const

'{489D2CC5-D6D6-4683-8EB4-BE7AE8B58586}';

'{7DFBFAC3-98F7-4716-85EE-FBD404C906AC}';

   4:  

   5: type

interface

'{489D2CC5-D6D6-4683-8EB4-BE7AE8B58586}']

   8:     procedure SayA;

end;

  10:  

Interface

'{7DFBFAC3-98F7-4716-85EE-FBD404C906AC}']

  13:     procedure SayB;

End;

  15:  

class(TInterfacedObject, IA)

  17:     procedure SayA;

end;

  19:  

class(TInterfacedObject, IA, IB)

private

  22:     FA: TA;

public

  24:     procedure SayB;

  25:     constructor Create();

  26:     destructor Destroy; override;

implements IA;

end;

const

'{B506BE0C-07BD-41A4-8931-3DD69ABEAD82}';

'{960A6A2F-D706-48D1-BCEC-D06152B42389}';

   4:  

   5: type

interface

'{B506BE0C-07BD-41A4-8931-3DD69ABEAD82}']

   8:     procedure SayA;

function GetO: IA;

property O: IA  read GetO;

end;

  12:  

interface

'{960A6A2F-D706-48D1-BCEC-D06152B42389}']

  15:     procedure SayB;

end;

  17:  

class(TInterfacedObject, IA)

private

  20:     FO: TObject;

protected

function GetO: IA;

public

  24:     constructor Create(AOwner: TObject);

  25:     procedure SayA;

property O: IA  read GetO;

end;

  28:  

class(TInterfacedObject, IA, IB)

private

  31:     FA: TA;

public

  33:     procedure SayB;

  34:     constructor Create();

  35:     destructor Destroy; override;

Implements IA;

end;

  38: /////////////////////////////////////////////////////////////////////////////

  39: { TA }

  40:  

  41: constructor TA.Create(AOwner: TObject);

  42: begin

  43:   inherited Create;

  44:   FO:= AOwner;

error

end;

  47:  

function TA.GetO: IA;

  49: begin

  50:   Supports(FO, IID_IA, Result)

end;

  52:  

  53: procedure TA.SayA;

  54: begin

'A');

end;

  57:  

  58: { TB }

  59:  

  60: constructor TB.Create;

  61: begin

  62:   FA:= TA.Create(Self);

end;

  64:  

  65: destructor TB.Destroy;

  66: begin

  67:   FA.Free;

  68:   inherited;

end;

  70:  

  71: procedure TB.SayB;

  72: begin

'B');

end;

  75:  

  76: procedure TForm3.FormCreate(Sender: TObject);

  77: var

  78:   B : TB;

  79:   A : IA;

  80:   C : IB;

  81: begin

  82:   B:= TB.Create;

try

  84:     //获得IA接口

  85:     Supports(B, IID_IA, A);

  86:     //这里A.O属性是对A的FO进行查询IA接口 ,然后再查询IB接口

  87:     //理论上说 A的FO也就是TB对象,是实现了IA 和 IB接口的.

  88:     //但是实际这里这里C = nil

  89:     Supports(A.O, IID_IB, C);

error

finally

  92:     B.free;

end;

end;

interface

'{E28B1858-EC86-4559-8FCD-6B4F824151ED}']

function GetComponent: TComponent;

end;