AnimateWindow function (winuser.h)

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.

BOOL AnimateWindow(
  [in] HWND  hWnd,
  [in] DWORD dwTime,
  [in] DWORD dwFlags
);

[in] hWnd

Type: HWND

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

[in] dwTime

Type: DWORD

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

[in] 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.

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 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.

Conceptual

Other Resources

Reference

ShowWindow

WM_PRINT

WM_PRINTCLIENT

Windows