyForm2).Getsom thing
end if

But I need to do it many times

Thanks

[Cor Ligthert [MVP]]

Herfried,

I don't know but I can me immage, that I have 1 special and more general
formats for my MDI form. (Not so unusual), If I than have to do something
where a cast is needed I can do this.

Cor

"Herfried K. Wagner [MVP]" <hi************ ***@gmx.atschre ef in bericht
news:O1******** ******@TK2MSFTN GP04.phx.gbl...

"Cor Ligthert [MVP]" <no************ @planet.nlschri eb:

>Function CastIt (byval z as MyForm1, y as MyForm2) As boolean
if type of z is MyForm1 then
CastIt = DirectCast(Acti veMdiChild, MyForm1)
return true
else
CastIt = DirectCast(Acti veMdiChild, MyForm2)
return false
end if
End Function

What would be the task this procedure solves?

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

[=?ISO-8859-1?Q?G=F6ran_Andersson?=]

Excuse me for saying it, but that is pure nonsense.

:: As the return value of the method is Boolean, you can not assign a
form to it.

:: You a mixing the use of parameters with the use of global/member
variables.

:: The parameter y is never used at all.

:: The type of z is always MyForm1 so the if statement is pointless.

:: Casting to the specific form class serves no purpose at all, as the
return type of a method is always the same.

:: Assigning a value to the method name serves no purpose if you are
also using Return.

Cor Ligthert [MVP] wrote:

Hi,

Function CastIt (byval z as MyForm1, y as MyForm2) As boolean
if type of z is MyForm1 then
CastIt = DirectCast(Acti veMdiChild, MyForm1)
return true
else
CastIt = DirectCast(Acti veMdiChild, MyForm2)
return false
end if
End Function

Cor

" active" <ac********** @a-znet.comschreef in bericht
news:uC******** ******@TK2MSFTN GP03.phx.gbl...

>Function CastIt (byval z as boolean) As ??
if z then
CastIt = DirectCast(Acti veMdiChild, MyForm1)
else
CastIt = DirectCast(Acti veMdiChild, MyForm2)
end if
End Function

Can I make a function in VB that returns the result of a DirectCast.

I think what I don't know is what to use for ?? above.

Is it possible to do this in VB?
Thanks

PS
I'd use it like this

ZZ= CastIt.Getsomet hing

Where both MyForm1 and MyForm2 have the property Getsomething

I find it hard to believe the compiler would let me do that but maybe you
see a different approach.

I could do it without a function
if z then
qq = DirectCast(Acti veMdiChild, MyForm1).Getsom ething
else
qq = DirectCast(Acti veMdiChild, MyForm2).Getsom thing
end if

But I need to do it many times
Thanks

--
Göran Andersson
_____
http://www.guffa.com

[Chris Dunaway]

On Mar 4, 6:34 pm, " active" <activeNOS... @a-znet.comwrote:

Function CastIt (byval z as boolean) As ??
if z then
CastIt = DirectCast(Acti veMdiChild, MyForm1)
else
CastIt = DirectCast(Acti veMdiChild, MyForm2)
end if
End Function

Can I make a function in VB that returns the result of a DirectCast.

I think what I don't know is what to use for ?? above.

Is it possible to do this in VB?

Thanks

PS
I'd use it like this

ZZ= CastIt.Getsomet hing

Where both MyForm1 and MyForm2 have the property Getsomething

I find it hard to believe the compiler would let me do that but maybe you
see a different approach.

I could do it without a function
if z then
qq = DirectCast(Acti veMdiChild, MyForm1).Getsom ething
else
qq = DirectCast(Acti veMdiChild, MyForm2).Getsom thing
end if

I'm not sure what you're attempting to accomplish. Does GetSomething
return a different type for each form?

[=?ISO-8859-1?Q?G=F6ran_Andersson?=]

Chris Dunaway wrote:

On Mar 4, 6:34 pm, " active" <activeNOS... @a-znet.comwrote:

>Function CastIt (byval z as boolean) As ??
if z then
CastIt = DirectCast(Acti veMdiChild, MyForm1)
else
CastIt = DirectCast(Acti veMdiChild, MyForm2)
end if
End Function

Can I make a function in VB that returns the result of a DirectCast.

I think what I don't know is what to use for ?? above.

Is it possible to do this in VB?

Thanks

PS
I'd use it like this

ZZ= CastIt.Getsomet hing

Where both MyForm1 and MyForm2 have the property Getsomething

I find it hard to believe the compiler would let me do that but maybe you
see a different approach.

I could do it without a function
if z then
qq = DirectCast(Acti veMdiChild, MyForm1).Getsom ething
else
qq = DirectCast(Acti veMdiChild, MyForm2).Getsom thing
end if

I'm not sure what you're attempting to accomplish. Does GetSomething
return a different type for each form?

Yes, that is what he would like to do, but i have already explained that
this is impossible.

--
Göran Andersson
_____
http://www.guffa.com