转移.net core 3.1，为.NET 5做准备

Infrastructure/Helpers/Md5.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Security.Cryptography;
+using System.Text;
+
+namespace Infrastructure.Helpers
+{
+    public class Md5
+    {
+        public static string Encrypt(string str)
+        {
+
+            string pwd = String.Empty;
+
+            MD5 md5 = MD5.Create();
+
+            // 编码UTF8/Unicode　
+            byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(str));
+
+            // 转换成字符串
+            for (int i = 0; i < s.Length; i++)
+            {
+                //格式后的字符是小写的字母
+                //如果使用大写（X）则格式后的字符是大写字符
+                pwd = pwd + s[i].ToString("X");
+
+            }
+
+            return pwd;
+        }
+    }
+}