Add C# TTS API (#399)

dotnet-examples/TTS/PlayAudioPartial/SherpaOnnxGeneratedAudioResultPlayAudio.cs

@@ -0,0 +1,44 @@
+using NAudio.Wave;
+
+namespace TTS.Struct
+{
+    public sealed partial class SherpaOnnxGeneratedAudioResult
+    {
+        private WaveOutEvent waveOut;
+        private WaveFormat waveFormat;
+        private BufferedWaveProvider bufferedWaveProvider;
+
+        private int bufferLength = 1;
+
+        public TimeSpan? AudioDuration => bufferedWaveProvider?.BufferedDuration;
+
+        public float PlayProgress => (waveOut?.GetPosition() * 1.0f / bufferLength).Value;
+
+        public void Play()
+        {
+            waveOut ??= new WaveOutEvent();
+
+            waveFormat ??= new WaveFormat(sample_rate, AudioDataBit, Channels); // 32-bit 浮点，单声道
+
+            if (bufferedWaveProvider == null)
+            {
+                bufferedWaveProvider ??= new BufferedWaveProvider(waveFormat);
+
+                var buffer = AudioByteData;
+
+                bufferLength = buffer.Length;
+
+                bufferedWaveProvider.AddSamples(buffer, 0, bufferLength);
+                bufferedWaveProvider.BufferLength = bufferLength;
+                waveOut.Init(bufferedWaveProvider);
+            }
+            waveOut.Play();
+        }
+
+        public void Stop()
+        {
+            waveOut?.Stop();
+        }
+
+    }
+}