我可以将连接字符串与WCF中的端点相关联吗？

我们有一个连接到数据库的WCF REST服务。事实上，我们有多个数据库实例，都具有相同的模式

我们希望为每个数据库实例设置一个端点，并将连接字符串与端点关联。该服务将读取连接字符串并连接到相应的SQL Server实例

我相信这是可能的；这是个好主意吗？我如何设置它？有关于MSDN的文档吗

---

编辑：我找到了，答案建议在标题中添加客户端的连接信息。出于安全考虑，我不想这样做，因为我确实希望每个数据库都有一个不同的uri。

为什么不添加一个新参数，指定调用将连接的数据库是什么

例如：

• 您可以添加一个

  db

  参数，该参数将获得一个数字，然后从那里连接
• 您可以在身份验证方法上添加此类参数

作为第一项的示例：

public ProductItem GetProduct(int productId, int db = 1)
{
    ProductItem product = new ProductItem();
    string connectionString = getConnectionStringForDb(db);

    using (SqlConnection connection =
        new SqlConnection(connectionString))
    {
        SqlCommand command = new SqlCommand("SELECT name, price FROM Products WHERE productId = @product;", connection);
        command.Parameters.AddWithValue("@product", productId);

        try
        {
            connection.Open();
            SqlDataReader reader = command.ExecuteReader();
            reader.Read();

            product = new product({
                Name = reader[0],
                Price = reader[1]
            });

            reader.Close();
        }
        catch (Exception ex)
        {
            // Log exception
        }
    }

    return product;
}

采取

只需将您的连接字符串添加到

web.config

和name中，然后如下所示：

DBConnectionString_1, DBConnectionString_2, DBConnectionString_3

或者任何对你有意义的事情

<connectionStrings>
  <add 
    name="DBConnectionString_1" 
    connectionString="Data Source=serverName;Initial 
    Catalog=Northwind;Persist Security Info=True;User 
    ID=userName;Password=password"
    providerName="System.Data.SqlClient"
  />
  <add 
    name="DBConnectionString_2" 
    connectionString="Data Source=serverName;Initial 
    Catalog=Northwind;Persist Security Info=True;User 
    ID=userName;Password=password"
    providerName="System.Data.SqlClient"
  />
  <add 
    name="DBConnectionString_3" 
    connectionString="Data Source=serverName;Initial 
    Catalog=Northwind;Persist Security Info=True;User 
    ID=userName;Password=password"
    providerName="System.Data.SqlClient"
  />
</connectionStrings>

---

在web.config中使用此选项：

<configuration>

  <appSettings>
    <add key="Foo.svc" value="tagvalue1"/>
  </appSettings>
  ...

---

这比我想象的要难一些。WCF有很多扩展点，很难选择正确的扩展点。请回答或评论，如果你认为有更好的方法，或与此有关的任何错误

我已经决定使用一个实现和的自定义类。我有一个派生自的类，它允许我将行为与配置中的端点相关联。你可以这样做

我的

DatabaseConnectionContext

类如下所示：

/// <summary>
/// An endpoint behavior that associates a database connection string name with the endpoint and adds it to the
/// properties of incoming messages.
/// </summary>
public class DatabaseConnectionContext : IEndpointBehavior, IDispatchMessageInspector
{
    /// <summary>
    /// Initializes a new instance of the <see cref="DatabaseConnectionContext"/> class with the provided connection string name.
    /// </summary>
    /// <param name="connectionStringName">The name of the connection string to associate with the endpoint.</param>
    public DatabaseConnectionContext(string connectionStringName)
    {
        this.ConnectionStringName = connectionStringName;
    }

    /// <summary>
    /// Gets the name of the connection string to associate with the endpoint.
    /// </summary>
    public string ConnectionStringName { get; private set; }

    /// <inheritdoc />
    public void AddBindingParameters(ServiceEndpoint endpoint, BindingParameterCollection bindingParameters)
    {
    }

    /// <inheritdoc />
    public void ApplyClientBehavior(ServiceEndpoint endpoint, ClientRuntime clientRuntime)
    {
        throw new NotImplementedException();
    }

    /// <inheritdoc />
    public void ApplyDispatchBehavior(ServiceEndpoint endpoint, EndpointDispatcher endpointDispatcher)
    {
        endpointDispatcher.DispatchRuntime.MessageInspectors.Add(this);
    }

    /// <inheritdoc />
    public void Validate(ServiceEndpoint endpoint)
    {
    }

    /// <inheritdoc />
    public object AfterReceiveRequest(ref Message request, IClientChannel channel, InstanceContext instanceContext)
    {
        request.Properties["connectionStringName"] = this.ConnectionStringName;
        return null;
    }

    /// <inheritdoc />
    public void BeforeSendReply(ref Message reply, object correlationState)
    {
    }
}

/// <summary>
/// Associates a <see cref="DatabaseConnectionContext"/> with an endpoint in configuration.
/// </summary>
public class DatabaseConnectionContextBehaviorExtension : BehaviorExtensionElement
{
    /// <summary>
    /// The name of the <see cref="ConnectionStringName"/> property when it appears in a configuration file.
    /// </summary>
    private const string ConnectionStringNamePropertyName = "connectionStringName";

