An application sends messages to an animation control to open, play, stop, and close the corresponding AVI clip. Each message has one or more macros that you can use instead of sending the message explicitly.
After creating an animation control, an application sends the ACM_OPEN message to open an AVI clip and load it into memory. The message specifies either the path of an .AVI file or the name of an AVI resource. The system loads the AVI resource from the module that created the animation control.
If the animation control has the ACS_AUTOPLAY style, the control begins playing the AVI clip immediately after the .AVI file or AVI resource is opened. Otherwise, an application can use the ACM_PLAY message to start the AVI clip. An application can stop the clip at any time by sending the ACM_STOP message. The last frame played remains displayed when the control finishes playing the AVI clip or when ACM_STOP is sent.
An animation control can send two notification messages, ACN_START and ACN_STOP, to its parent window. Most applications do not handle either notification.
To close the .AVI file or AVI resource and remove it from memory, an application can use the Animate_Close macro, which sends ACM_OPEN with the filename or resource name set to NULL.