Clause of the
Sub and
Function statements that provides an alternate internal name.
Syntax
Usage
declare sub usablename Alias "alternatename" ( ... )
or
declare function usablename Alias "alternatename" ( ... )
or
sub usablename Alias "alternatename" ( ... )
...
end sub
or
function usablename Alias "alternatename" ( ... )
...
end function
or
type typename Alias "alternatename" ( ... )
...
end type
Description
Alias gives an alternate name to a procedure. This alternate name cannot be used within the program to call the procedure, but it is visible (if the function is not private) to the linker when linking with code written in other languages.
Alias is commonly used for procedures in libraries written in other languages when such procedure names are valid in the other language but invalid in BASIC. When using
Alias with
Declare, only the alternate name is used by the linker.
Differently from normal procedure names,
Alias does not change the case of the alternate name, so it is useful when external code requires an exported function with a particular name or with a particular case.
Alias can be used to specify an alternate name for
Type definitions.
Alias can be used as a modifier that specifies an alternate name mangling for procedure parameters. See
Alias (Modifier)
Example
If there is a sub (without parameter) called
xClearScreen in an external library and you want to reference it with the name
ClearVideoScreen, here is sample code to do so:
Declare Sub ClearVideoScreen Alias "xClearScreen" ()
If there is a function (with parameters and return value) called
MyFunctioninLib in an external library and you want to reference it with the name
myfunction, here is sample code to do so:
Declare Function myfunction Alias "MyFunctioninLib" (ByVal As Long, ByVal As Long, ByVal As ZString Ptr) As Integer
A procedure meant to be used by external C code, exported as
MyExportedProc:
Function MultiplyByFive cdecl Alias "MyExportedProc" (ByVal Parameter As Integer) As Integer Export
Return Parameter * 5
End Function
Differences from QB
- In QB, Alias only worked with Declare.
See also