(Connected to above)
Code:
Now, the code is now listed below, some of which have no code given above, but they are also very important. It is convenient for everyone to browse. Please take a closer look at the following code to get the information you need, of course, this article is just just A simple example, raised some common problems and solutions, as well as a possible application of interface programming like this.
Interface: ifoo = interface;
Ifoomanager = interface
['{3A10DC39-4B14-4C61-B657-E445C55408B6}']
Function Createafoo: IFOO;
Procedure delafoo (ID: integer);
Function Getfoonum: integer;
Function getfoobyid (ID: integer): IFOO;
END;
Ifoo = interface
// We have to maintain the object, only a simple addition operation as an example
['{22C541AA-0BA4-4092-B0EB-D267AB1FF001}']
Function FooAdd (X, Y: Integer): Integer;
END;
Tfoo's statement and implementation: Tfoo = Class (TMYINTERFAedObject, IFOO)
protected
Function FooAdd (X, Y: Integer): Integer;
END;
IMPLEMENTATION
{Tfoo}
Function TFOOAD (X, Y: Integer): Integer;
Begin
Result: = x y;
END;
Factory category and implementation:
TFOOManager = Class (TMYINTERFAedObject, Ifoomanager)
Private
Flist: array of tfoo;
Foonum: integer;
protected
Constructor crete;
Function Createafoo: IFOO;
Procedure delafoo (ID: integer);
Function Getfoonum: integer;
Function getfoobyid (ID: integer): IFOO;
public
DESTRUCTOR DESTROY; OVERRIDE;
END;
VAR
Fooman: tfoomanager;
IMPLEMENTATION
{Tfoomanager}
Constructor tfoomanager.create;
Begin
FOONUM: = 0;
END;
Function Tfoomanager.createafoo: Ifoo;
Begin
Inc (FOONUM);
if Length (Flist) SETLENGTH (Flist, Foonum * 2); FLIST [foonum-1]: = tfoo.create; Result: = flist [fumbum-1] as ifoo; END; Procedure tfoomanager.delafoo (ID: integer); VAR i: integer; Begin IF foonum> 0 THEN Begin FLIST [ID] .free; For i: = id to foonum-2 do Begin FLIST [I]: = flist [i 1]; END; FLIST [FOONUM-1]: = NIL; Dec (fumbum); END; END; Destructor tfoomanager.destroy; // Release all maintained object VAR before release the factory class i: integer; Begin For i: = 0 to foonum-1 do Begin FLIST [I] .free; FLIST [I]: = NIL; END; Finalize (FLIST); inherited; END; Function tfoomanager.getfoobyid (ID: integer): IFOO; Begin Result: = flist [id] as impoo; END; Function Tfoomanager.getfoonum: integer; Begin Result: = foonum; END; There are only two export functions in the DLL: Function Getfoomanintf: ifoomanager; stdcall; Begin IF not assigned (fooman) THEN Begin Fooman: = tfoomanager.create; END; Result: = foom as impoomanager; END; PROCEDURE FREELIB; STDCALL; // Release factory class Begin IF assigned (fooman) THEN Begin Foom.Free; Fooman: = NIL; END; END;
