fixed array in a structure

[sleepy tim]

Hi,

Im looking into VB.net for a project but I have come against a problem. Structures required in some DLLs have arrays of byte such as

Type WSAData
A(100) As Byte
B As Integer
End Type

The problem is I cant find out how i can replicate this structure in VB.net since you cant use Type definition but have to use Structure, in which you can only define a reference to a dynamic array.

Is there any way arround this?

thanks

[Pirate]

Ok I've tried your code but gives this msg :

Arrays declared as structure members cannot be declared with an initial sizeSee Also
Arrays | Structure Declaration
An array in a structure is declared with an initial size.

To correct this error

Define arrays in structures as dynamic.
You can re-dimension dynamic arrays with if a fixed-size array is required. For example:

Structure MyStruct
   Public MyArray() As Integer
End Structure
 
Sub UseStruct()
   Dim Struct As MyStruct
   ReDim Struct.MyArray(9) ' Dimension as 10 elements
   Struct.MyArray(2) = 777 ' Use the array.
End Sub

according to MS.

[sleepy tim]

Thanks, but thats no use. Thats a dynamic array where I need a static fixed array.. the problem is thus:

Structure MyStruct
   Public MyArray() As Integer
   Public MyInt As Integer
End Structure
 
Sub UseStruct()
   Dim Struct As MyStruct
   ReDim Struct.MyArray(9) ' Dimension as 10 elements
   Struct.MyArray(2) = 777 ' Use the array.
End Sub

would in fact produce something like the following behind the sceens:
Pointer MyArray (this uses up 4 bytes of data)
Integer MyInt (this uses up 4 bytes of data)

Somewhere else in memory a block of 10 bytes of memory is allocated and the variable MyArray references it


In contrast

Type MyStruct
   MyArray(9) As Integer
   MyInt As Integer
End Type

would produce something like the following behind the sceens:
Integer *10 MyArray (this uses up 4*10 bytes of data = 40)
Integer MyInt (this uses up 4 bytes of data)

So as you can see there is a big difference in terms of where the data is stored in memory, and the DLL im interfacing with will only accept the data in the format produced by the Type definition.

Thanks for any more help on this

[Pirate]

If I'm not wrong , you're trying to create new user-data type.Well,I've never faced such this stuff.

[brian728s]

I know this is a little old, but:

Structure Whatever
<vbfixedarray (15)> public ArrayName as Integer
End Structure

Defines a fixed array of 16 integers.

For strings, use

<vbfixedstring(15)> public StringName as String