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Muetze1
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#5

Re: Übergabeparameter verfälscht bei Aufruf einer Funktion

  Alt 31. Mär 2005, 23:39
Moin!

1. Du hast als Vergleichsprocedure eine Methode:

Delphi-Quellcode:
{------------------------------------------------------------------------------}
{ TIntegerComparer
{------------------------------------------------------------------------------}

TIntegerComparerFunc = function(x: Integer; y: Integer): Integer Of Object;
TIntegerComparer = class
  private
    _ComparerFunc: TIntegerComparerFunc;
    function GetComparerFunc: TIntegerComparerFunc;
    procedure SetComparerFunc(func: TIntegerComparerFunc);
  public
    function Compare(x: Integer; y: Integer): Integer;
    property ComparerFunc: TIntegerComparerFunc read GetComparerFunc write SetComparerFunc;
    function DefaultComparerFunc(x: Integer; y: Integer): Integer;
    Constructor Create;
    Destructor Destroy; override;
end;

...

{------------------------------------------------------------------------------}
{ TIntegerComparer
{------------------------------------------------------------------------------}

Constructor TIntegerComparer.Create;
Begin
  _ComparerFunc := DefaultComparerFunc;
End;

{------------------------------------------------------------------------------}
Destructor TIntegerComparer.Destroy;
Begin
  Inherited;
End;

{------------------------------------------------------------------------------}
function TIntegerComparer.GetComparerFunc: TIntegerComparerFunc;
Begin
  result := _ComparerFunc;
End;

{------------------------------------------------------------------------------}
procedure TIntegerComparer.SetComparerFunc(func: TIntegerComparerFunc);
Begin
  _ComparerFunc := func;
End;

{------------------------------------------------------------------------------}
function TIntegerComparer.Compare(x: Integer; y: Integer): Integer;
begin

  if x = y then
    result := 0
  else if (x < y) then
    result := -1
  else
    result := 1;

  //exit;

  if Not Assigned(_ComparerFunc) then
    RaiseException('TIntegerComparer.Compare: Keine Vergleichsfunktion festgelegt');
  result := _ComparerFunc(x, y);
end;

{------------------------------------------------------------------------------}
function TIntegerComparer.DefaultComparerFunc(x: Integer; y: Integer): Integer;
begin
  if x = y then
    result := 0
  else if (x < y) then
    result := -1
  else
    result := 1;
end;
Oder
2. eine normale Procedure/Funktion

Delphi-Quellcode:
{------------------------------------------------------------------------------}
{ TIntegerComparer
{------------------------------------------------------------------------------}

TIntegerComparerFunc = function(x: Integer; y: Integer): Integer;
TIntegerComparer = class
  private
    _ComparerFunc: TIntegerComparerFunc;
    function GetComparerFunc: TIntegerComparerFunc;
    procedure SetComparerFunc(func: TIntegerComparerFunc);
  public
    function Compare(x: Integer; y: Integer): Integer;
    property ComparerFunc: TIntegerComparerFunc read GetComparerFunc write SetComparerFunc;
    Constructor Create;
    Destructor Destroy; override;
end;

...

{------------------------------------------------------------------------------}
function DefaultComparerFunc(x: Integer; y: Integer): Integer;
begin
  if x = y then
    result := 0
  else if (x < y) then
    result := -1
  else
    result := 1;
end;

{------------------------------------------------------------------------------}
{ TIntegerComparer
{------------------------------------------------------------------------------}

Constructor TIntegerComparer.Create;
Begin
  _ComparerFunc := DefaultComparerFunc;
End;

{------------------------------------------------------------------------------}
Destructor TIntegerComparer.Destroy;
Begin
  Inherited;
End;

{------------------------------------------------------------------------------}
function TIntegerComparer.GetComparerFunc: TIntegerComparerFunc;
Begin
  result := _ComparerFunc;
End;

{------------------------------------------------------------------------------}
procedure TIntegerComparer.SetComparerFunc(func: TIntegerComparerFunc);
Begin
  _ComparerFunc := func;
End;

{------------------------------------------------------------------------------}
function TIntegerComparer.Compare(x: Integer; y: Integer): Integer;
begin

  if x = y then
    result := 0
  else if (x < y) then
    result := -1
  else
    result := 1;

  //exit;

  if Not Assigned(_ComparerFunc) then
    RaiseException('TIntegerComparer.Compare: Keine Vergleichsfunktion festgelegt');
  result := _ComparerFunc(x, y);
end;
MfG
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