解决 QRcode 地址解析中密码可能带@符号、服务器名可能带冒号的问题

关掉 https://github.com/shadowsocks/shadowsocks-csharp/issues/131
我就是爱用中文，哼~

shadowsocks-csharp/Model/Server.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Text;
 using System.IO;
@@ -50,7 +50,8 @@ namespace Shadowsocks.Model
             string[] r1 = Regex.Split(ssURL, "ss://", RegexOptions.IgnoreCase);
             string base64 = r1[1].ToString();
             byte[] bytes = null;
-            for (var i = 0; i < 3; i++) {
+            for (var i = 0; i < 3; i++)
+            {
                 try
                 {
                     bytes = System.Convert.FromBase64String(base64);
@@ -64,11 +65,25 @@ namespace Shadowsocks.Model
             {
                 throw new FormatException();
             }
-            string[] parts = Encoding.UTF8.GetString(bytes).Split(new char[2] { ':', '@' });
-            this.method = parts[0].ToString();
-            this.password = parts[1].ToString();
-            this.server = parts[2].ToString();
-            this.server_port = int.Parse(parts[3].ToString());
+            try
+            {
+                string data = Encoding.UTF8.GetString(bytes);
+                int indexLastAt = data.LastIndexOf('@');
+
+                string afterAt = data.Substring(indexLastAt + 1);
+                int indexLastComma = afterAt.LastIndexOf(':');
+                this.server_port = int.Parse(afterAt.Substring(indexLastComma + 1));
+                this.server = afterAt.Substring(0, indexLastComma);
+
+                string beforeAt = data.Substring(0, indexLastAt);
+                string[] parts = beforeAt.Split(new[] { ':' });
+                this.method = parts[0];
+                this.password = parts[1];
+            }
+            catch (IndexOutOfRangeException)
+            {
+                throw new FormatException();
+            }
         }
     }
 }