csharp: added bindings for context scanning.

I have added the necessary bindings for context scanning. I have implemented it using scan_block.

Signed-off-by: Iacob <[email protected]>

bindings/csharp/CMakeLists.txt

@@ -44,6 +44,7 @@ if (MCS_EXECUTABLE)
 		${CMAKE_CURRENT_SOURCE_DIR}/IOBuffer.cs
 		${CMAKE_CURRENT_SOURCE_DIR}/Trigger.cs
 		${CMAKE_CURRENT_SOURCE_DIR}/IioLib.cs
+		${CMAKE_CURRENT_SOURCE_DIR}/ScanContext.cs
 		${LIBIIO_CS_INFO}
 		)
 

bindings/csharp/ScanContext.cs

@@ -0,0 +1,93 @@
+/*
+ * libiio - Library for interfacing industrial I/O (IIO) devices
+ *
+ * Copyright (C) 2020 Analog Devices, Inc.
+ * Author: Cristian Iacob <[email protected]>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * */
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.InteropServices;
+
+namespace iio
+{
+    /// <summary> <see cref="iio.ScanContext"/> class:
+    /// Class for getting information about the available contexts.</summary>
+    public class ScanContext
+    {
+        private IntPtr scan_block;
+
+        [DllImport("libiio.dll", CallingConvention = CallingConvention.Cdecl)]
+        private static extern IntPtr iio_create_scan_block([In] string backend, uint flags);
+
+        [DllImport("libiio.dll", CallingConvention = CallingConvention.Cdecl)]
+        private static extern IntPtr iio_scan_block_get_info(IntPtr blk, uint index);
+
+        [DllImport("libiio.dll", CallingConvention = CallingConvention.Cdecl)]
+        private static extern IntPtr iio_context_info_get_description(IntPtr info);
+
+        [DllImport("libiio.dll", CallingConvention = CallingConvention.Cdecl)]
+        private static extern IntPtr iio_context_info_get_uri(IntPtr info);
+
+        [DllImport("libiio.dll", CallingConvention = CallingConvention.Cdecl)]
+        private static extern long iio_scan_block_scan(IntPtr blk);
+
+        /// <summary>
+        /// Gets the uri and the description of all available contexts with USB backend. 
+        /// </summary>
+        /// <returns>a <see cref="Dictionary{String, String}"/> containing the context's uri as key and its description as value.</returns>
+        public Dictionary<string, string> get_usb_backend_contexts()
+        {
+            this.scan_block = iio_create_scan_block("usb", 0);
+            return get_contexts_info();
+        }
+
+        // <summary>
+        /// Gets the uri and the description of all available contexts with local backend. 
+        /// </summary>
+        /// <returns>a <see cref="Dictionary{String, String}"/> containing the context's uri as key and its description as value.</returns>
+        public Dictionary<string, string> get_local_backend_contexts()
+        {
+            this.scan_block = iio_create_scan_block("local", 0);
+            return get_contexts_info();
+        }
+
+        // <summary>
+        /// Gets the uri and the description of all available contexts from dns_sd backend. 
+        /// </summary>
+        /// <returns>a <see cref="Dictionary{String, String}"/> containing the context's uri as key and its description as value.</returns>
+        public Dictionary<string, string> get_dns_sd_backend_contexts()
+        {
+            this.scan_block = iio_create_scan_block("ip", 0);
+            return get_contexts_info();
+        }
+
+        private Dictionary<string, string> get_contexts_info()
+        {
+            uint contexts_count = (uint)iio_scan_block_scan(this.scan_block);
+            Dictionary<string, string> contexts_info = new Dictionary<string, string>();
+
+            for (uint i = 0; i < contexts_count; i++)
+            {
+                IntPtr info = iio_scan_block_get_info(this.scan_block, i);
+                string uri = Marshal.PtrToStringAnsi(iio_context_info_get_uri(info));
+                string description = Marshal.PtrToStringAnsi(iio_context_info_get_description(info));
+                contexts_info[uri] = description;
+            }
+
+            return contexts_info;
+        }
+    }
+}