The unmanaged code
Once the assembly is registered and properly installed, the types defined within
the assembly can be used from COM as though they were normal COM types. Now you
can create a simple VB 6 Standard EXE project type and as I already said confirm
whether you set a reference to the new generated type Library. Place this code
in the code section and now you see the usage of our .NET type in Classic COM.
Private Sub Command1_Click()
Dim a As New Calculator
MsgBox a.Add(100, 100), vbInformation, "ADDITION
(100,100)"
MsgBox a.GetType, vbInformation, "INFORMATION-TYPE"
MsgBox a.Hello("India"), vbInformation, "STRING"
MsgBox a.Subtract(100, 1), vbInformation, "SUBTRACTION(100-1)"
Dim i As Imuldiv'INTERFACE
Set i = a
MsgBox i.Multiply(100, 100), vbInformation, "MULTIPLICATION(100*100)"
MsgBox i.Division(100, 100), vbInformation, "DIVISION(100/100)"
End Sub
Summary
A lot of companies have spent a great amount of money and time in COM components.
With introduction of .NET people are worried about the future of COM. Microsoft
has recognized this and provide means to use classic COM components in .NET code
and vice versa.