DirectSound 录音测试程序。包含最基本的DirectSound设备枚举、打开和缓冲区创建。用一个环形缓冲区实现连续的音频采集并写入到文件。控制台程序，用键盘控制录音的开停。-DirectSound recording test program. Contains the most basic the DirectSound device enumeration, open and create a buffer. Implemented using a ring buffer the continuous audio acquisition and written into the file. Console program, open to stop recording keyboard control.