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 WINAPI AnimateWindow(
  _In_ HWND  hwnd,
  _In_ DWORD dwTime,
  _In_ DWORD dwFlags
);

Parameters

hwnd [in]

Type: HWND

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

dwTime [in]

Type: DWORD

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

dwFlags [in]

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

See also

Reference

ShowWindow

Conceptual

Windows

Other Resources

WM_PRINT

WM_PRINTCLIENT