Entity FrameWork 配置 之连接字符串隐藏或重用

//新建类
public class DALBase
    {
        public EnforcementEntities EnforcementContext { get; set; }

        public DALBase()
        {
            //这里是链接字符串 1.可以写在类里面 2.可以写在单独的文件里面，通过程序进度读取。
            string providerString = "Data Source=.;Initial Catalog=Enforcement;uid=sa;password=ok;";
            string conn = GetEntityConnString(providerString);
            EnforcementContext = new EnforcementEntities(conn);
        }

        private string GetEntityConnString(string providerString)
        {
            EntityConnectionStringBuilder entityBuilder = new EntityConnectionStringBuilder();
            //Metadata属性的值，是从向导生成的Config粘贴过来的Model1是默认的edmx文件。
            entityBuilder.Metadata = "res://*/Model1.csdl|res://*/Model1.ssdl|res://*/Model1.msl";
            entityBuilder.ProviderConnectionString = providerString;
            entityBuilder.Provider = "System.Data.SqlClient";
            return entityBuilder.ToString();
        }
    }