CA1406: Avoid Int64 arguments for Visual Basic 6 clients
For the latest documentation on Visual Studio 2017 RC, see Visual Studio 2017 RC Documentation.
A type that is specifically marked as visible to Component Object Model (COM) declares a member that takes a System.Int64 argument.
Visual Basic 6 COM clients cannot access 64-bit integers.
By default, the following are visible to COM: assemblies, public types, public instance members in public types, and all members of public value types. However, to reduce false positives, this rule requires the COM visibility of the type to be explicitly stated; the containing assembly must be marked with the System.Runtime.InteropServices.ComVisibleAttribute set to
false and the type must be marked with the ComVisibleAttribute set to
To fix a violation of this rule for a parameter whose value can always be expressed as a 32-bit integral, change the parameter type to System.Int32. If the value of the parameter might be larger than can be expressed as a 32-bit integral, change the parameter type to System.Decimal. Note that both System.Single and System.Double lose precision at the upper ranges of the Int64 data type. If the member is not meant to be visible to COM, mark it with the ComVisibleAttribute set to
It is safe to suppress a warning from this rule if it is certain that Visual Basic 6 COM clients will not access the type.
The following example shows a type that violates the rule.
Imports System Imports System.Runtime.InteropServices <Assembly: ComVisibleAttribute(False)> Namespace InteroperabilityLibrary <ComVisibleAttribute(True)> _ Public Class SomeClass Public Sub LongArgument(argument As Long) End Sub End Class End Namespace