🚀 go-pugleaf

The easiest way of resizing a control at run time is to use
the undocumented Windows constants wParam (see SendMessage win32 API
or Perform VCL function that encapsulates SendMessage) that I discovered
while experimenting with these functions:

The mouse functionality is as follows:
Right Button of the Mouse triggers the actions given in the table below.
Right Button of the mouse stops the actions.

The differences are subtle, for example the behaviour for
0xF007  and 0xF008 differs in the minimum size of the control
along the axes.

Example:

WParam (Perform)
wParam (SendMessage)     Behaviour
-----------------------------------------------------------
0xF009          Adjusts control Position
-----------------------------------------------------------
0xF008          Adjusts both control Width and Height
-----------------------------------------------------------
0xF007          Adjusts both control Width and Height
-----------------------------------------------------------
0xF006          Adjusts control Height
-----------------------------------------------------------
0xF003          Adjusts control Height
-----------------------------------------------------------
0xF002          Adjusts control Width
-----------------------------------------------------------
0xF001          Adjusts control Width
-----------------------------------------------------------

TBitBtn* BitBtn1;
TButton* Button1;
TPanel*  Panel1;
//--------------------------------------------------------------------------
-
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
    Width = 600;
    Height = 300;
    Color = (TColor)0x653dca;
    Position = poScreenCenter;

    Button1 = new TButton(this);
    Button1->Parent  = this;
    Button1->Top     = 50;
    Button1->Width   = 150;
    Button1->Left    = Width/2 - Button1->Width/2;
    Button1->Height  = 100;
    Button1->Caption = "Button1";
    Button1->OnMouseDown = Button1MouseDown;
    Button1->OnClick = Button1Click;

    BitBtn1 = new TBitBtn(this);
    BitBtn1->Parent  = this;
    BitBtn1->Top     = Button1->Top;
    BitBtn1->Left    = Button1->Left - Button1->Width - 50;
    BitBtn1->Width   = Button1->Width;
    BitBtn1->Height  = Button1->Height;
    BitBtn1->Caption = "BitBtn1";
    BitBtn1->OnMouseDown = BitBtn1MouseDown;
    BitBtn1->OnClick = BitBtn1Click;

    Panel1 = new TPanel(this);
    Panel1->Parent  = this;
    Panel1->Top     = Button1->Top;
    Panel1->Left    = Button1->Left + Button1->Width + 50;
    Panel1->Width   = Button1->Width;
    Panel1->Height  = Button1->Height;
    Panel1->Caption = "Panel1";
    Panel1->OnMouseDown = Panel1MouseDown;
    Panel1->OnClick    = Panel1Click;
}
//----------------------------------------------------------------------
void __fastcall TForm1::BitBtn1Click(TObject *Sender)
{
    //ShowMessage("BitBtn1 Click");
}
//----------------------------------------------------------------------
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    //ShowMessage("Button1 Click");
}
//----------------------------------------------------------------------
void __fastcall TForm1::Panel1Click(TObject *Sender)
{
    //ShowMessage("Panel1 Click");
}
//----------------------------------------------------------------------
void __fastcall TForm1::BitBtn1MouseDown(TObject *Sender,
      TMouseButton Button, TShiftState Shift, int X, int Y)
{
// Adjust control Width by setting either WParam = 0xF001 or WParam = 0xF002
    if (Button == mbRight)
        BitBtn1->Perform(WM_SYSCOMMAND, 0xF001, 0);
}
//----------------------------------------------------------------------
void __fastcall TForm1::Button1MouseDown(TObject *Sender,
      TMouseButton Button, TShiftState Shift, int X, int Y)
{
// Adjust control Height by setting WParam = 0xF003 or  WParam = 0xF006
    if (Button == mbRight)
        Button1->Perform(WM_SYSCOMMAND, 0xF006, 0);
}
//----------------------------------------------------------------------
void __fastcall TForm1::Panel1MouseDown(TObject *Sender,
      TMouseButton Button, TShiftState Shift, int X, int Y)
{

// Adjust both control Width and control Height by setting WParam = 0xF007
    if (Button == mbRight)
        Panel1->Perform(WM_SYSCOMMAND, 0xF007, 0);
}


Rodolfo


"Sky" <huangc@motic.com.cn> wrote in message
news:3f345db9@newsgroups.borland.com...
> Hi all,
>
> As everybody know we can change the postion and size when design-time,
> but how to do it when run-time, I know how to move a control, use drag and
> dock,
> but how to resize it? TIA
>
> Sky
>
>