    /// <summary>
    /// Gets or sets the name of the configuration string to associate with the endpoint.
    /// </summary>
    [ConfigurationProperty(ConnectionStringNamePropertyName)]
    public string ConnectionStringName
    {
        get
        {
            return (string)this[ConnectionStringNamePropertyName];
        }

        set
        {
            this[ConnectionStringNamePropertyName] = value;
        }
    }

    /// <inheritdoc />
    public override Type BehaviorType
    {
        get { return typeof(DatabaseConnectionContext); }
    }

    /// <inheritdoc />
    protected override object CreateBehavior()
    {
        return new DatabaseConnectionContext(this.ConnectionStringName);
    }
}

<behaviors>

  <endpointBehaviors>
    <behavior name="DevRestEndpointConfiguration">
      <webHttp helpEnabled="false" />
      <connectionStringInterceptor connectionStringName="myDevConnectionStringName" />
    </behavior>
    <behavior name="ProductionRestEndpointConfiguration">
      <webHttp helpEnabled="false" />
      <connectionStringInterceptor connectionStringName="myProductionConnectionStringName" />
    </behavior>
  </endpointBehaviors>

</behaviors>

<extensions>
  <behaviorExtensions>
    <add name="connectionStringInterceptor" type="DatabaseConnectionContextBehaviorExtension, MyAssembly, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" />
  </behaviorExtensions>
</extensions>

My web.config包含如下内容：

/// <summary>
/// An endpoint behavior that associates a database connection string name with the endpoint and adds it to the
/// properties of incoming messages.
/// </summary>
public class DatabaseConnectionContext : IEndpointBehavior, IDispatchMessageInspector
{
    /// <summary>
    /// Initializes a new instance of the <see cref="DatabaseConnectionContext"/> class with the provided connection string name.
    /// </summary>
    /// <param name="connectionStringName">The name of the connection string to associate with the endpoint.</param>
    public DatabaseConnectionContext(string connectionStringName)
    {
        this.ConnectionStringName = connectionStringName;
    }

    /// <summary>
    /// Gets the name of the connection string to associate with the endpoint.
    /// </summary>
    public string ConnectionStringName { get; private set; }

    /// <inheritdoc />
    public void AddBindingParameters(ServiceEndpoint endpoint, BindingParameterCollection bindingParameters)
    {
    }

    /// <inheritdoc />
    public void ApplyClientBehavior(ServiceEndpoint endpoint, ClientRuntime clientRuntime)
    {
        throw new NotImplementedException();
    }

    /// <inheritdoc />
    public void ApplyDispatchBehavior(ServiceEndpoint endpoint, EndpointDispatcher endpointDispatcher)
    {
        endpointDispatcher.DispatchRuntime.MessageInspectors.Add(this);
    }

    /// <inheritdoc />
    public void Validate(ServiceEndpoint endpoint)
    {
    }

    /// <inheritdoc />
    public object AfterReceiveRequest(ref Message request, IClientChannel channel, InstanceContext instanceContext)
    {
        request.Properties["connectionStringName"] = this.ConnectionStringName;
        return null;
    }

    /// <inheritdoc />
    public void BeforeSendReply(ref Message reply, object correlationState)
    {
    }
}

/// <summary>
/// Associates a <see cref="DatabaseConnectionContext"/> with an endpoint in configuration.
/// </summary>
public class DatabaseConnectionContextBehaviorExtension : BehaviorExtensionElement
{
    /// <summary>
    /// The name of the <see cref="ConnectionStringName"/> property when it appears in a configuration file.
    /// </summary>
    private const string ConnectionStringNamePropertyName = "connectionStringName";

    /// <summary>
    /// Gets or sets the name of the configuration string to associate with the endpoint.
    /// </summary>
    [ConfigurationProperty(ConnectionStringNamePropertyName)]
    public string ConnectionStringName
    {
        get
        {
            return (string)this[ConnectionStringNamePropertyName];
        }

        set
        {
            this[ConnectionStringNamePropertyName] = value;
        }
    }

    /// <inheritdoc />
    public override Type BehaviorType
    {
        get { return typeof(DatabaseConnectionContext); }
    }

    /// <inheritdoc />
    protected override object CreateBehavior()
    {
        return new DatabaseConnectionContext(this.ConnectionStringName);
    }
}

<behaviors>

  <endpointBehaviors>
    <behavior name="DevRestEndpointConfiguration">
      <webHttp helpEnabled="false" />
      <connectionStringInterceptor connectionStringName="myDevConnectionStringName" />
    </behavior>
    <behavior name="ProductionRestEndpointConfiguration">
      <webHttp helpEnabled="false" />
      <connectionStringInterceptor connectionStringName="myProductionConnectionStringName" />
    </behavior>
  </endpointBehaviors>

</behaviors>

<extensions>
  <behaviorExtensions>
    <add name="connectionStringInterceptor" type="DatabaseConnectionContextBehaviorExtension, MyAssembly, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" />
  </behaviorExtensions>
</extensions>

---

部分中的每个

元素都将其

行为配置设置为
部分中相应元素的名称。
我非常喜欢这个建议。它适用于REST服务，其中URI的一部分可以很容易地作为参数传递给服务方法。然而，我使用了另一种解决方案，请参阅我自己的回复，因为我认为如果我们稍后公开SOAP端点，它会工作得更好。此外，我们不一定希望web.config中显示的每个连接字符串都可用。