在實際生產環境中，資料庫連線字串需要加密。

先找到ef讀取連線字串的方法：DB.Context.cs

這是預設讀取字串的方法，其對於配置項為：

 <connectionStrings>
    <add name="ConnectionString" connectionString="metadata=res://*/EFYZ.csdl|res://*/EFYZ.ssdl|res://*/EFYZ.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=資料庫連線地址;initial catalog=資料庫名;persist security info=True;user id=user;Password=password;MultipleActiveResultSets=True;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />
  </connectionStrings>
 

在這裡必須讀取解密後發的字串，所以再寫一個方法來獲取解密後的字串EfConstant

using Maticsoft.DBUtility;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Text;

namespace DBUtility
{
   public class EfConstant
    {   /// <summary>
        /// 獲取連線字串
        /// </summary>
        public static string ConnectionString
        {
            get
            {
                string _connectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString; ;
                string ConStringEncrypt = ConfigurationManager.AppSettings["ConStringEncrypt"];
                if (ConStringEncrypt == "true")
                {
                    _connectionString = DESEncrypt.Decrypt(_connectionString);
                }
                return _connectionString;
            }
        }
    }
}
 

然後替換原來的：

   public Entities()
            : base(EfConstant.ConnectionString)
        {

        }

加密連線字串的時候要注意，""是雙引號，加密時要將其改為" "才可以，不然會報出data source關鍵字的錯誤！

 <connectionStrings>
    <add name="ConnectionString" connectionString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providerName="System.Data.EntityClient" />
  </connectionStrings>