CODEWITHSUNDEEP
delphidelphi-xertti
Heinrich Ulbricht
Heinrich Ulbricht

Reputation: 10372

How to get/create anonymous method from TRttiMethod?

I want to handle a TRttiMethod as anonymous method. How could I do this?

Here is a simplified example of how I wish things to work:

Interface:

TMyClass = class
public
  // this method will be acquired via Rtti
  procedure Foo;

  // this method shall return above Foo as anonymous method
  function GetMethodAsAnonymous: TProc;
end;

Implementation:

function TMyClass.GetMethodAsAnonymous: TProc;
var
  Ctx: TRttiContext;
  RttiType: TRttiType;
  RttiMethod: TRttiMethod;
begin
  Ctx := TRttiContext.Create;
  try
    RttiType := Ctx.GetType(Self.ClassType);
    RttiMethod := RttiType.GetMethod('Foo');

    Result := ??????; // <-- I want to put RttiMethod here - but how?
  finally
    Ctx.Free;
  end;
end;

Upvotes: 4

Views: 792

Answers (1)

Rob Kennedy
Rob Kennedy

Reputation: 163247

If you really want an anonymous method, then make an anonymous method:

Result := procedure
          begin
            RttiMethod.Invoke(Self, []);
          end;

You can also construct a simple method pointer:

var
  Method: procedure of object;

TMethod(Method).Code := RttiMethod.CodeAddress;
TMethod(Method).Data := Self;
Result := Method;

The most direct way of course doesn't use RTTI at all:

Result := Foo;

Upvotes: 3

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