webbrowser 静音(刷新、点击网页的声音)（包括flash静音）

  public enum INTERNETFEATURELIST
         {
             FEATURE_OBJECT_CACHING = 0,
             FEATURE_ZONE_ELEVATION = 1,
             FEATURE_MIME_HANDLING = 2,
             FEATURE_MIME_SNIFFING = 3,
             FEATURE_WINDOW_RESTRICTIONS = 4,
             FEATURE_WEBOC_POPUPMANAGEMENT = 5,
             FEATURE_BEHAVIORS = 6,
             FEATURE_DISABLE_MK_PROTOCOL = 7,
             FEATURE_LOCALMACHINE_LOCKDOWN = 8,
             FEATURE_SECURITYBAND = 9,
             FEATURE_RESTRICT_ACTIVEXINSTALL = 10,
             FEATURE_VALIDATE_NAVIGATE_URL = 11,
             FEATURE_RESTRICT_FILEDOWNLOAD = 12,
             FEATURE_ADDON_MANAGEMENT = 13,
             FEATURE_PROTOCOL_LOCKDOWN = 14,
             FEATURE_HTTP_USERNAME_PASSWORD_DISABLE = 15,
             FEATURE_SAFE_BINDTOOBJECT = 16,
             FEATURE_UNC_SAVEDFILECHECK = 17,
             FEATURE_GET_URL_DOM_FILEPATH_UNENCODED = 18,
             FEATURE_TABBED_BROWSING = 19,
             FEATURE_SSLUX = 20,
             FEATURE_DISABLE_NAVIGATION_SOUNDS = 21,
             FEATURE_DISABLE_LEGACY_COMPRESSION = 22,
             FEATURE_FORCE_ADDR_AND_STATUS = 23,
             FEATURE_XMLHTTP = 24,
             FEATURE_DISABLE_TELNET_PROTOCOL = 25,
             FEATURE_FEEDS = 26,
             FEATURE_BLOCK_INPUT_PROMPTS = 27,
             FEATURE_ENTRY_COUNT = 28
         }

        private const int SET_FEATURE_ON_THREAD = 0x00000001;
         private const int SET_FEATURE_ON_PROCESS = 0x00000002;
         private const int SET_FEATURE_IN_REGISTRY = 0x00000004;
         private const int SET_FEATURE_ON_THREAD_LOCALMACHINE = 0x00000008;
         private const int SET_FEATURE_ON_THREAD_INTRANET = 0x00000010;
         private const int SET_FEATURE_ON_THREAD_TRUSTED = 0x00000020;
         private const int SET_FEATURE_ON_THREAD_INTERNET = 0x00000040;
         private const int SET_FEATURE_ON_THREAD_RESTRICTED = 0x00000080;

        [DllImport("urlmon.dll")]
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.Error)]
         static extern int CoInternetSetFeatureEnabled(
              INTERNETFEATURELIST FeatureEntry,
              [MarshalAs(UnmanagedType.U4)] int dwFlags,
              bool fEnable);

        [DllImport("winmm.dll")]
        public static extern int waveOutGetVolume(IntPtr h, out uint dwVolume);

        [DllImport("winmm.dll")]
        public static extern int waveOutSetVolume(IntPtr h, uint dwVolume);

        private void Form1_Load(object sender, EventArgs e)
        {
            try
            {
               // waveOutSetVolume(0, 0xFFFF); //禁止当前进程发出声音
                CoInternetSetFeatureEnabled(INTERNETFEATURELIST.FEATURE_DISABLE_NAVIGATION_SOUNDS, SET_FEATURE_ON_PROCESS, true);
                uint _savedVolume;
                waveOutGetVolume(IntPtr.Zero, out _savedVolume);

                this.FormClosing += delegate
                {
                    // restore the volume upon exit
                    waveOutSetVolume(IntPtr.Zero, _savedVolume);
                };

                // mute
                waveOutSetVolume(IntPtr.Zero, 0);

            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
}
}