AnimateWindow function

Enables you to produce special effects when showing or hiding windows. There are four types of animation: roll, slide, collapse or expand, and alpha-blended fade.

Syntax

BOOL AnimateWindow(
  HWND  hWnd,
  DWORD dwTime,
  DWORD dwFlags
);

Parameters

hWnd

Type: HWND

A handle to the window to animate. The calling thread must own this window.

dwTime

Type: DWORD

The time it takes to play the animation, in milliseconds. Typically, an animation takes 200 milliseconds to play.

dwFlags

Type: DWORD

The type of animation. This parameter can be one or more of the following values. Note that, by default, these flags take effect when showing a window. To take effect when hiding a window, use AW_HIDE and a logical OR operator with the appropriate flags.

Value Meaning
AW_ACTIVATE
0x00020000
Activates the window. Do not use this value with AW_HIDE.
AW_BLEND
0x00080000
Uses a fade effect. This flag can be used only if hwnd is a top-level window.
AW_CENTER
0x00000010
Makes the window appear to collapse inward if AW_HIDE is used or expand outward if the AW_HIDE is not used. The various direction flags have no effect.
AW_HIDE
0x00010000
Hides the window. By default, the window is shown.
AW_HOR_POSITIVE
0x00000001
Animates the window from left to right. This flag can be used with roll or slide animation. It is ignored when used with AW_CENTER or AW_BLEND.
AW_HOR_NEGATIVE
0x00000002
Animates the window from right to left. This flag can be used with roll or slide animation. It is ignored when used with AW_CENTER or AW_BLEND.
AW_SLIDE
0x00040000
Uses slide animation. By default, roll animation is used. This flag is ignored when used with AW_CENTER.
AW_VER_POSITIVE
0x00000004
Animates the window from top to bottom. This flag can be used with roll or slide animation. It is ignored when used with AW_CENTER or AW_BLEND.
AW_VER_NEGATIVE
0x00000008
Animates the window from bottom to top. This flag can be used with roll or slide animation. It is ignored when used with AW_CENTER or AW_BLEND.

Return Value

Type: Type: BOOL

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. The function will fail in the following situations:

  • If the window is already visible and you are trying to show the window.
  • If the window is already hidden and you are trying to hide the window.
  • If there is no direction specified for the slide or roll animation.
  • When trying to animate a child window with AW_BLEND.
  • If the thread does not own the window. Note that, in this case, AnimateWindow fails but GetLastError returns ERROR_SUCCESS.
To get extended error information, call the GetLastError function.

Remarks

To show or hide a window without special effects, use ShowWindow.

When using slide or roll animation, you must specify the direction. It can be either AW_HOR_POSITIVE, AW_HOR_NEGATIVE, AW_VER_POSITIVE, or AW_VER_NEGATIVE.

You can combine AW_HOR_POSITIVE or AW_HOR_NEGATIVE with AW_VER_POSITIVE or AW_VER_NEGATIVE to animate a window diagonally.

The window procedures for the window and its child windows should handle any WM_PRINT or WM_PRINTCLIENT messages. Dialog boxes, controls, and common controls already handle WM_PRINTCLIENT. The default window procedure already handles WM_PRINT.

If a child window is displayed partially clipped, when it is animated it will have holes where it is clipped.

AnimateWindow supports RTL windows.

Avoid animating a window that has a drop shadow because it produces visually distracting, jerky animations.

Requirements

   
Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Target Platform Windows
Header winuser.h (include Windows.h)
Library User32.lib
DLL User32.dll

See Also

Conceptual

Other Resources

Reference

ShowWindow

WM_PRINT

WM_PRINTCLIENT

Windows