外部文件的进度？是音频文件的播放时间长度吧？最直接的方法是用dmx之类的Xtras

内部变量也可以，例如MediaLength之类的。。

MediaLength contains the length of the movie, video, or sound specified in MediaLength@"IconTitle". Authorware reports the length of sounds in milliseconds and the length of movies and videos in frames. If you change the movie or sound at runtime, Authorware dynamically updates this variable.
Note: While CAV video is measured in frames, CLV video is measured in milliseconds.