1.ShowWindow

1.ShowWindow

原文：

The ShowWindow function sets the specified window's show state.

BOOL ShowWindow(

  HWND hWnd,     // handle to window

  int nCmdShow   // show state of window

);

 

Parameters

hWnd

Handle to 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_FORCEMINIMIZE

Windows NT 5.0 and later: Minimizes a window, even if the thread that owns the window is hung. This flag should only be used when minimizing windows from a different thread.

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, the system 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, the system 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 an application calls ShowWindow, it should use 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. 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.

Windows CE: The nCmdShow parameter does not support the following values:

SW_MAXIMIZE

SW_MINIMIZE

SW_RESTORE

SW_SHOWDEFAULT

SW_SHOWMAXIMIZED

SW_SHOWMINIMIZED

SW_SHOWMINNOACTIVE

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Requires version 1.0 or later.
  Header: Declared in winuser.h.
  Import Library: Use user32.lib.

See Also

Windows Overview, Window Functions, CreateProcess, CreateWindow, ShowOwnedPopups, STARTUPINFO, WinMain

翻译：

 ShowWindow函数设置指定窗口的显示状态。

BOOL ShowWindow(

  HWND hWnd,     // 窗口句柄

  int nCmdShow   // 窗口的显示状态

);

参数：

hWnd：窗口句柄。

nCmdShow：指定窗口如何被显示。当应用程序第一次调用ShowWindow函数时该参数被忽略，如果程序的装入程序提供STARTUPINFO结构体。另外，第一次调用该函数时，参数通过主函数的nCmdShow参数获得，在之后的调用中，参数可以是以下值：

Value

Meaning

SW_FORCEMINIMIZE

Windows NT 5.0 and later:窗口最小化，即使拥有线程的窗口被挂起，该标志用来最小化不同线程的窗口。

SW_HIDE

隐藏该窗口，激活另一窗口

SW_MAXIMIZE

最大化指定窗口

SW_MINIMIZE

最小化指定窗口，并激活z轴上最上层的窗口

SW_RESTORE

激活并显示窗口如果窗口处于最小或最大状态，系统恢复原始的尺寸和位置。应用程序可指定该标志当要恢复被最小化了的窗口时

SW_SHOW

按照当前的位置和尺寸激活并显示窗口

SW_SHOWDEFAULT

基于指定的STARTUPINFO结构体中的SW_标志设置显示方式，该结构体是开始应用程序时传递给CteateProcess函数的。

SW_SHOWMAXIMIZED

以最大化的方式，激活并显示窗口

SW_SHOWMINIMIZED

以最小化方式，激活并显示窗口

SW_SHOWMINNOACTIVE

最小化显示窗口，并保持被激活状态

SW_SHOWNA

以当前的状态显示窗口，并保持激活状态

SW_SHOWNOACTIVATE

按照近期的尺寸和位置显示窗口，并保持激活状态

SW_SHOWNORMAL

激活并显示窗口，如果窗口最小化或最大化，系统恢复它的原始位置和大小。一个应用程序在第一次显示窗口时需要指定这个标志

返回值：

        如果当前窗口处于可见状态，返回只为非零。如果窗口为隐藏状态，返回值为零。

备注：应用程序第一次调用该程序，需要使用WinMain函数的nCmdShow参数作为它的参数。以后的调用必须使用上面列表中的值。

在关于nCmdShow参数的一个著名讨论中，该值在第一次调用ShowWindow函数时被忽略，如果应用程序的装入程序在STARTUPINFO结构体指定了启动信息。如果这样的话，ShowWindow使STARTUPINFO结构体中的信息来显示窗口。在这之后的调用中，必须设置nCmdShow参数SW_SHOWDEFAULT标识，才能以启动时提供的参数显示窗口。在以下情况是使用这种方法：

应用程序通过CreatWindow函数创建主窗口，设置了WS_VISILE属性。

应用程序通过CreatWindow函数创建主窗口，清除了WS_VISILE属性，之后调用ShowWindow，设置SW_SHOW属性显示窗口。

在Window CE中nCmdShow参数不支持下列属性：略