检测声卡是否安装

/// <summary>
        /// The waveOutGetNumDevs function retrieves the number of waveform-audio output devices present in the system.
        /// </summary>
        /// <returns>Returns the number of devices. A return value of zero means that no devices are present or that an error occurred.</returns>
        [DllImport("winmm.dll", EntryPoint = "waveOutGetNumDevs")]
        public static extern int waveOutGetNumDevs();