ShowWindow
The ShowWindow
function sets the specified window s show state.
BOOL ShowWindow(
|
HWND hWnd, |
// handle of window |
|
int nCmdShow |
// show state of
window |
|
); |
|
Parameters
hWnd
Identifies
the window.
nCmdShow
Specifies how
the window is to be shown. This parameter is ignored the first time an
application calls ShowWindow, if the program that launched the
application provides a STARTUPINFO structure. Otherwise, the first time ShowWindow
is called, the value should be the value obtained by the WinMain function in its nCmdShow
parameter. In subsequent calls, this parameter can be one of the following
values:
|
Value |
Meaning |
|
SW_HIDE |
Hides the
window and activates another window. |
|
SW_MAXIMIZE |
Maximizes
the specified window. |
|
SW_MINIMIZE |
Minimizes
the specified window and activates the next top-level window in the Z order. |
|
SW_RESTORE |
Activates
and displays the window. If the window is minimized or maximized, Windows
restores it to its original size and position. An application should specify
this flag when restoring a minimized window. |
|
SW_SHOW |
Activates
the window and displays it in its current size and position. |
|
SW_SHOWDEFAULT |
Sets the
show state based on the SW_ flag specified in the STARTUPINFO structure passed to the CreateProcess function by the program
that started the application. |
|
SW_SHOWMAXIMIZED |
Activates
the window and displays it as a maximized window. |
|
SW_SHOWMINIMIZED |
Activates
the window and displays it as a minimized window. |
|
SW_SHOWMINNOACTIVE |
Displays
the window as a minimized window. The active window remains active. |
|
SW_SHOWNA |
Displays the
window in its current state. The active window remains active. |
|
SW_SHOWNOACTIVATE |
Displays a
window in its most recent size and position. The active window remains
active. |
|
SW_SHOWNORMAL |
Activates
and displays a window. If the window is minimized or maximized, Windows
restores it to its original size and position. An application should specify
this flag when displaying the window for the first time. |
Return Values
If the window
was previously visible, the return value is nonzero.
If the window
was previously hidden, the return value is zero.
Remarks
The first
time a program calls ShowWindow, it uses the WinMain function s nCmdShow
parameter as its nCmdShow parameter. Subsequent calls to ShowWindow
must use one of the values in the given list, instead of the one specified by
the WinMain function s nCmdShow parameter.
As noted in
the discussion of the nCmdShow parameter, the nCmdShow value is
ignored in the first call to ShowWindow if the program that launched the
application specifies startup information in the STARTUPINFO structure. In this case, ShowWindow
uses the information specified in the STARTUPINFO structure to show the
window. On subsequent calls, the application must call ShowWindow with nCmdShow
set to SW_SHOWDEFAULT to use the startup information provided by the program
that launched the application. For example, Program Manager specifies that
applications start with a minimized main window. This behavior is designed for
the following situations:
Applications create their main
window by calling CreateWindow with the WS_VISIBLE flag set.
Applications create their main
window by calling CreateWindow with the WS_VISIBLE flag cleared, and
later call ShowWindow with the SW_SHOW flag set to make it visible.
See Also