Delphi customised constructor in TComponent never runs - delphi

Question

i am new to delphi and i am creating a component in delphi 6. but i can't get the constructor to run:
unit MyComms1;
...
type
TMyComms = class(TComponent)
public
constructor MyConstructor;
end;
implementation
constructor TMyComms.MyConstructor;
begin
inherited;
ShowMessage('got here');
end;
it doesn't matter what the constructor is called, but this code doesn't run the constructor at all.
edit
by request, here is how the TMyComms class is initialized (this code is in a different file called TestComms.pas):
unit TestComms;
interface
uses MyComms1, ...
type
TForm1 = class(TForm)
MyCommsHandle = TMyComms;
...
procedure BtnClick(Sender: TObject);
private
public
end;
var
Form1: TForm1;
implementation
procedure TForm1.BtnClick(Sender: TObject);
begin
MyCommsHandle.AnotherMyCommsProcedure;
end;
edit 2
reading some of the answers it looks like constructors must be manually called in delphi. is this correct? if so then this is certainly my main error - i am used to php where the __construct function is automatically called whenever a class is assigned to a handle.

Answer 1

Most likely you are not calling TMyComms.MyConstructor to test your unusual called and used constructor. The way marked with // ** would be th most usual.
type
TMyComms = class(TComponent)
public
constructor MyConstructor;
// the usual override;
// constructor Create(Owner:TComponent);override; // **
constructor Create(AOwner:TComponent);overload; override;
constructor Create(AOwner:TComponent;AnOtherParameter:Integer);overload;
end;
constructor TMyComms.Create(AOwner: TComponent);
begin
inherited ;
ShowMessage('got here Create');
end;
constructor TMyComms.Create(AOwner: TComponent; AnOtherParameter: Integer);
begin
inherited Create(AOwner);
ShowMessage(Format('got here Create with new parametere %d',[AnOtherParameter]));
end;
constructor TMyComms.MyConstructor;
begin
inherited Create(nil);
ShowMessage('got here MyConstructor');
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
TMyComms.MyConstructor.Free;
TMyComms.Create(self).Free;
TMyComms.Create(self,1234).Free;
end;

Answer 2

Your code does not follow the Delphi naming guidelines - the constructor should be named Create.
Since you didn't posted the code actually calling the ctor, I guess, that you may not have called it at all. Try to add a button to your form, doubleclick it and add the following code:
procedure TForm1.Button1Click(Sender : TObject)
var comms : TMyComms;
begin
comms := TMyComms.MyConstructor;
comms.Free;
end;
By the way, if you derive from TComponent, you should override constructor with a parameter - otherwise inherited methods may not work properly.
interface
type TMyComms = class(TComponent)
private
protected
public
constructor Create(AOwner : TComponent); override;
end;
implementation
constructor TMyComms.Create(AOwner : TComponent)
begin
inherited Create(AOwner);
// Your stuff
end;
// Somewhere in code
var comms : TMyComms;
begin
comms := TMyComms.Create(nil);
end;

Answer 3

Your custom constructor is not called because you did not call it.
MyComm := TMyComms.MyConstructor;
But you also have an error in your code. Because there is no derived constructor you can inherite with simple inherited.
type
TMyComms = class(TComponent)
public
constructor MyConstructor;
end;
implementation
constructor TMyComms.MyConstructor;
begin
inherited Create( nil ); // !
ShowMessage('got here');
end;
You can use the simple inherited if your custom constructor use the same name and parameters from an existing constructor.
type
TMyComms = class(TComponent)
public
constructor Create( AOwner : TComponent ); override;
end;
implementation
constructor TMyComms.Create( AOwner : TComponent );
begin
inherited; // <- everything is fine
ShowMessage('got here');
end;