Visual C++ and MFC Programming 2nd Edition

Visual C++ and MFC Fundamentals Chapter 15: Fundamental Controls

value lets the pWndInsertAfter be performed but the

window will not be activated

SWP_NOCOPYBITS Normally, after a window has been repositioned, its

controls are restored to their corresponding relative

locations and dimensions. It you want this validation to

be ignored, pass this value

SWP_NOOWNERZORDER

SWP_NOREPOSITION

If this value is passed, this method will not reposition

the windows in the z coordinate

SWP_NOREDRAW When this value is set, the client area of the window

will not be redrawn

SWP_NOSENDCHANGING When this value is set, the window cannot receive a

WM_WINDOWPOSCHANGING message

SWP_SHOWWINDOW Displays the window

In the following example, a window named m_Panel is repositioned and resized:

void CTestDialog::OnBtnMovePanel()

{

// TODO: Add your control notification handler code here

m_Panel.SetWindowPos(NULL, 40, 72, 100, 86, SWP_NOZORDER);

}

14.2.5..The Handle or Pointer to a Window.................................................

Once a control has been created, its identifier set, its location and its dimensions

specified, you and your users can exploit it. On one hand, the user can type a value, select

text, scroll or control or click something. One of your jobs as a programmer is to predict

as many actions as the user may want to perform on your control(s) and take appropriate

actions. We have learned that one good way you can refer to a control in your code

consists of first providing it with an identifier. Another prerequisite you can take is to

declare and associate a control and/or a value variable for your control. Sometimes you

will not have declared a control variable for a control but at one time you need to refer to

it. One way you can do this is to use the control’s identifier and cast it to its

corresponding class. This can be taken care of by calling the CWnd::GetDlgItem()

method. It comes in two versions as follows:

CWnd* GetDlgItem(int nID) const;

void CWnd::GetDlgItem(int nID, HWND* phWnd) const;

By providing the nID argument as the identifier of the control to this method, you can

get a pointer to its class. To do this, you can declare a pointer to the class of the control,

then call the GetDlgItem() method. Because GetDlgItem() returns a CWnd pointer, using

the features of inheritance, cast this return value to the class of the control.

Practical Learning: Accessing a Window’s Handle

1. The Geometry application should still be opened.
   Open the OnClickedBnUcalc() event of the CGeom3D class


2. To get handles to the edit boxes on the dialog, implement the event as follows:

void CGeome3D::OnBnClickedBtnUcalc()

{

// TODO: Add your control notification handler code here

// Related Calculations of the cube