Tips dan Trik Delphi

  private
    { Private declarations }
     InsertOn : bool;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Memo1KeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
     if (Key = VK_INSERT) and (Shift = []) then
        Inserton := not InsertOn;
end;

procedure TForm1.Memo1KeyPress(Sender: TObject; var Key: Char);
begin
     if ((Memo1.SelLength = 0) and (not InsertOn)) then
        Memo1.SelLength := 1;
end;

procedure TForm1.SetHorizontalScrollBar(lb :TListBox);
var
i, MaxWidth: integer;
begin
    MaxWidth := 0;
    for i := 0 to lb.Items.Count - 1 do
    if MaxWidth < lb.Canvas.TextWidth(lb.Items[i]) then
        MaxWidth := lb.Canvas.TextWidth(lb.Items[i]);
        SendMessage(lb.Handle, LB_SETHORIZONTALEXTENT, MaxWidth + 5, 0);
end;

procedure TForm1.BitBtn1Click(Sender: TObject);
begin
     SetHorizontalScrollBar(ListBox1);
end;

procedure ShowDesktop(const YesNo : boolean);
var h : THandle;
begin
    h := FindWindow('ProgMan', nil);
    h := GetWindow(h, GW_CHILD);
    if YesNo = True then
        ShowWindow(h, SW_SHOW)
    else
        ShowWindow(h, SW_HIDE);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
     ShowDesktop(True);
end;

procedure SaveStringToFile(const aFilename: TFilename; const aString: string);
var
  SL: TStringList;
begin
  SL := TStringList.Create; // call outside the try 
  try
    SL.Text := aString;
    SL.SaveToFile(aFilename);
  finally
    SL.Free // will be called no matter what happens above
  end;
end;

  private
    { Private declarations }
  public
    { Public declarations }
    Function hitung : longint; overload;
    Function hitung(a, b : integer) : longint; overload;
  end;

var
  Form1: TForm1;
  c, d : integer;

implementation

{$R *.dfm}

Function TForm1.hitung : longint;
Begin
     result := c + d;
End;

Function TForm1.hitung(a, b : integer) : longint;
Begin
     result := a + b;
End;

end.

procedure TForm1.ShowHint(Sender: TObject);
begin
StatusBar1.SimpleText := Application.Hint;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
Application.OnHint := ShowHint;
end;

private
    { Private declarations }
  public
    { Public declarations }
     Edits: array[0..5] of TEdit;
  end;


procedure TForm1.FormCreate(Sender: TObject);
var
i: integer;
begin
    for i := 0 to 5 do
    begin
        Edits[i] := TEdit.Create(Self);
        with Edits[i] do
        begin
            Parent := Self;
            SetBounds(10, 10 + i*50, 200, 40);
            Tag := i; //each control should remember its index
            OnChange := EditChange; //same event handler for all controls
        end;
    end;
end;

procedure TForm1.EditChange(Sender: TObject);
var
i: integer;
begin
     i := TEdit(Sender).Tag;
     ShowMessage(Format('Anda menekan Edit[%d]',[i]));
end;

procedure TForm1.Panel1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
     ReleaseCapture;
     panel1.Perform(WM_SYSCOMMAND, $f012, 0)
end;

procedure TForm1.SetTransparent(hWnd: longint; value: byte);
var
style: integer;
begin
    style := GetWindowLong(hWnd, GWL_EXSTYLE);
    if value < 255 then
    begin
        style := style Or WS_EX_LAYERED;
        SetWindowLong(hWnd, GWL_EXSTYLE, style);
        SetLayeredWindowAttributes(hWnd, 0, value, LWA_ALPHA);
    end else
    begin
        style := style xor WS_EX_LAYERED;
        SetWindowLong(hWnd, GWL_EXSTYLE, style);
    end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
     SetTransparent(Handle, 200);
end;

procedure TForm1.SetTopmost(form: TForm; topmost: boolean);
begin
    if topmost then
       SetWindowPos(form.Handle, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE or SWP_NOSIZE)
    else
       SetWindowPos(form.Handle, HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOMOVE or SWP_NOSIZE);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
     SetTopmost(form1, true);
end;