播放背景音乐

声明：
Declare Function MCISendString& Lib "MMSYSTEM" (ByVal LPSTRCOMMAND$, ByVal LPSTRRETURNSTR As Any, ByVal WRETURNLEN%, ByVal HCALLBACK%)
开始播放：
R% = MCISendString&("OPEN EXAMPLE.MID TYPE SEQUENCER ALIAS NN", 0&, 0, 0)
R% = MCISendString&("PLAY NN FROM 0", 0&, 0, 0)
R% = MCISendString&("CLOSE ANIMATION", 0&, 0, 0)
停止：
R% = MCISendString&("OPEN EXAMPLE.MID TYPE SEQUENCER ALIAS NN", 0&, 0, 0)
R% = MCISendString&("STOP NN", 0&, 0, 0)
R% = MCISendString&("CLOSE ANIMATION", 0&, 0, 0)
其中EXAMPLE.MID 为播放的文件，NN为自定义名称标志。