Note
Access to this page requires authorization. You can try signing in or changing directories.
Access to this page requires authorization. You can try changing directories.
By using attributes you can customize how structs are laid out in memory. For example, you can create what is known as a union in C/C++ by using the StructLayout(LayoutKind.Explicit) and FieldOffset attributes.
Example 1
In this code segment, all of the fields of TestUnion start at the same location in memory.
' Add an Imports statement for System.Runtime.InteropServices.
Structure TestUnion
Public i As Integer
Public d As Double
Public c As Char
Public b As Byte
End Structure
Example 2
The following is another example where fields start at different explicitly set locations.
' Add an Imports statement for System.Runtime.InteropServices.
Structure TestExplicit
Public lg As Long
Public i1 As Integer
Public i2 As Integer
Public d As Double
Public c As Char
Public b As Byte
End Structure
The two integer fields, i1 and i2, share the same memory locations as lg. This sort of control over struct layout is useful when using platform invocation.
See also
Collaborate with us on GitHub
The source for this content can be found on GitHub, where you can also create and review issues and pull requests. For more information, see our contributor guide.
