利用DirectSound从麦克风获取声音，以WAV格式存储至计算机的硬盘，并利用Graphics类显示声音文件的波形。-Catch sound from cumputer s microphone.Store it as WAV in the HDD off the computer. Draw waveform of the WAV file by using Graphics.

Petzold写的《精通windows 3D 图形程序设计》中推荐的源码。-Petzold wrote, " proficient in windows 3D graphics programming" in the recommended source.