RETURN-VALUE-DLL-TYPE attribute

Specifies the expected data type returned from a Windows Dynamic Link Library (DLL) routine.

Data type: CHARACTER

Access: Readable/Writable

Applies to: Call object handle

The RETURN-VALUE-DLL-TYPE attribute must be assigned before invoking the call object's INVOKE( ) method. After invocation, RETURN-VALUE contains an equivalent ABL data type which matches RETURN-VALUE-DLL-TYPE as shown in the following table.

Mapping RETURN-VALUE-DLL-TYPE to RETURN-VALUE
RETURN-VALUE-DLL-TYPE RETURN-VALUE
BYTE INTEGER
CHARACTER CHARACTER
DOUBLE DECIMAL
FLOAT DECIMAL
INT64 INT64
LONG INTEGER
MEMPTR MEMPTR
SHORT INTEGER
UNSIGNED-LONG INT64
UNSIGNED-SHORT INTEGER

For example, if a DLL function is expected to return a LONG value, then RETURN-VALUE-DLL-TYPE is set to "LONG" before executing the INVOKE( ) method. After the invocation, RETURN-VALUE-DATA-TYPE has a value of "INTEGER" and RETURN-VALUE contains an INTEGER value.

If RETURN-VALUE-DLL-TYPE is not set, the DLL routine's return value is ignored, and RETURN-VALUE is set to the Unknown value (?).

See also

INVOKE( ) method (Handle), RETURN-VALUE attribute