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SrcollBar1.Enable := false;                    

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procedure TForm1.Button1Click(Sender: TObject);
begin
Form1.HorzScrollBar.Range := 10000;
Form1.VertScrollBar.Range := 10000;
EnableScrollBar(Form1.Handle, SB_BOTH, ESB_DISABLE_RTDN or ESB_DISABLE_LTUP);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
EnableScrollBar(Memo1.Handle, SB_BOTH, ESB_DISABLE_RTDN or ESB_DISABLE_LTUP);
end;

//Ausblenden - einzeln oder beide
procedure TForm1.Button3Click(Sender: TObject);
begin
ShowScrollBar(Memo1.Handle,SB_HORZ,False);
ShowScrollBar(Memo1.Handle,SB_VERT,False);
end;

//Einblenden - einzeln oder beide
procedure TForm1.Button4Click(Sender: TObject);
begin
ShowScrollBar(Memo1.Handle,SB_HORZ,TRUE);
ShowScrollBar(Memo1.Handle,SB_VERT,TRUE);
end;