Split online.cs and offline.csFile (#941)

Co-authored-by: 东风破 <birdfishs@163.com>

scripts/dotnet/FeatureConfig.cs

@@ -0,0 +1,32 @@
+/// Copyright (c)  2023  Xiaomi Corporation (authors: Fangjun Kuang)
+/// Copyright (c)  2023 by manyeyes
+/// Copyright (c)  2024.5 by 东风破
+
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.InteropServices;
+using System.Text;
+using System;
+
+namespace SherpaOnnx
+{
+    /// It expects 16 kHz 16-bit single channel wave format.
+    [StructLayout(LayoutKind.Sequential)]
+    public struct FeatureConfig
+    {
+        public FeatureConfig()
+        {
+            SampleRate = 16000;
+            FeatureDim = 80;
+        }
+        /// Sample rate of the input data. MUST match the one expected
+        /// by the model. For instance, it should be 16000 for models provided
+        /// by us.
+        public int SampleRate;
+
+        /// Feature dimension of the model.
+        /// For instance, it should be 80 for models provided by us.
+        public int FeatureDim;
+    }
+
+}