使用 |DataDirectory| 时出现“不支持 URI 格式”异常在实体框架连接字符串中

Question

我在 Visual Studio 2012 中有一个单元测试项目，我在其中存储 SQL Server 2012 的 AdventureWorks MDF 文件（该文件名为 AdventureWorks2012_Data.mdf）。在 Visual Studio Server Explorer 中，我可以在数据连接中添加 MDF 并浏览数据库。右键单击 $/Data Connections/AsventureWorks2012_Data.mdf 并选择属性使我可以访问连接字符串，如下所示：

Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\Projects\Common\Source\Framework\Framework.Data.Tests\AdventureWorks2012_Data.mdf;Integrated Security=True;Connect Timeout=30

我将其复制到 app.config 文件中的实体框架连接字符串中，如下所示：

<!-- Works :-) -->
<connectionStrings>
  <add name="AdventureWorksEntities" 
       connectionString="metadata=res://*/Repository2Tests.AdventureWorks.csdl|res://*/Repository2Tests.AdventureWorks.ssdl|res://*/Repository2Tests.AdventureWorks.msl;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\Projects\Common\Source\Framework\Framework.Data.Tests\AdventureWorks2012_Data.mdf;Integrated Security=True;Connect Timeout=30App=EntityFramework&quot;" 
       providerName="System.Data.EntityClient" />
</connectionStrings>

请注意，AttachDbFilename 包含 MDF 文件的完整路径： C:\Projects\Common\Source\Framework\Framework.Data.Tests\AdventureWorks2012_Data.mdf

当我运行单元测试时，一切正常。

我按照“ADO.NET Entity Framework Connection Strings”中的描述将 AttachDbFilename 更改为 |DataDirectory|\AdventureWorks2012_Data.mdf，并按照“ADO.NET |DataDirectory| where is this documented?”中的描述设置 DataDirectory，这样我的连接字符串现在如下所示：

<!-- Doesn't work :-( -->
<connectionStrings>
  <add name="AdventureWorksEntities" 
       connectionString="metadata=res://*/Repository2Tests.AdventureWorks.csdl|res://*/Repository2Tests.AdventureWorks.ssdl|res://*/Repository2Tests.AdventureWorks.msl;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|\AdventureWorks2012_Data.mdf;Integrated Security=True;Connect Timeout=30;App=EntityFramework&quot;" 
       providerName="System.Data.EntityClient" />
</connectionStrings>

使用 |DataDirectory| 的变化导致以下运行时错误：

System.Data.EntityException: The underlying provider failed on ConnectionString. ---> System.ArgumentException: URI formats are not supported.
HResult: -2147024809
at System.IO.Path.NormalizePath(String path, Boolean fullCheck, Int32 maxPathLength)
at System.IO.Path.GetFullPath(String path)
at System.Data.Common.ADP.GetFullPath(String filename)
at System.Data.Common.DbConnectionOptions.ExpandDataDirectory(String keyword, String value, String& datadir)
at System.Data.SqlClient.SqlConnectionString..ctor(String connectionString)
at System.Data.SqlClient.SqlConnectionFactory.CreateConnectionOptions(String connectionString, DbConnectionOptions previous)
at System.Data.ProviderBase.DbConnectionFactory.GetConnectionPoolGroup(DbConnectionPoolKey key, DbConnectionPoolGroupOptions poolOptions, DbConnectionOptions& userConnectionOptions)
at System.Data.SqlClient.SqlConnection.ConnectionString_Set(DbConnectionPoolKey key)
at System.Data.SqlClient.SqlConnection.set_ConnectionString(String value)
at System.Data.EntityClient.EntityConnection.ChangeConnectionString(String newConnectionString)
--- End of inner exception stack trace ---
HResult: -2146233087
at System.Data.EntityClient.EntityConnection.ChangeConnectionString(String newConnectionString)
at System.Data.Entity.Internal.LazyInternalConnection.TryInitializeFromAppConfig(String name, ConnectionStringSettingsCollection connectionStrings)
at System.Data.Entity.Internal.LazyInternalConnection.Initialize()
at System.Data.Entity.Internal.LazyInternalConnection.get_ConnectionHasModel()
at System.Data.Entity.Internal.LazyInternalContext.InitializeContext()
at System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType)
at System.Data.Entity.Internal.Linq.InternalSet`1.Initialize()
at System.Data.Entity.Internal.Linq.InternalSet`1.get_InternalContext()
at System.Data.Entity.Internal.Linq.InternalSet`1.Create()

我已经对此进行了几天的研究，并尝试了无数种变化，但均未成功。我什至调试了 Microsoft 代码，但通过编译器优化，我无法在堆栈上看到任何调试信息。

有人遇到过这个具体问题吗？

Answer 1

当我开始向 Microsoft 提交错误报告并着手复制步骤时，我终于解决了这个问题。

长话短说，问题出在设置 DataDirectory 的代码中：

AppDomain.CurrentDomain.SetData("DataDirectory", dataDirectory);

问题是我的 dataDirectory 变量被初始化为 file://C:/myfolder/etc/ 而不是 C:\myfolder\etc\。我更正了负责该问题的代码，问题得到解决。顺便说一下，我使用的代码是：

// in the test assembly initializer
String dataDirectory = AppDomain.CurrentDomain.GetApplicationPath();
AppDomain.CurrentDomain.SetData("DataDirectory", dataDirectory);

// GetApplicationPath calls into the following extension method
/// <summary>
/// Defines a set of extension methods on <see cref="AppDomain"/> objects.
/// </summary>
public static class AppDomainExtensions
{
    /// <summary>
    /// Gets the application path (works for both ASP.NET and unit tests).
    /// </summary>
    /// <returns></returns>
    public static string GetApplicationPath(this AppDomain appDomain)
    {
        string binPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
        return binPath.Substring(0, binPath.LastIndexOf("bin", StringComparison.InvariantCultureIgnoreCase));
    }
}