NAudio record never receiving a sample

问题:

I'm attempting the simplest possible NAudio example to record from an input device but for some reason I can't get the DataAvailable callback function to be called.

In the example below a break point on Do Something never gets hit.

WaveIn waveIn = new WaveIn();
waveIn.DeviceNumber = 0;
waveIn.DataAvailable += waveIn_DataAvailable;
waveIn.RecordingStopped += new EventHandler(waveIn_RecordingStopped);
waveIn.WaveFormat = new WaveFormat(44100, 1);
waveIn.StartRecording();

private void waveIn_DataAvailable(object sender, WaveInEventArgs e)
{
   Do Something
}

I've checked, re-checked and re-re-checked that the settings are exactly the same as those used by the NAudio VoiceRecorder test application which is able to record audio fine with the exact same settings.

The only difference is my test application is a console application rather than a WPF app. Would that make a difference?

回答1:

Yes, it is because it is a console app, and the WaveIn class uses Windows messages as callbacks. If you are able to download and build the very latest source code from codeplex, you can use the brand new WaveInEvent class (added 6 Mar 2012), which does not rely on a Windows message loop.

Alternatively, if you are familiar with installing pre-release packages using NuGet, you can install the latest NAudio prerelease (currently 1.5.4-beta) which has this class in.

回答2:

Just a though, have you verified your device is valid?

Try something like this;

        int waveInDevices = WaveIn.DeviceCount;
        for (int waveInDevice = 0; waveInDevice < waveInDevices; waveInDevice++)
        {
            WaveInCapabilities deviceInfo = WaveIn.GetCapabilities(waveInDevice);
            MessageBox.Show("Device " + waveInDevice + ": " + deviceInfo.ProductName +
                ", " + deviceInfo.Channels + " channels");
        } 

to verify you have a recording device.

Bernie