昨天经过Terrylee  的指出后，又找出了Microsoft Enterprise Library June 2005的源代码，仔细的看了看。
总觉得这个是个bug。
          我又找到了src\Data\Tests这个目录下的ConnectionStringFixture.cs测试文件。经过我的测试，我确定这是一个小bug.
          这面就是经测试经过：
          原来的ConnectionStringFixture.cs文件，没有做任何修改。
          源代码如下：

using System;
using NUnit.Framework;

namespace Microsoft.Practices.EnterpriseLibrary.Data.Tests
{
    [TestFixture]
    public class ConnectionStringFixture
    {
        private static readonly string userName = "User";
        private static readonly string password = "Password";
        private static readonly string userIdTokens = "user id=,uid=";
        private static readonly string passwordTokens = "password=,pwd=";
        private ConnectionString connectionString;

        [Test]
        [ExpectedException(typeof(InvalidOperationException))]
        public void InvalidOperationExceptionThrownWhenConnectionStringIsNull()
        {
            this.connectionString = new ConnectionString(null, userIdTokens, passwordTokens);
            string password = this.connectionString.Password;
            Assert.IsTrue(password != null);
        }

        [Test]
        public void EmptyCredentialsReturnedForEmptyConnectionString()
        {
            this.connectionString = new ConnectionString(string.Empty, userIdTokens, passwordTokens);
            Assert.AreEqual(0, this.connectionString.UserName.Length);
            Assert.AreEqual(0, this.connectionString.Password.Length);
        }

        [Test]
        public void CanGetCredentialsFromRealSqlDataClass()
        {
            string initialConnectionString = String.Format("server=localhost; database=JoeRandom; uid={0}; pwd={1}; ;", userName, password);
            this.connectionString = new ConnectionString(initialConnectionString, userIdTokens, passwordTokens);
            Assert.AreEqual(userName, this.connectionString.UserName);
            Assert.AreEqual(password, this.connectionString.Password);
        }

        [Test]
        public void CreateNewConnectionStringTest()
        {
            string initialConnectionString = String.Format("server=localhost; database=JoeRandom; uid={0}; pwd={1}; ;", userName, password);
            this.connectionString = new ConnectionString(initialConnectionString, userIdTokens, passwordTokens).CreateNewConnectionString(initialConnectionString);
            Assert.AreEqual(userName, this.connectionString.UserName);
            Assert.AreEqual(password, this.connectionString.Password);
        }

        [Test]
        public void CanGetCredentialsUsingAlternatePatternsForUidAndPwd()
        {
            string initialConnectionString = String.Format("server=localhost; database=JoeRandom; user id={0}; password={1}; ;", userName, password);
            this.connectionString = new ConnectionString(initialConnectionString, userIdTokens, passwordTokens);
            Assert.AreEqual(userName, this.connectionString.UserName);
            Assert.AreEqual(password, this.connectionString.Password);
        }

        [Test]
        public void CanAddCredentialsToConnectionStringThatDoesNotHaveThem()
        {
            string initialConnectionString = "server=localhost; database=RandomData; ; ;";
            this.connectionString = new ConnectionString(initialConnectionString, userIdTokens, passwordTokens);
            this.connectionString.UserName = userName;
            this.connectionString.Password = password;
            string actualConnectionString = String.Format("server=localhost; database=RandomData; ; ;user id={0};password={1};",
                                                          userName, password);
            Assert.AreEqual(actualConnectionString, this.connectionString.ToString());
        }

        [Test]
        public void CanSetUserIdAndPasswordInConnectionStringThatAlreadyHasOne()
        {
            string initialConnectionString = String.Format("server=localhost; database=JoeRandom; user id={0}; password={1}; ;", "Kill", "Bill");
            ConnectionString newConnectionString = new ConnectionString(initialConnectionString, userIdTokens, passwordTokens);
            newConnectionString.UserName = userName;
            newConnectionString.Password = password;
            string actualConnectionString = String.Format("server=localhost; database=JoeRandom; user id={0}; password={1}; ;", userName, password);
            Assert.AreEqual(actualConnectionString, newConnectionString.ToString());
        }

        /// <summary>
        /// Test to see if ToStringNoCredentials works properly for a connection string 
        /// without a username and password
        /// </summary>
        [Test]
        public void RemovingCredentialsFromConnectionStringWithoutThemIsOk()
        {
            string initialConnectionString = "server=localhost;database=RandomData;";
            ConnectionString newConnectionString = new ConnectionString(initialConnectionString, userIdTokens, passwordTokens);
            string expectedConnectionString = "server=localhost;database=randomdata;";
            string strippedConnectionString = newConnectionString.ToStringNoCredentials();
            Assert.AreEqual(expectedConnectionString, strippedConnectionString);
        }

        /// <summary>
        /// Test to see that ToStringNoCredentials removes the username and password
        /// </summary>
        [Test]
        public void WillRemoveCredentialsFromConnectionString()
        {
            string initialConnectionString = "server=localhost;database=RandomData;user id=Bill;pwd=goodPassword";
            ConnectionString newConnectionString = new ConnectionString(initialConnectionString,
                                                                        userIdTokens, passwordTokens);
            string expectedConnectionString = "server=localhost;database=randomdata;";
            string strippedConnectionString = newConnectionString.ToStringNoCredentials();
            Assert.AreEqual(expectedConnectionString, strippedConnectionString);
        }

        [Test]
        public void NullTests()
        {
            ConnectionString connectionString = new ConnectionString(null, null, null);
            Assert.AreEqual(string.Empty, connectionString.ToStringNoCredentials());
        }
    }
}

 测试结果：
  
  测试全部通过。

  
  新的ConnectionStringFixture.cs文件，做了两处修改。其他什么也没修改。
  原来的：private static readonly string userIdTokens = "user id=,uid=";       
  修改后:private static readonly string userIdTokens = "User Id=,Uid="; //只在此处修改
         
  原来的：private static readonly string passwordTokens = "password=,pwd=";
    修改后：private static readonly string passwordTokens = "Password=,Pwd=";//只在此处修改
   
   
    测试结果：
  
      测试有些没有通过。
  
      大家可以自己做个测试。
      所以我认为，这是Microsoft Enterprise Library June 2005的一个小bug，不在是疑似。
      不对的地方请指正。

出处：https://www.cnblogs.com/chillsrc/archive/2006/03/21/354542.html