添加C#sdk

sop-sdk/sdk-csharp/SDKCSharp/Common/SopSignature.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Text;
+
+namespace SDKCSharp.Common
+{
+    public class SopSignature
+    {
+        public SopSignature()
+        {
+        }
+
+        public static String getSignContent(Dictionary<string, string> form)
+        {
+            StringBuilder content = new StringBuilder();
+            List<string> keys = new List<string>(form.Keys);
+
+            keys.Sort();
+            int index = 0;
+            for (int i = 0; i < keys.Count; i++)
+            {
+                string key = keys[i];
+                string value = form[key];
+                if (!string.IsNullOrEmpty(key) && !string.IsNullOrEmpty(value))
+                {
+                    content.Append((index == 0 ? "" : "&") + key + "=" + value);
+                    index++;
+                }
+            }
+            return content.ToString();
+        }
+    }
+}