转移.net core 3.1，为.NET 5做准备

Infrastructure/CommonException.cs

@@ -0,0 +1,22 @@
+
+using System;
+
+namespace Infrastructure
+{
+    public class CommonException : Exception
+    {
+        private int _code;
+
+        public CommonException(string message, int code)
+            : base(message)
+        {
+            this._code = code;
+        }
+
+        public int Code
+        {
+            get { return _code; }
+        }
+
+    }
+}