The information in this article applies to:
- Microsoft Windows Software Development Kit (SDK) for Windows
versions 3.0 and 3.1
SUMMARY
The EXPAND file in the Software Library demonstrates how to create a dialog
box that expands to provide additional controls when the user clicks on a
button control.
Download EXPAND.EXE, a self-extracting file, from the Microsoft Software
Library (MSL) on the following services:
The remainder of this article describes the algorithm demonstrated in
the EXPAND file.
MORE INFORMATION
To use an expanding dialog box in an application, perform the
following two preparation steps:
- Design the entire dialog box and determine what controls will not
be initially visible.
- Disable these hidden controls in the dialog box template by
including the WS_DISABLED style bit. This prevents the TAB key or
the appropriate mnemonic key from giving the focus to one of the
hidden controls.
When the user clicks the "expand" button, perform the following five
steps:
- Disable the expand button using EnableWindow(hWnd, FALSE).
- Enable the previously hidden controls using EnableWindow(hWnd,
TRUE).
- Use SetFocus() to place the focus on the appropriate control.
- Use the following function to retrieve the current position and
size of the dialog:
GetWindowRect(hWndDlg, (LPRECT)&r);
- Use the following function to expand the dialog to its new size
MoveWindow(hWndDlg, r.left, r.top, r.right - r.left,
(r.bottom - r.top) + change, TRUE);
where "change" is the difference between the small size and the
large size.
Note that the MoveWindow() function can be used to expand a window in
any direction.
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