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...send a windows message with SendMessage?
Autor: Simon Grossenbacher
Homepage: http://www.swissdelphicenter.ch
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Tip Rating (13):  
     


{
  This is useful if you want to send a message from your DLL back
  to the calling application.
}

const
  
MY_MESSAGE = WM_USER + 4242;
 
type
  
TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
    // Handler that receive the Message
    
procedure MessageReceiver(var msg: TMessage); message MY_MESSAGE;
  end;

var
  
Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.Button1Click(Sender: TObject);
var
  
txt: string;
begin
  
txt := 'Hello World';
  SendMessage(Form1.Handle, MY_MESSAGE, 0, DWORD(PChar(txt)));
end;

// To receive this custom Message that is addressed to form1.handle
// you need a message handler.

procedure TForm1.MessageReceiver(var msg: TMessage);
var
  
txt: PChar;
begin
  
txt := PChar(msg.lParam);
  msg.Result := 1;
  ShowMessage(txt);
end;


end.


 

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